Highlights Volume 26, Issue 1, 2021

www.squ.edu.om/agr/JAMS JAMS Journal of Agricultural and Marine Sciences

Soil and water sampling sites.

• Spatial and Temporal Assessment of Vegetation Cover in Al- Suwaiq Using Satellite Images Analysis • Effect of Storage Conditions on Postharvest Quality of Tomatoes: A Case Study at Market-Level • Subclinical Mastitis in Camels in Oman: A Pilot Study • Biological Efficiency and Control of a Membrane Bioreactor and Conventional Activated Sludge Process for Treating Municipal Wastewater • Mean Sea Level Variability along the Northern Coast of the Oman Sea and its Response to Monsoon and the North Atlantic Oscillation Index from Tide Gauge Measurement • Protective effect of Oxalis corniculate and Pteropyrum scoparium Leaf Extracts against Azoxymethane-induced oxidative stress and colon carcinogenesis • Microbiological Assessment of Locally Dried Fish in Oman: Technical Note • Correlation between Sensory and Instrumental Textural Attributes of Date Palm (Phoenix dactylifera L.) fruits: Technical Note • Effect of COVID-19 pandemic situation on the teaching of Graduation Projects and Internship type courses in undergraduate degree programs A Sultan Qaboos University Research Journal Journal of Agricultural and Marine Sciences (JAMS( JAMS is an international peer-reviewed journal that publishes original fundamental and applied research articles in a wide variety of disciplines of the agricultural and marine sciences. The journal provides a forum for specialists and practitioners and brings together quality papers dealing with agricultural economics, natural resource economics, animal and veterinary sciences, bio-resources, biotechnologies, soil sciences, water management, agricultural engineering, fisheries, marine sciences, food science, human nutrition, plant production, plant protection, rural environment, coastal zone management and oceanography. All issues of the Journal of Agricultural and Marine Sciences are freely available online and do not carry any publication charges.

Sultan Qaboos University Academic Publication Board Chair, Academic Publication Board Dr. Abdullah Ambusaidi Prof. Lamk Al-Lamki Dr. Yahya Al-Wahaibi Prof. Shafiur Rahman Dr. Ibrahim Metwally Mr. Jamal Al-Ghailani Prof. Mohammad S. Khan Dr. Mohammed Al-Saqri

JAMS Editorial Board

Prof. Shafiur Rahman (Editor-in-Chief) Dr. Muhammad Farooq (Editor)

Associate Editors

Dr. Ali Al-Maktoomi Dr. Haytham Alieldin Ali Dr. Waleed Al-Marzooqi Dr. Daniel Blackburn Dr. Lokman Zaibet Dr. Hemanatha P W Jayasuriya Dr. Zaher Al-Attabi Dr. Velazhahan Rethinasamy Dr. Rhonda Janke Dr. Michel R. Claereboudt Prof. Anvar Kacimov Dr. Mohamed Essa Musthafa Dr. Wenresti Glino Gallardo

International Advisory Board Prof. James W. Oltjen, University of California, USA Prof. Paul Moughan, Massey University, New Zealand Prof. Donald C. Slack, University of Arizona, USA Prof. R. Paul Singh, University of California, USA Prof. Stephan Kasapis, RMIT University, Australia Prof. Christopher D. Lu, University of Hawaii, USA Prof. Mattheus Goosen, Alfaisal University, Saudi Arabia Prof. Ewen McLean, Virginia Polytechnic, USA Prof. Ching Yuan Hu, University of Hawaii, USA

Technical Assistant: Alia Ali Al-Rutani

TheJournal of Agricultural and Marine Sciences (JAMS) is published by Sultan Qaboos University, P.O. Box 50, Al-Khod 123, Muscat, Sultanate of Oman. Year of issue: 2020

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Manuscript submission is made through an online management system at journals.squ.edu.om/index.php/jams Alternatively, if internet access is difficult, manuscripts can be emailed [email protected] Please see Guidelines for Authors at journals.squ.edu.om/index.php/jams/about/submissions#authorGuidelines Contents

Research Papers

Spatial and Temporal Assessment of Vegetation Cover in Al- Suwaiq Using Satellite Images Analysis 01 Kathiya Al-Aufi, Malik Al-Wardy, Bheemanagoud Choudri, Mushtaque Ahmed, Ghazi Al-Rawas, Yaseen Al-Mulla Effect of Storage Conditions on Postharvest Quality of Tomatoes: A Case Study at Market-Level 13 Mai Al-Dairi, Pankaj B. Pathare, Adil Al-Mahdouri Subclinical Mastitis in Camels in Oman: A Pilot Study 21 Muhammad Nadeem Asi, Waleed Al-Marzooqi, Yasmin ElTahir, Al Ghaly, Al Toobi, Sara Al Raisi, Haytham Ali, Elshafie I. Elshafie, Eugene H. Johnson Biological Efficiency and Control of a Membrane Bioreactor and Conventional Activated Sludge Process for Treating Municipal Wastewater 27 Buthaina Mahfoud Alwahaibi, Abdullah Al-Mamun, Mahad Said Baawain, Ahmed Sana Mean Sea Level Variability along the Northern Coast of the Oman Sea and its Response to Monsoon and the North Atlantic Oscillation Index from Tide Gauge Measurement 37 S. Hassanzadeh, F. Hosseinibalam Protective effect of Oxalis corniculate and Pteropyrum scoparium Leaf Extracts against Azoxymethane-induced oxidative stress and colon carcinogenesis 47 Mostafa I. Waly, Mohammed Al-Khusaibi, Nejib Guizani

Technical notes

Microbiological Assessment of Locally Dried Fish in Oman: Technical Note 53 Aaisha K. Al-Saadia, Abdulrahim M. Al-Ismaili a, Mohammed Al-Ruzeikib, Ismail M. Al-Bulushi Correlation between Sensory and Instrumental Textural Attributes of Date Palm (Phoenix dactylifera L.) fruits: Technical Note 57 Vandita Singh, Mohammad Shafiur Rahman, Nejib Guizani, Hakikulla Shah

Perspective Papers

Effect of COVID-19 pandemic situation on the teaching of Graduation Projects and Internship type courses in undergraduate degree programs 62 Hemanatha P. W. Jayasuriya JAMS: Guidelines for authors 66 Journal of Agricultural and Marine Sciences 2021, 26(1): 1–12 DOI: 10.24200/jams.vol26iss1pp1-12 Reveived 20 July 2020 Accepted 07 Nov 2020 Research Paper Spatial and Temporal Assessment of Vegetation Cover in Al- Suwaiq Using Satellite Images Analysis

Kathiya Al-Aufi1, Malik Al-Wardy1*, Bheemanagoud Choudri2, Mushtaque Ahmed1, Ghazi Al-Rawas3, Yaseen Al-Mulla1

التقييم املكاين والزماين للغطاء النبايت يف والية السويق وحتليله ابستخدام صور األقمار الصناعية كاذية العويف1 ومالك الوردي1* وبيماانغود تشودري2 ومشتاق أمحد1 وغازي الرواس3 وايسني املال1 Abstract. Digital change detection techniques using multi-temporal satellite imagery help in understanding land- scape dynamics. This study assesses the spatial and temporal dynamics of vegetation cover change in the coastal wilayat of Al-Suwaiq, Sultanate of Oman, using field and remote sensing data. The study was conducted at selected distances from the coastline, considering the variability in soil and water salinity. Normalized Difference Vegetation Index was calculated using the Landsat 5 TM and Landsat 8 OLI satellite images and classified into three main classes to evaluate the monthly and annual vegetation cover change between 1987 and 2016. Soil and water samples were collected during the cultivated season in Al-Suwaiq and analyzed mainly for salinity. Vegetation cover maps showed a general shift in vegetation biomass from regions closer to the coast (north-side) as water salinity increased with time. Between 1988 and 1999, vegetation cover in the total study area increased by 7.7%, whereas it declined by 1.5 % along the coast. How- ever, between 1999 and 2016, the vegetation cover decreased further by 5% along the coast while increasing by 12.2%, mainly 3-6 km from the coast. The largest increase in the area was for vegetation covers falling within the moderate (0.33-0.67) and high (0.67-0.86) NDVI classes. In conclusion, vegetation cover in Al-Suwaiq reduced along the coastline and shifted agriculture activities and increased cultivation from the North to the South of Wilayat. Therefore, agriculture activities on the Southside of the Wilayat should be controlled to prevent further degradation of water quality and its possible effect on agricultural farmlands. Keywords: Landsat; NDVI; Vegetation cover; Change detection; Al-Suwaiq; Soil salinity; Water salinity. :تلعب املســتخلصصــور األقمــار الصناعيــة والتقنيــات الرقميــة املتصلــة هبــا دورا مهمــا يف فهــم ديناميــة التغــر يف الغطــاء النبــايت علــى األرض. وتقيّــم هــذه الدراســة الديناميــات املكانيــة والزمانيــة لتغــر الغطــاء النبــايت يف واليــة الســويق يف ســلطنة عمــان ابســتخدام البيــاانت امليدانيــة وبيــاانت االستشــعار عــن بعــد. وأجريــت هــذه الدراســة علــى مســافات حمــددة مــن الســاحل آخــذةًيف االعتبــار التبايــن املوجــود يف ملوحــة الرتبــة وامليــاه يف منطقــة الدراســة، حيــث مت حســاب مؤشــر التغــر للغطــاء النبــايت ابســتخدام صــور القمــر الصناعــي الندســات 5 والقمــر الندســات ، 8ومــن مث تصنيــفالغطــاء النبــايت إىل ثــالث فئــات رئيســة لتقييــمالتغــر الشــهري والســنوي يف الغطــاء النبــايت بــني عامــي 1987 و .2016 ومت أيضــا ًمجــع عينــات مــن الرتبــة وامليــاه مــن املــزارع الــي تقــع يف منطقــة الدراســة يف واليــة الســويق وحتليــل معايــر امللوحــة فيهــا. وأظهــرت خرائــط الغطــاء النبــايت تغــراًعامــا يف الكتلــة احليويــة للغطــاء النبــايت يف املناطــق القريبــة مــن الســاحل )مشــال منطقــة الدراســة( بســبب متلــح امليــاه مــع مــرور الوقــت وحتوهلــا اىل اجلهــة اجلنوبيــة، حيــث زادت مســاحة الغطــاء النبــايت اإلمجاليــة يف منطقــة الدراســة بــني عامــي 1988 و 1999 بنســبة %،7.7 بينمــا اخنفضــت هــذه النســبة مبقــدار %1.5 علــى طــول الســاحل يف نفــس الفــرتة، وزادت نســبة اإلخنفــاض هــذه علــى طــول الســاحل إضافيــا يف الفــرتة مــا بــني عامــي 1999 و 2016 مبقــدار 5%، بينمــا زادت هــذه النســبة مــن مســاحة الغطــاء النبــايت بشــكل إضــايف ويف نفــس الفــ ةرت مبقــدار 12.2% علــى مســافة 3-6 كيلومــرت مــن الســاحل.وكانــت الــزايدة األكــر يف املســاحة هــي للغطــاء النبــايت الواقــع ضمــن فئتــني ملؤشــر التغــر للغطــاء النبــايت ومهــا املعتدلــة )0.33-0.67( والعاليــة )0.67- (. 0.86ويف اخلتــام خلصــت الدراســة إىل تقلــص الغطــاء النبــايت علــى طــول الســاحل يف واليــة الســويق وحتولــت األنشــطة والرقعــة الزراعيــة مــن مشــال منطقــة الدراســة إىل جنوهبــا، ولذلــك وجــب مراقبــة األنشــطة الزراعيــة الواقعــة يف اجلهــة اجلنوبيــة ملنــع املزيــد مــن التدهــور يف جــودة امليــاه وأتثيهــا احملتمــل علــى األراضــي الزراعيــة. الكلمات املفتاحية: الندسات، مؤشر التغي للغطاء النبايت، الغطاء النبايت، كشف التغيي، السويق، ملوحة الرتبة، ملوحة املياه Introduction cover can be used as an indicator of land degradation and desertification in arid and semi-arid lands. Further- he detection of vegetation cover change can help more, the estimation of vegetation cover is essential for for a better understanding of the interactions livestock breeding, agriculture, and helping land manag- between humans and the ecosystem (Aly et al., ers to minimize the danger of soil salinization (Wiegand 2016). According to Purevdorj et al. (1998), vegetation et al., 1994). T 1 1 ,* Malik Al-Wardy ( ) [email protected], Department of Soils, Spatial and temporal changes in vegetation cover can Water, and Agricultural Engineering, College of Agricultural and Ma- 2 be effectively and rapidly observed by remote sensing rine Sciences, Sultan Qaboos University, Muscat, Oman. Center for Environmental Studies and Research, Sultan Qaboos University, Mus- techniques using different vegetation indices (Alhamma- 3 cat, Oman. Department of Civil and Architectural Engineering, Col- di and Glenn, 2008). Vegetation indices (VI) determine lege of Engineering, Sultan Qaboos University, Muscat, Oman. vegetation cover by collecting useful information about Spatial and Temporal Assessment of Vegetation Cover in Al- Suwaiq Using Satellite Images Analysis

the vegetation such as the vegetation health, vegetation abundance, vegetation type, and growing conditions under various environments, e.g., soil salinity (Zhang et al., 2011). These indices describe the vegetation cover based on the amount of reflectance in the near-infrared band (NIR) and visible red band (R) regions of the electromagnetic spectrum. Many studies showed that the Nor- malized Difference Vegetation Index (NDVI) was the most popular index among operational users of remote sensing data because of the complexity of other indices (Rondeaux et al., 1996). Vegetation indices are used at all scales ranging from small local projects to global investigation (Walthall et al., 2004). The Normalized Dif- ference Vegetation Index is the most commonly used index to map spatial and temporal variation in vegetation (Tucker, 1979), and it is the best index for a wide range of vegetation densities (Purevdorj et al., 1998). It has been Figure 1. Location map of Wilayat Al-Suwaiq in North used extensively to describe the different vegetation Al-Batinah Governorate, Oman properties, like the amount of green cover, biomass production, green leaf area, and productivity (Alhammadi the highest population density and intensive agriculture and Glenn, 2008). Normalized Difference Vegetation in Al-Batinah North consuming the largest amount of Index values range between -1.0 and 1.0, where values groundwater, which typically is the primary source of of zero and below indicate the presence of water, snow, irrigation water. The most popular crops in Al-Suwaiq ice, or clouds. In contrast, values above 0 indicate the are squash, Rhodes grass, banana, date palm, alfalfa, and presence of vegetation at different densities. Normalized tomato (Al-Aufi et al., 2020). The agricultural season in Difference Vegetation Index values close to 1 (0.8 - 0.9) the study area starts from October to April as it has a indicate high vegetation density (Fu and Burgher, 2015). direct relation with temperature and rainfall patterns. When plants grow under stress like high soil salinity, it The main rainfall season in northern Oman is between causes reduction in chlorophyll and damage to plant cell December and April (MAF and ICBA, 2012). structure. This causes a decrease in near infrared reflectance and increase in visible reflectance (Dunagan et al., Materials and Methods 2007). These differences in reflectance in the two bands give valuable information about vegetation health and Satellite Images Data cover change due to various environmental stresses. In this study, Landsat satellite images for the coastal Cloud-free Landsat 5 TM (Thematic Mapper) and Land- Wilayat of Al-Suwaiq in the North Al-Batinah Governor- sat 8 OLI (Operational Land Imager) satellite images for ate of Oman were used to assess the monthly and annual Al-Suwaiq were downloaded from the USGS Earth Ex- vegetation cover change with the help of the NDVI in- plorer website. In general, Landsat 5 has six reflective dex for the period from 1987 to 2016. Vegetation health bands, while Landsat 8 has nine. Both have bands with and biomass were evaluated for regions related to their a spatial resolution of 30 m in the visible and near-infra- distance from the coastline and soil and water salinity. red regions of the electromagnetic spectrum; however, the spectral resolution of the red and infrared bands of Study Area Landsat 8 is narrower. Table 1 shows the sensor characteristics of both satellites. This study was carried out in the coastal plains of Landsat 8 (OLI) images for the 12 months of the year Wilayat Al-Suwaiq (23°50´58˝N 57°26´19˝E), located in 2015 were used to determine the growing season in the Al- Batinah North Governorate in the Northern part of study area. In addition, a first-order harmonic model Oman (Figure 1). According to PACA (2020), the mean with a linear regression reducer was fit to a time series annual rainfall in Al-Suwaiq is 109 mm, with the months of Landsat 8 (OLI) NDVI images for the years 2013 to of December-March being the wettest and the months 2016 using the Google Earth Engine® platform. This of May-September being the driest. The mean yearly allowed us to determine the months with peak agricul- maximum temperature is 34°C, with a daily maximum ture activity in Al-Suwaiq, and hence, to determine the exceeding 49 °C during the summer months, while the best month to be used for the annual changes detection. mean minimum annual temperature is 22°C. Al-Suwaiq Table 2 provides details of the selected images used to covers an area of approximately 1,000 km² with a total detect the monthly change in vegetation biomass during cultivated land of 80 km². Moreover, a study was done the growing season in the study area from 1987 to 2016. by Choudri et al., (2015) and found that Al-Suwaiq had

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Table 1. Sensor characteristics of Landsat 5 (TM) and Landsat 8 (OLI) satellites

Spatial Repeat Satellite/ Band Spectral Radiometric Band Name Resolution Cycle Sensor Number Range (µm) Resolution (m) (Days) 1 Blue 0.45 - 0.52 30 2 Green 0.52 - 0.60 30 3 Red 0.63 - 0.69 30 Landsat 5 (TM) 4 Near-Infrared 0.76 - 0.90 30 8 bits 16 5 Shortwave Infrared 1 1.55 - 1.75 30 6 Thermal Infrared 10.40 - 12.50 120 7 Shortwave Infrared 2 2.08 – 2.35 30 1 Coastal Aerosol 0.43 - 0.45 30 2 Blue 0.45 - 0.51 30 3 Green 0.53 - 0.59 30 4 Red 0.64 - 0.67 30 5 Near-Infrared 0.85 - 0.88 30 Landsat 8 (OLI) 6 Shortwave Infrared 1 1.57 - 1.65 30 12 scaled to 16 16 7 Shortwave Infrared 2 2.11 - 2.29 30 8 Panchromatic 0.50 - 0.68 15 9 Cirrus 1.36 - 1.38 30 10 Thermal Infrared 1 10.6 - 11.19 100 11 Thermal Infrared 2 11.5 - 12.51 100 Source: https://landsat.gsfc.nasa.gov/

Image Preprocessing The threshold for separating vegetation from non-vegetation was carefully determined with the aid of Image preprocessing is a crucial step to improve image high-resolution images from Google Earth® and ground quality and increase accuracy (Munyati, 2000). The im- truth information. After careful examination and based age preprocessing includes geometric and atmospheric on Holben (1986), vegetation cover based on NDVI val- corrections that reduce and eliminates errors. Image ues were divided into three classes (Table 3). geometric correction is the process of precisely match- ing the image’s projection to a specific projection surface Vegetation Change Detection or shape (Hyyppa et al., 2000). The downloaded images Change detection is defined as the process of identifying were geo-rectified to the Universal Transverse Mercator differences in the state of an object by quantifying tem- (UTM) coordinate system with the datum World Geo- poral effects (Singh, 1989). According to Singh (1989), detic System (WGS) 1984 and zone 40 north. change detection can be used for various purposes such The atmosphere, on the other hand, can have a criti- as land utilization analysis, vegetation cover change, ob- cal impact on the electromagnetic energy sensed by the serving deforestation, crop diseases, stress detection, imaging system detectors (Chavez, 1996), changing its and disaster monitoring. spectral distribution and introducing some skylight into The temporal changes in vegetation were detected the sensor field-of-view (Gilabert et al., 1994). These -im and quantified using the raster calculator in ArcMap® ages were atmospherically corrected to convert digital 10.1. The classified NDVI raster images produced in the number values into surface reflectance using the AT- previous step for the years 1988, 1999, and 2016, the COR ground reflectance workflow in the PCI Geomat- ® month of February (Table 2), were subtracted consecu- ica software. tively to detect and quantify spatial vegetation changes Vegetation Cover Measurement between these periods. The vegetation cover change was evaluated using the Vegetation Cover Change with Distance from Normalized Difference Vegetation Index (NDVI), which the Coastline utilizes the red and near-infrared wavelengths to gener- According to (MAF and ICBA, 2012), between 1994 ate single-band images (Tucker, 1979) and 2004, there was a significant change in groundwater NDVI = (NIR-RED) / (NIR+RED) (1) electric conductivity (EC) in the monitoring wells locat-

Research Paper 3 Spatial and Temporal Assessment of Vegetation Cover in Al- Suwaiq Using Satellite Images Analysis

Table 2. Monthly Landsat 8 (OLI) images used for monthly detection change

Image Year Day/Month Satellite Path Row

1 1987 8-October Landsat 5(TM) 159 43 2 1987 28-December Landsat 5(TM) 158 44 3 1988 5-February Landsat 5(TM) 159 43 4 1988 1-March Landsat 5(TM) 158 44 5 1994 20-October Landsat 5(TM) 158 44 6 1994 7-December Landsat 5(TM) 158 44 7 1995 16-February Landsat 5(TM) 159 43 8 1995 29-March Landsat 5(TM) 158 44 9 1996 16-October Landsat 5(TM) 159 43 10 1996 19-December Landsat 5(TM) 159 43 11 1997 21-February Landsat 5(TM) 159 43 12 1997 2-March Landsat 5(TM) 158 44 13 1998 22-October Landsat 5(TM) 159 43 14 1998 2-December Landsat 5(TM) 158 44 15 1999 20-February Landsat 5(TM) 158 44 16 1999 31-March Landsat 5(TM) 159 43 17 2014 18-October Landsat 8 (OLI) 159 43 18 2014 5-December Landsat 8 (OLI) 159 43 19 2015 16-February Landsat 8 (OLI) 158 44 20 2015 4-March Landsat 8 (OLI) 158 44 21 2015 5-October Landsat 8 (OLI) 159 43 22 2015 24-December Landsat 8 (OLI) 159 43 23 2016 19-February Landsat 8 (OLI) 158 44 24 2016 13-March Landsat 8 (OLI) 159 43 Source: https://earthexplorer.usgs.gov/ ed approximately 5 km from the coastal area of Al-Bati- nah. Therefore, the study area was divided into two distance from coastline classes to monitor and quantify the temporal vegetation cover changes with this distance. A buffer tool in ArcMap® 10.1 was utilized to divide the area into a 0-3 km (North) and 3-6 km (South) distance from the coastline. Soil and Water Sampling and Laboratory Anal- ysis Soil and water samples were collected during the cultivated season in Al-Suwaiq in March 2016. Sixty soil samples were collected randomly from 30 different farm locations making sure the samples uniformly cover the study area from the coast to 9 km inland (~ 23,361 hectares) (Figure 2). During soil sampling, composite soil Figure 2. Soil and water sampling sites. samples comprised of three subsamples of surface (0- 10cm deep) and subsurface (10-20 cm deep) soils were collected in each farm location. Groundwater samples soil paste. The soil texture was determined using the hy- were collected from 36 wells located in the same fields drometer method based on Stoke’s law, which states that where the soil samples were collected. particles of different sizes will settle out of suspension at Soil and water samples were transferred to the labora- different rates over time (Bouyoucos, 1962). tory where the soil was dried and sieved. The soil pH and Water pH and electrical conductivity were measured electrical conductivity were measured from a saturated directly in the solution. The sodicity of water, which

4 SQU Journal of Agricultural and Marine Sciences, 2021, Volume 26, Issue 1 Al-Aufi, Al-Wardy, Choudri, Ahmed, Al-Rawas, Al-Mulla

Table 3. Vegetation classes based on NDVI Table 4. Soil salinity and pH in surface and subsurface soils

EC (dS/m) pH NDVI Class Soil depth Mean Max Min Mean Max Min Surface 0.21 – 0.33 low green-leaf-vegetation 7.35 34.90 0.84 7.70 8.10 6.90 (0-10 cm) 0.33 – 0.67 moderate green-leaf-vegetation Subsurface 5.16 20.10 1.09 7.63 8.10 7.00 0.67 – 1.00 high green-leaf-vegetation (10-20 cm) promotes soil dispersion and causes reduced hydraulic classified as non-saline (0-2 dS/m), 38% as slightly saline, conductivity and aeration, was determined by analyzing 18% as moderately saline (4-8 dS/m), 16% as strongly sa- for Na+, Ca2+, and Mg2+ (expressed in meq/L) in water line (8-16 dS/m), and 11% as very strongly saline (>16 and calculating the sodium adsorption ratio (SAR) as dS/m). follows: Spatial interpolation of soil salinity shows that surface SAR = Na / √ [(Ca + Mg) / 2] (2) and subsurface soil salinity is higher in the agricultural Spatial Interpolation farms closer to the coastline (Figures 4 and 5). This was very much related to the irrigation water quality, as it Spatial interpolation is extensively used in soil scienc- can be seen from the groundwater salinity maps. Inten- es to estimate the spatial pattern of various soil chem- sive agricultural activities closer to the coastline resulted ical properties. According to (Omran, 2012; Mehdi et in excessive groundwater pumping leading to intrusion al., 2013; Bhunia et al., 2018), the kriging interpolation, and the salinization of groundwater (Zekri, 2008). The which takes into consideration the spatial autocorrela- majority of farms farther from the coastline are non-sa- tion of the measured sampled points with distance, is line to slightly saline (< 4 dS/m). Additionally, surface the best method to estimate the spatial distribution of soils were found to be more saline than subsurface soils soil organic carbon, soil EC, and soil pH. as a result of salt accumulation at the surface as the irri- In this study, ordinary kriging was used to map the gation water evaporates (Sommerfeldt and Rapp, 1982). pattern of soil and water salinity in the area. Spherical, Non-saline to slightly saline surface soils covered exponential, and Gaussian models were used to fit the 63% of the mapped agricultural land in the study area. log-normally distributed soil and water EC data. The In comparison, 30% of the area was moderately saline, Gaussian model was found to have the smallest root 7% was strongly saline, and only 1% of agricultural land mean square error, and, hence, was used to predict soil was very strongly saline. On the other hand, non-saline and water salinity distribution. Although the number of to slightly saline subsurface soils covered 76% of the ag- samples was relatively small for a smooth spatial inter- ricultural land in the study area, while 19.2% was moder- polation, the samples were well distributed, and studies ately saline, 3.6 % was strongly saline, and only 0.3% was have shown that ordinary kriging can perform well for very strongly saline. interpolating soil properties when the number of data Water Analysis is limited (Schloeder et al., 2001). A complete flowchart routine of methodology used is illustrated in Figure 3. Table 5 shows the analysis results of groundwater samples collected from the wells in the farms. According Results and Discussion to the FAO water salinity classification (Rhoades et al., 1992), 3% of water samples were non-saline (< 0.7 dS/m), Soil Analysis 54% were slightly saline (0.7 – 2.0 dS/m), 37% were moderately saline (2 – 10 dS/m), and 6% were highly saline The overall soil texture analysis in the study area indi- (10 – 25 dS/m). The sodium hazard of the groundwater cated that 27% of soils are sand and loamy sand, 35% are used for irrigation was very low as the maximum SAR sandy loam, 30% are silt loam and loam, and only 8% value was 2.1. This means the irrigation water in the are either silty clay, silty clay loam, sandy clay loam, or study area, although saline, does not have any potential clay loam. Generally, the soil texture in the study area is to cause soil dispersion and infiltration problems and to coarse to moderately coarse, which means the soils have high water drainage and very low nutrient and water Table 5. Main chemical properties of groundwater in the holding capacity (MAF and ICBA, 2012). study area Table 4 shows the analysis results of soil samples col- Water properties Mean Max Min lected from the farms. The Food and Agriculture Or- ganization (FAO) classifies soils with EC values greater EC (dS/m) 3.20 19.52 0.50 than 2 dS/m as considered saline (Abrol et al., 1988). pH 7.82 8.4 7.0 According to the FAO soil salinity classification, 17% of the surface soils in the agricultural farms of the study are SAR 1.10 2.10 0.73

Research Paper 5 Spatial and Temporal Assessment of Vegetation Cover in Al- Suwaiq Using Satellite Images Analysis

Figure 3. Flowchart of methodology

Figure 4. The pattern of soil salinity in surface soils. Figure 5. The pattern of soil salinity in subsurface soils. aggravate the soil salinity problem further. were also slightly reduced from 67% to 64% and 2.6% to Spatial interpolation of water salinity showed most of 2.2%, respectively. The moderately saline groundwater the groundwater in the study area closer to the coast- area increased from 27% to 33% of the study area. line ranges from moderately to highly saline (Figure 6). Satellite Images Selection for Vegetation Cover According to data collected by the Ministry of Regional Change Znalysis Municipalities and Water Resources from monitoring wells, non-saline groundwater covered about 3.4% of the The vegetation cover in the study area is very hetero- study area in 2010. This area, according to this study, was geneous, including trees, shrubs, and grass of various reduced to 0.8% in 2016. Slightly saline and highly saline species. Therefore, vegetation separation based on their

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produce a unimodal seasonal pattern. It was observed that the low NDVI values occurred towards the end of the growing season during the dry and hot periods (June-September), and the high NDVI values occurred during the rainy and cooler period (December-March). The maximum values (amplitude) according to the fitted model were mainly in the month of February, and the midpoints between the highest and lowest values were in the months of October and March. According to these results, NDVI values for the growing season from October to March were calculated for the different years and compared, while the month of February was used as the base month for change detection.

Figure 6. The pattern of groundwater salinity in the study area. spectral characteristics using medium resolution satellite images from the Landsat mission becomes more complex and very difficult (Xiao and McPherson, 2005). Hence, a threshold for separating vegetation from non-vegetation was carefully determined with the aid of high-resolution images from Google Earth® and ground truth information to be around an NDVI value of 0.21. The best period within the year to study vegetation cover in the study area using NDVI was identified using satellite images for the twelve months of the year 2015. Maximum NDVI, mean above 0 and mean above 0.21, were plotted (Figure 7) and showed that the highest Figure 8. Actual and first harmonic fitted NDVI values for mean and maximum NDVI values occurred in January, the years 2013 to 2016 while the lowest were in July. As the type of vegetation cover varies in the study area. Therefore, a first-order harmonic model was fit to a time series of Landsat 8 Vegetation Cover Change – Temporal (OLI) NDVI images for the years 2013 to 2016 (Figure 8) to smooth the seasonal variations in NDVI values and In general, vegetation cover has significantly changed in North and South Al-Batinah Governorates since the 1980s. Satellite images for the study area showed that the mean NDVI values during the growing season from October to March have increased from 0.29 in 1988 to 0.38 in 2016 (Figure 9). This increase in the mean NDVI was mainly due to the increase in the total cropped area (Figures 10, 11, and 12). According to the Agricultural census carried out by the Ministry of Agriculture and Fisheries, the total cropped area in the whole Wilayat Al-Suwaiq increased from 5835 ha in 1993 to 5887 ha and 11460 ha in 2005 and 2013, respectively (MAF, 1993; 2005; 2013). Moreover, the cropping pattern has considerably changed during this period. There was a sharp increase in the cropped area of Rhodesgrass and Squash from 2005 to 2013. The total cropped area increased from about 1080 ha to 2500 ha and from 38 ha to 4315 ha for Rhodesgrass and Squash, respectively (Al-Aufi, et Figure 7. Maximum, mean above zero, and mean above al. 2020). However, there was a decrease in the cropped 0.21 NDVI values for the twelve months of the year 2015 area for the same period for Date palms and alfalfa from 1865 ha to 1222 ha and 372 ha to 207 ha, respectively.

Research Paper 7 Spatial and Temporal Assessment of Vegetation Cover in Al- Suwaiq Using Satellite Images Analysis

In addition, ground-truthing was carried out and The analysis of the different NDVI classes (Figure 13) showed that, in 2016, out of the 14 locations showing in the study area showed that there was a slight increase high NDVI values (0.67-0.86), 12 were growing Rhodes- in the pixel counts for the lower class of 0.21-0.33, and grass and one each for banana trees and alfalfa. As for hence a small rise in the vegetation area covered by this sites showing moderate NDVI values (0.33-0.67), 13 class. The vegetation cover area for the lowest class in- locations were visited where five were growing Rhodes- creased from 1861 ha in 1988 to 2915 ha and 2755 ha, for grass, and the rest was a mixture of vegetable and field the years 1999 and 2016, respectively (Table 6). The mean crops with mango and date palm trees. The changes in NDVI value, however, remained constant at around 0.26. the NDVI values for the Rhodesgrass between high and The pixel counts for the middle class of 0.33-0.67 has in- moderate might be attributed to various factors such as creased considerably across the class range from 1988 to the growth stage, soil fertilization, or poor management. 2016, and the vegetation cover area increased more than The lower NDVI (0.21-0.33) sites mainly represented na- six folds from 725 ha in 1988 to 4565 ha in 2016. The tive shrubs and trees and the invasive Prosopis juliflora; mean NDVI value has also increased from 0.40 to 0.48 however, few of these sites were also found to grow veg- for the same period of the middle class. The largest in- etables on smaller scales. crease in pixel counts, and hence vegetation cover area,

Figure 9. Mean NDVI during the growing season from Figure 11. Vegetation cover classification in February 1988 to 2016 1999

Figure 10. Vegetation cover classification in February Figure 12. Vegetation cover classification in February 1988 2016

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Figure 13. Figure 13. The difference in pixel counts of the three NDVI classes, (a) 0.21-0.33, (b) 0.33-0.67, (c) 0.67-0.86, from 1988 to 2016. The spread of this data set is described by the first and third quartiles, the median, and the 1.5*interquartile range (IQR). was for the highest class of 0.67-0.86 and for the whole per year (MAF, 2019). This can only exacerbate the sea- class range. The vegetation cover area had increased 72 water intrusion problem, resulting in more salinization folds from a mere 10 ha in 1988 to 719 ha in 2016. of groundwater and, as a result, a more substantial loss This shows that with the advent of technology, there of agricultural farms closer to the coastline. was a large expansion in agricultural activities and the Vegetation Cover Change – Spatial cultivated area. The use of modern irrigation systems in Al-Suwaiq has increased to 78% in the year 2013 (Al-Au- ArcMap® 10.1 was used to show the difference in spa- fi et al., 2020). However, as it was noted from field vis- tial vegetation cover change in the study area between its to sites of high NDVI values being mainly cultivated 1988 and 1999, and 1999 and 2016 NDVI images. This with Rhodesgrass, the large surge in the middle and high differencing allowed to identify the sites where a posi- classes means greater pressure on the water resources tive (increase) or a negative (decrease) change in vegeta- in the study area. Each hectare cultivated with Rhodes- tion cover occurred. Figures 14 and 15 show a site-spe- grass can consume up to 48,000 cubic meters of water cific positive and negative change. Most of the positive

Table 6. NDVI mean and median, and corresponding area, for each class during the study period

1988 1999 2016

0.21 0.33 0.67 0.21 0.33 0.67 0.21 0.33 0.67 Class / NDVI ------0.33 0.67 0.86 0.33 0.67 0.86 0.33 0.67 0.86 Mean 0.26 0.40 0.70 0.27 0.42 0.69 0.26 0.48 0.72 Median 0.26 0.38 0.69 0.26 0.40 0.69 0.26 0.47 0.72 Area (ha) 1861 725 10 2915 2442 58 2755 4565 719

Research Paper 9 Spatial and Temporal Assessment of Vegetation Cover in Al- Suwaiq Using Satellite Images Analysis

Figure 14. NDVI differences between February 1988 and Figure 15. NDVI differences between February 1999 and February 1999 February 2016 change in vegetation cover occurred farther from the coastline, whereas the negative change occurred closer to the coastline. However, in both periods, there was a more positive change in vegetation cover than negative. For the period between 1988 and 1999, there was an increase in vegetation cover by 1798 ha, mainly south of the main highway (3-6 km from the coastline), and a decrease of 350 ha north of the main highway closer to the coastline (0-3 km from the coastline). These losses in vegetation cover in 1999 account for about 14% of the total vegetation that was present in 1988. As for the period between 1999 and 2016, there was an additional increase in vegetation cover by 2843 ha and the reduction of an additional 1157 ha. These losses in vegetation cover in 2016 account for about 31% of the total vegetation that was present in 1999. The difference in vegetation cover area between 1988, 1999, and 2016 is summarized Figure 16. Vegetation cover change with water salinity in Table 7.

Table 7. Change in vegetation cover in hectares and percentage of the total study area for the periods between 1988 – 1999, and 1999 - 2016 1988 -1999 1999 -2016 Class Percent- Percent- Area(ha) Area(ha) age (%) age (%) Decrease in 350 1.5 1157 5.0 vegetation

No change in 21212 90.8 19361 82.9 vegetation Increase in 1798 7.7 2843 12.2 vegetation

The decline in the vegetation cover is mainly attributed to the deterioration in water quality. Figure 16 shows that most of the negative changes in vegetation cover occurred in areas that are affected by high groundwater sa- Figure 17. Vegetation cover change with soil salinity linity, mainly from 2 to 25 dS/m. This decline coincides

10 SQU Journal of Agricultural and Marine Sciences, 2021, Volume 26, Issue 1 Al-Aufi, Al-Wardy, Choudri, Ahmed, Al-Rawas, Al-Mulla

mostly in the same areas with high surface soil salinity, change on the eastern coast of the United Arab Emirates between 4 and 32 dS/m (Figure 17). On the other hand, using SAVI. International Journal of Remote Sensing most positive changes, although varying in areas of dif- 29(6): 1745-1765. ferent soil salinity, occurred in areas with low ground- Bhunia GS, Shit PK, Maiti R. (2018). Comparison of water salinity, indicating the primary role played by the GIS-based interpolation methods for spatial distri- water quality in vegetation cover change rather than soil bution of soil organic carbon (SOC). Journal of the salinity. Saudi Society of Agricultural Sciences 17(2): 114-126. Bouyoucos GJ. (1962). Hydrometer method improved Conclusion for making particle size analysis of soils. Agronomy Making use of remotely sensed available data to moni- Journal 54:464-465. tor spatial and temporal changes in the vegetation cover, Chavez PS. (1996). Image-based atmospheric correc- especially in areas under environmental pressures such tions-revisited and improved. Photogrammetric En- as soil and water salinity, allows for the sustainable man- gineering and Remote Sensing 62(9): 1025-1035. agement and planning of these lands. This study utilized Choudri BS, Baawain M, Ahmed M, Al-Sidairi A, the Landsat satellite images to perform vegetation cov- Al-Nadabi H. (2015). Relative vulnerability of coastal er analysis from 1988 to 2016 in Wilayat Al-Suwaiq in wilayats to development: a study of Al-Batinah North, North Al-Batinah Governorate using the Normalized Oman. Journal of Coastal Conservation 19(1): 51-57. Difference Vegetation Index in conjunction with field Dunagan SC, Gilmore MS, Varekamp JC. (2007). Effects study in the years 2015 and 2016. The results showed of mercury on visible/near infrared reflectance spec- that vegetation cover has significantly changed in the tra of mustard spinach plants (Brassica rapa P.). En- study area, increasing in the area from 2600 ha in 1988 vironmental Pollution 148(1): 301-311.Fu B, Burgher to more than 8000 ha in 2016. This increase has mainly I. (2015). Riparian vegetation NDVI dynamics and its occurred farther (3-6 km) from the coastline, while areas relationship with climate, surface water and ground- closer to the coastline (0-3 km) have seen a decrease in water. Journal of Arid Environments 113: 59-68. vegetation cover. As the analysis has shown, 2.2 % and 33% of the study area is covered by highly and moder- Gilabert M, Conese C, Maselli F. (1994). An atmospher- ately saline groundwater, respectively, mainly existing ic correction method for the automatic retrieval of closer to the coastline and must have impacted the veg- surface reflectances from TM images. International etation cover in these areas negatively. This study also Journal of Remote Sensing 15(10): 2065-2086. showed a surge in the vegetation cover falling within the Holben BN. (1986). Characteristics of maximum-value moderate (0.33-0.67), and more importantly, the high composite images from temporal AVHRR data. In- class (0.67-0.86) NDVI values. This is indicative, accord- ternational Journal of Remote Sensing 7(11): 1417- ing to field visits, of an increase in the cropped area of 1434. Rhodesgrass known for its high consumption of water, Hyyppa J, Hyyppä H, Inkinen M, Engdahl M, Linko S, posing a great challenge for the future planning of the Zhu YH. (2000). Accuracy comparison of various re- agricultural activities in the area and the management of mote sensing data sources in the retrieval of forest water resources. stand attributes. Forest Ecology and Management 128(1): 109-120 References MAF. (1993). Agriculture census report. Oman: Minis- Abrol IP, Yadav JSP, Massoud FI. (1988). Salt-affected try of Agriculture and Fisheries. 1992/1993 soils and their management. FAO Soils Bulletin 39. MAF. (2005). Agriculture census report. Oman: Minis- Food and Agriculture Organization of the United Na- try of Agriculture and Fisheries. 2004/2005 tions. Rome, Italy. 131pp. MAF. (2013). Agriculture census report. Oman: Minis- Al-Aufi K, Al-Wardy M, Choudri BS, Ahmed M. (2020). try of Agricultural and Fisheries. 2012/2013 Analysis of agricultural cultivation trend: A shifting MAF. (2019). https://www.maf.gov.om/MediaCenter/ scenario in a coastal wilayat, Oman. Environment, NewsDetails/12663# (accessed July 14,2020) Development and Sustainability 22: 2685-2698. MAF, ICBA. (2012). Oman Salinity Strategy, Annex Aly AA, Al-Omran AM, Sallam AS, Al-Wabel MI, 1:Assessment of Salinity Problem. Muscat, Sultanate Al-Shayaa MS. (2016). Vegetation cover change de- of Oman. 165pp. tection and assessment in arid environment using Mehdi S, Ghani S, Khalid M, Sheikh A, Rasheed S, Ajmal multi-temporal remote sensing images and ecosys- M, Ashraf A. 2013. Spatial variability mapping of soil tem management approach. Solid Earth 7: 713-725. EC in agricultural field of Punjab province (Pakistan) Alhammadi M, Glenn E. (2008). Detecting date palm using Geographic Information Techniques. Interna- trees health and vegetation greenness tional Journal of Scientific & Engineering Research

Research Paper 11 Spatial and Temporal Assessment of Vegetation Cover in Al- Suwaiq Using Satellite Images Analysis

4(11): 325-338. Journal of Remote Sensing 10(6): 989-1003. Munyati C. (2000). Wetland change detection on the Sommerfeldt T, Rapp E. (1982). Management of saline Kafue Flats, Zambia, by classification of a multitem- soils. Canada Department of Agriculture. Ottawa, poral remote sensing image dataset. International Ontario. Publication 1642E. Journal of Remote Sensing 21(9): 1787-1806. Tucker C J. (1979). Red and photographic infrared lin- Omran ESE. (2012). Improving the prediction accuracy ear combinations for monitoring vegetation. Remote of soil mapping through geostatistics. International Sensing of Environment 8(2): 127-150. Journal of Geosciences 3(3): 574-590. Walthall C, Dulaney W, Anderson M, Norman J, Fang Public Authority of Civil Aviation (PACA). (2020). H, Liang S. (2004). A comparison of empirical and http://www.met.gov.om/opencms/export/sites/de- neural network approaches for estimating corn and fault/dgman/en/weather-chart/historical-data/in- soybean leaf area index from Landsat ETM+ imagery. dex.html (accessed July 16, 2020) Remote Sensing of Environment 92(4): 465-474. Purevdorj T, Tateishi R, Ishiyama T, Honda, Y. (1998). Wiegand C, Rhoades J, Escobar D, Everitt J. (1994). Pho- Relationships between percent vegetation cover and tographic and videographic observations for deter- vegetation indices. International Journal of Remote mining and mapping the response of cotton to soil Sensing 19(18): 3519-3535. salinity. Remote Sensing of Environment 49(3): 212- Rhoades JD, Kandiah A, Mashali AM. (1992). The use of 223. saline waters for crop production. FAO Irrigation and Xiao Q, McPherson EG. (2005). Tree health mapping Drainage Paper 48. Food and Agriculture Organiza- with multispectral remote sensing data at UC Davis, tion of the United Nations. Rome, Italy. 133pp California. Urban Ecosystems 8(3-4): 349-361. Rondeaux G, Steven M, Baret F. (1996). Optimization of Zekri S. (2008). Using economic incentives and regu- soil-adjusted vegetation indices. Remote Sensing of lations to reduce seawater intrusion in the Batinah Environment 55(2): 95-107. coastal area of Oman. Agricultural Water Manage- Schloeder CA, Zimmerman NE, Jacobs MJ. (2001). ment 95(3): 243-252. Comparison of methods for interpolating soil prop- Zhang TT, Zeng SL, Gao Y, Ouyang ZT, Li B, Fang CM, erties using limited data. Soil Science Society of Zhao B. (2011). Using hyperspectral vegetation indi- America Journal 65:470–479 ces as a proxy to monitor soil salinity. Ecological In- Singh A. (1989). Review article digital change detection dicators 11(6): 1552-1562. techniques using remotely-sensed data. International

12 SQU Journal of Agricultural and Marine Sciences, 2021, Volume 26, Issue 1 Journal of Agricultural and Marine Sciences 2021, 26(1): 13–20 DOI: 10.24200/jams.vol26iss1pp13-20 Reveived 03 May 2020 Accepted 16 Nov 2020 Research Paper Effect of Storage Conditions on Postharvest Quality of Tomatoes: A Case Study at Market-Level

Mai Al-Dairi, Pankaj B. Pathare*, Adil Al-Mahdouri

أتثري ظروف التخزين على جودة الطماطم بعد احلصاد: دراسة حالة على مستوى السوق مي الدايري، ابنكاج ابثري*، عادل احملذوري

Abstract. Postharvest loss is one of the main obstacles for ensuring food security in Oman as it leads towards reduced fresh produce quantity, quality and market value. The aim of this study was to determine the postharvest losses due to quality reduction in fresh produce of tomato during storage at market level in Oman. This paper consisted of two separate studies. Firstly, a semi-structure survey was conducted to collect the data from the market vendors. Secondly, fresh tomatoes were also purchased from the market and were stored in the laboratory at 10oC and 22oC for 12 days. All data were analyzed using SPSS statistical software. The results of the survey showed that 35% of respondents suggested that the color and texture are the most important quality attributes attracted by the consumers. Two days period was the best duration to store fresh produce in the current market. About 55% of the respondents mentioned that the nature of the produce was the most important factor causing postharvest losses along the supply chain. The results of the experiments showed a significant (p<0.05) changes of color attributes such as lightness (L*), redness or greenness (a*), total color change (∆E), weight loss and firmness during 12 days at both temperature conditions. However, no significant impact of both factors on yellowness or blueness (b*), chroma, hue and total soluble solid (TSS) values was observed. This study indicated high changes in weight loss, lightness, redness, total color change and firmness in tomato stored at 22°C. The lower was the lightness (4.96) and firmness (11.18 N) and the greater was the redness (12.22) and weight loss (16.6%), caused the greater the rejection by the customers of the tomato at market level. Accordingly, storage temperature played a critical role on the improvement and development of tomato and any perishable fresh produce along the supply chain. Keywords: Color, market, postharvest losses, quality, texture, tomato املســتخلص:تعترب خســارة مــا بعــد احلصــاد إحــدى العقبــات الرئيســية أمــام ضمــان األمــن الغذائــي يف ســلطنة عمــان ألهنــا تــؤدي إىل اخنفــاض كميــة املنتجــات الطازجــة وجودهتــا وقيمتهــا الســوقية. كان اهلــدف مــن هــذه الدراســة هــو حتديــد خســائر مــا بعــد احلصــاد بســبب اخنفــاض جــودة املنتجــات الطازجــة مــن الطماطــم أثنــاء التخزيــن علــى مســتوى الســوق يف عمــان. تتألــف هــذه الورقــة مــن دراســتي منفصلتــن. اشــتملت األوىل علــى إجــراء مســح ميــداين شــبه هيكلــي جلمــع البيــاانت مــن ابئعــي الســوق. واشــتملت الدراســة الثانيــة علــى مجــع البيــاانت املخربيــة علــى نــوع مــن الطماطــمالطازجــة احملليــة، حيــث مت ختزينهــا يف املختــرب عنــد 10 درجــة مئويــة و 22 درجــة مئويــة ملــدة 12 ًــا.مت يومحتليــل مجيــع البيــاانت ابســتخدام برانمــج احلزمــة اإلحصائيــة للعلوم اإلجتماعية ) (. SPSSوأظهرت نتائج املســح امليداين أن 35٪ من املســتجيبي أشــاروا إىل أن اللون وامللمس مها أهم مسات اجلودة اليت جتذب املســتهلكي. وقــد كانــت فــرة التخزيــن املفضلــة للمنتجــات الطازجــة يف الســوق هــي يومــان. ذكــر حــوايل ٪55 مــن املســتجيبي أن طبيعــة املنتــج كانــت العامــل األكثــر أمهيــة يف حــدوث خســائر مــا بعــد احلصــاد علــى طــول سلســلة التوريــد. أظهــرت نتائــج التجــارب تغــ ًريا مؤثــراً )p> ( 0.05يف مســات اللــون مثــل اخلفــة )* (، Lاإلمحــرار أو اإلخضــرار )*a(، تغــري اللــون الكلــي )E∆(، فقــدان الــوزن و الصلبــة خــال 12 يــوم يف مجيــع درجــات حــرارة التخزيــن. ومــع ذلــك ، مل يلحــظ أي أتثــري كبــري لــكل العاملــن علــى اإلصفــرار أو اإلزرقــاق )*b(، صفــاء اللــون، تشــبع اللــون وقيــم املــواد الصلبــة الذائبــة الكليــة )TSS(. أشــارت هــذه الدراســة إىل حــدوث تغــريات كبــ ة يفري فقــدان الــوزن واخلفــة، واالمحــرار، وتغــري اللــون الكلــي وثبــات الطماطــم املخزنــة عنــد 22 درجــة مئويــة. كلمــا قلــت اخلفــة )4.96( و الصلبــة )11.18 نيوتــن( و أزداد االمحــرار )12.22( وفقــدان الــوزن )16.6٪( ،حيــث زاد رفــض الزابئــن للطماطــم علــى مســتوى الســوق. ًوفقــا لذلــك ، تلعــب درجــة حــرارة التخزيــن ًدورا ًمهمــا يف حتســن الطماطــم وأي منتجــات طازجــة قابلــة للتلــف علــى طــول سلســلة التوريــد. الكلمات املفتاحية: اللون، السوق، خسائر ما بعد احلصاد، اجلودة، الصلبة، الطماطم. Introduction unprofitable and useless (Sarma, 2018). Postharvest losses of fresh produce can be encountered during har- lobally, One-third of the total fresh food pro- vesting, storing, handling, packaging, transporting and duced is lost during food supply chain before marketing operations (Sibomana et al., 2016). The na- reaching to the consumers (Gautam et al., 2017; ture of fresh produce is one of the main causes of post- GMunhuewyi, 2012). Despite all of the benefits derived harvest losses along the whole value chain as they are from any fresh produce, postharvest losses make them highly perishable (Parfitt et al., 2010), respire and live even after harvesting (Kader and Rolle, 2004). Improper Pankaj B. Pathare* ( ) [email protected]; [email protected], Department of Soils, Water and Agricultural Engineering, College of harvesting method and equipment, inadequate storage Agricultural & Marine Sciences, Sultan Qaboos University, Oman and packaging facilities are the factors contributing to the postharvest losses in fresh produce (Chebanga et al., Effect of Storage Conditions on Postharvest Quality of Tomatoes: A Case Study at Market-Level

2018). Cultural practices (Semida et al., 2019), environ- 2018; Sibomana et al., 2015) with various benefits to hu- mental factors (Singh et al., 2014), poor transportation man body (Arab and Steck, 2000; Bhowmik et al., 2012) services (Caixeta-Filho and Péra, 2018) and improp- like vitamins (A, B and C), amino acids, calcium, copper, er market facilities are other important causes of the sodium (Mandal et al., 2018), antioxidants, lycopene and postharvest losses (Sharma and Singh, 2011). At mar- carotenoids that are responsible for reducing the inci- ket level, the incidence of fresh produce quality losses dence of some chronic and vascular diseases (Arah et and deterioration can occur due to poor management al., 2015; Tadesse et al., 2015). Tomato production can (Sharma and Singh, 2011) and performance of traders, be a source of income (Addo et al., 2015) in most of the processors, producers, retailers and other labors in the developing countries (Arah et al., 2015; Sarma, 2018). marketing system. Absence of technical awareness and The quality of tomato can be recognized predominantly knowledge on postharvest losses (Sarma, 2018), limit- by flavor, texture, color and nutritional value (Kader and ed marketing strategies and information (Rolle, 2006), Rolle, 2004). Due to the current postharvest problems, and lack of efficient communication between produc- losses in tomato could reach to 50% worldwide (Addo et ers and buyers are other factors leading to postharvest al., 2015). damage on fresh produce at market level (Arah et al., During marketing, temperature is the main factor 2015). Moreover, losses during marketing can occur due that impacts tomato quality as it directly influences the to non-existence of adequate postharvest infrastructure, rate of losses. Proper control of temperature condition is technologies (Aujla et al., 2011) and sanitation, packag- the most suitable way to retain the quality of fresh pro- ing, loading, unloading and storage (Kader and Rolle, duce during the whole supply chain (Arah et al., 2015). 2004). Additionally, inappropriate storage facilities can Basically, temperature can influence tomato color, firm- cause high quantitative losses compared to the qualita- ness and flavor (Tadesse et al., 2015). Storage below 10°C tive losses in fresh produce (Ayomide et al., 2019). Sub- cause poor color development of tomato (Khairi et al., sequently, negative impacts on several parameters such 2015), however, storage at 20°C and 30°C reduce tomato us nutritional status, consumer acceptance and income firmness and weight loss (Tadesse et al., 2015). Storing are affected (Sarma, 2018; Seyoum and Woldetsadik, tomato at low temperature can decrease the metabolic 2004). Postharvest losses in fresh produce at market lev- activity of tomato. High increase in temperature can el in Oman are estimated between 3-19 % (Opara, 2003). elevate transpiration rate, respiration rate and ethylene Tomato (Solanum lycopersicum) is one of the ma- production rate. However, chilling temperature can jor and popular fresh produce in the world (Costa and reduce tomato quality due to the incidence of chilling Heuvelink, 2018; Guan et al., 2018; Sarma and Ali, 2019). injuries (Atanda et al., 2011). Most of the studies report- Statistics display that the production of tomatoes in Sul- ed that storage temperature around 10°C is the most tanate of Oman ranked first among other vegetables like appropriate storage temperature condition for main- onions (Allium cepa) (Ona, 2017), cucumbers (Cucumis taining the quality (Cantwell et al., 2009; Khairi et al., sativus) and potatoes (Solanum tuberosum) which reach 2015; Ponce-Valadez et al., 2016) and delaying softening up to 199,132 tons (886 ha cultivated area) in 2018 after of tomato (Ayomide et al., 2019). Relative humidity (RH) it was 39,586 tons (2532 ha cultivated area) in 2000 (Fig- is another important factor during storage of tomato ure 1) (FAOSTAT, 2020). It is a vital source of nutrients (Ramaswamy, 2014), which can influence its texture and (Ayandiji et al., 2011; Erba et al., 2013), minerals (Sarma, weight loss (El-Ramady et al., 2015). The optimal rela-

Figure 1. Tomato annual production among other vegetables in Oman. (FAOSTAT, 2020)

14 SQU Journal of Agricultural and Marine Sciences, 2021, Volume 26, Issue 1 Al Dairi, Pankaj, Al-Mahdouri

tive humidity values for green and firm ripe tomato are Color value of each tomato sample was measured 85-95% and 90-95%, respectively (Suslow and Cantwell, using a colorimeter (Model: TES 135A, TES Electrical 2009). Application of proper temperature and humidity Corp., Taiwan) which expresses the color values of L* management practices at market level plays a significant (Lightness), a*(redness, greenness) and b*(yellowness, role to reduce postharvest food losses at market level. blueness). The devise was calibrated using a white stan- Therefore, the aim of this study was to determine ven- dard tile (L*=93.90, a*= 3.13, b*= 3.20). Total color dif- dor’s knowledge on postharvest practices and their references, (Eq. 2), chroma (Eq.3) and hue angle in (Eq.4) lated losses at market level and to correlate them with (Pathare et al., 2013) were respectively calculated to local tomato produce quality losses during storage using show color changes (Bal et al., 2011) during 12 days at laboratory experiments. 10°C and 22°C. Materials and Methods

Market survey The study was conducted in the Central Market of Fruits and Vegetables, Muscat, Sultanate of Oman. This market was selected due to its large-scale of sales and availabil- Hand penetrometer (Model: FT 327, EFFEGI, Italy) ity of different fresh produces compared to other mar- was used to determine each tomato firmness by using kets in Muscat. A semi-structure survey was designed the standard method of OECD (2018) at two days in- as a tool for data collection by conducting short inter- terval. Kleinhenz and Bumgarner (2012) procedure was views with the 20 vendors. The questionnaire consists used to identify total soluble solid by using hand-held of formal questions and it was pre-reviewed and tested refractometer calibrated in o Brix at 22ºC. to provide the desired wide-range of responses from the vendors. The purpose of this survey was to determine Data Analysis the vendor’s knowledge about postharvest quality and In order to determine, the effect of storage time and losses in fresh produce. temperature on tomato quality parameters, analysis of Laboratory Experiment variance (ANOVA) was performed by using SPSS 20.0 (International Business Machine Crop., USA) software. About 32 kg of tomatoes were purchased from the market and delivered to Postharvest Laboratory, College of Results and Discussions Agriculture and Marine Sciences at Sultan Qaboos Uni- versity. Tomatoes with no bruising signs, uniform color Survey Analyses and shape were selected to be tested for some quality analysis for total period of 12 days at two days intervals. The analysis of the semi-structure survey of the vendors The tomatoes were stored at 10°C with 85±5% RH and showed that 75% of the participants were (from the age 22°C with 45±5% RH (simulate market storage tempera- of 31-40) and this age is almost appropriate for people to ture). Each storage condition consisted of seven groups sell fruits/vegetables products especially for those who of tomato samples for storage time (temporal) assess- are searching for a job. This is an active age of the com- ment. Each group included five replicates. Tempera- munity who can establish an excellent marketing net- ture/RH prop (Model: TES 13604, TES Electrical Corp., work. Almost, 50% of the vendors were school graduate, Taiwan) was used to measure temperature and relative this helped to facilitate good and rapid understanding humidity. of the respondents to the survey. This also pays the at- Tomato Quality Measurements tention for the vendors to know the most common fresh produce consumed by people and getting more knowl- Electric weight balance (Model: GX.4000, Japan) was edge about postharvest and its related losses. The major- used to weigh each tomato group. The percentage of ity of the respondents were non-Omani (90%) because weight loss in tomato was calculated using the equation Omani farms owners let their labors (from other nation- (Eq. 1) applied by Moneruzzaman et al. (2009): alities) to sell their fruits/vegetables on the market.

Research Paper 15 Effect of Storage Conditions on Postharvest Quality of Tomatoes: A Case Study at Market-Level

Vegetables Vendor’s Observations on Posthar- bient storage condition showed the ability to increase vest Quality, Losses and Practices weight loss of tomato due to high water dehydration (Fagundes et al., 2015), transpiration (Žnidarčič et al., Four of these 20 vendors were from closed markets (re- 2010) and respiration rate (Žnidarčič and Požrl, 2006). tail shops), but the other 16 were from an open markets Furthermore, Ayomide et al. (2019) stated that low rel- (retail shade). The temperature of the closed markets o o ative humidity (45±5%) at 22°C was responsible for the was between 18 C to 23 C. On the other hand, the tem- o reduction of water content in fresh produce leading to perature of the open markets was 32.7 C in the dates of weight loss. Similar findings were recorded by Pinheiro conducting this survey. For consumer preference on a et al. (2013) on the stored fresh tomato. These results specific product, color and texture were having the high- were in agreement with different studies in which a pro- est attention by the consumers for a specific fresh pro- gressive increase was also found in weight loss during duce as suggested by 35% of the vendors compared with storage time at 8°C, 12°C, 20°C for 20 days (Park et al., flavor and money. Generally, color is the most significant 2018), at 34°C for 10 days (Pila et al., 2010) and at room quality preference of any fresh produce (Tadesse et al., temperature, 12°C and 5°C for two weeks (Javanmar- 2015) as well as texture (Batu, 2004) and the availabili- di and Kubota, 2006). These findings were also in -ac ty of undesirable color and texture in any fresh produce cordance with that of Abiso et al. (2015) who reported can consider as a serious problem encountered during high percentage of weight loss in tomato with different the supply chain. About 60% of the vendors are more maturity stages after 10 days storage at room tempera- likely to store their products for two days. However, oth- ture that could be mainly due to respiration and tran- ers prefer to store them for three and five days. Vendors spiration with a minimum loss in tomato stored at cold are storing their products within time that is not exceed- temperature. Overall, low weight loss in tomato at low ing these specific periods due to the lack of ventilated storage temperature can be resulted from the ability of storage utilities (Negasi et al., 2013). High temperature cold stored tomato to affect vapor pressure and increase (Tilahun, 2010) was also one of the reasons that make water retention. vendors storing their products for not more than 5 days Color measurements of this as it was characterized to reduce the quality of fresh pro- Color Measurements: study showed that L* value was significantly (p<0.05) duce as it can reach to 45°C in Oman. Some of the ven- affected by storage time and temperature (Table 2). L* dors were not storing their products as they were selling value decreased from 14.13±1.68 to reach 11.76±0.63 on the whole amount in the same day. There were several day 0 and 12, respectively, at 10°C storage. However, the factors causing postharvest losses along the supply chain reduction was three times higher on tomato stored at as stated by the vendors. For example, 55% of the ven- ambient storage condition as it became 4.96±0.55 in the dors suggested that nature of the product was the most last day of storage. At 12 day of storage, study showed important barrier causing fresh produce losses as they 64.89% reduction on lightness on tomato stored at 22°C are highly perishable (Nath et al., 2018), sensitive (Parfitt compared to only 16.77% at 10°C. This attributed to et al., 2010) and required careful storage, transportation tomato darkening resulted from the synthesis of carot- and handling facilities (Kader, 2013) before they reach enoids (Yahia et al., 2007). to the market. This is followed by marketing problems, improper harvesting and other causes due to infections with 30%, 10% and 5% respectively. Summary of vendor’s respondents on postharvest quality, losses and practices is shown in Table 1.

Table 1. Summary of vegetables vendor’s responses on questionnaire (%)

Consumer preference on Days of storing the products The main barrier of postharvest losses a specific product Texture 35% 2 60% Infection 5% Color 35% 3 20% Improper harvesting 10% Flavor 20% 5 20% Nature of the product 55% Money 10% 7 0% Marketing problems 30%

Tomato Quality Analysis: Experimental Results Similarly, storage days and temperature showed a sta- Weight Loss: The results showed a significant effect tistical difference (p<0.05) with a* value as tomato color (p<0.05) of storage days and temperature on tomato altered from bright green (-) to dark red (+) color (Table weight loss. In the current study, high weight loss was 2). Storage at 22°C decreased a* values of tomato from recorded with 16.6% in tomato stored at 22°C compared -2.19±0.83 on day 0 to 8.02±1.59 and 12.22±0.98 on day to 3.18% losses at 10°C for 12 days storage period. Am- 6 and 12 respectively. In contrast, a* value was increased

16 SQU Journal of Agricultural and Marine Sciences, 2021, Volume 26, Issue 1 Al Dairi, Pankaj, Al-Mahdouri

slowly to reach 1.53±0.51and 5.68±0.72 on day 6 and 12 Firmness: The data showed that firmness of stored to- respectively after it was 2.19±0.83 on day 0 at 10°C. The mato was significantly (P<0.05) affected by storage time a* value increment at 22°C occurred due to ethylene bio- and temperature. In the day last of storage, the highest synthesis (Hatami et al., 2012), synthesis of lycopene and value (49.64 N) was reported in tomato stored at 10°C degradation of chlorophyll (López and Gómez, 2004) while the storage at 22°C reported the lowest value that allowed for the intensification of red color (Wein- (11.18 N) (Table 2). Moisture losses (Lana et al., 2005), gerl and Unuk, 2015). This can also advocate what has degradation of polysaccharide (Teka, 2013) and degra- been recorded by Munhuewyi (2012), where tomato kept dation of tomato cell wall were due to enzymes activa- at ambient condition can provide an ideal environment tion could be the main reason for decreasing firmness for tomato ripening that is categorized with increasing during storage (Hatami et al., 2012). Slow increase of redness compared to cold storage condition. Messina et firmness was shown on tomato firmness stored at 10°C al. (2012) found the same behavior in tomato stored for due to the increment of relative humidity, which had the 7 and 14 days. Regarding storage at cold temperature, ability to slow softening and enhance/retain the firm sta- Guillén et al. (2006) reported similar results on different tus of tomato during storage (Ayomide et al., 2019). The variety of tomato cultivars at 10°C for 28 days. findings of firmness reduction were in agreement with Table 2 presents b* value (mean±sd) at 10°C and 22°C Tigist et al. (2013) who stated storage at 22°C reduced for 12 days storage conditions. There was no significant the firmness of tomatoes. (p>0.05) change on b* value of fresh tomato at both storage conditions during the whole period of storage. Same results of non-significance on b* value were recorded Total Soluble Solids (TSS): Tomato total soluble solid by López and Gómez (2004) during storage. Total col- (TSS) ranged from (4.04 to 4.48) °Brix in this study (Ta- or change ∆E during storage is consider as a result of ble 2). The highest value (4.48 °Brix) was recorded on day changes in L*, a* and b* values. Storage days showed 10 in tomato stored at 10°C where the lowest value (4.04 a significant impact (p<0.05) on color differences ∆E °Brix) was shown on day 6 and 10 in tomato stored at value of tomato stored at 10°C and 22°C. Overall color 22°C. Therefore, the study revealed no statistical differ- differences (∆E) was mostly higher for ambient stored ences (p>0.05) of storage days and temperature on toma- tomato (20.05±4.56) compared to optimum temperature to total soluble solid (TSS). Similarly, Wills and Ku (2002) (7.74±4.07) after 12 days of storage (Table 2). Moreover, experienced the same finding of non-significance after no changes (p>0.05) occurred in chroma and hue values storing tomato for 10 days at ambient room temperature. during 12 days at both storage temperature conditions (Table 2). However, Tadesse et al. (2015) showed a significant differences in chroma and hue stored for 16 days at 4, 20 and 30°C.

Table 2. Quality parameters data of tomato at two storage conditions during12 days of storage. Storage Quality tem- Storage days parameter perature 0 2 4 6 8 10 12 10°C 14.13±1.68 12.39±1.56 13.25±1.07 13.26±1.13 13.36±1.56 11.87±1.75 11.76±0.63 L* 22°C 14.13±1.68 12.37±0.55 9.09±0.72 7.81±0.63 6.34±0.71 5.95±0.75 4.96±0.55 10°C -2.19±0.83 0.45±1.26 1.1±0.15 1.53±0.51 2.7±0.49 3.0±0.63 5.68±0.72 a* 22°C -2.19±0.83 2.64±2.58 5.88±0.63 8.02±1.59 9.15±1.33 10.13±0.73 12.22±0.98 10°C 54.36±4.42 52.40±1.23 54.02±3.36 56.95±4.95 54.52±1.83 54.74±6.68 56.90±2.20 b* 22°C 54.36±4.42 49.22±2.56 44.80±2.68 50.96±1.01 41.72±5.25 41.99±3.10 46.35±6.28 10°C - 5.94±4.02 5.94±3.59 6.12±2.72 6.60±1.03 7.86±2.06 7.74±4.07 ∆E 22°C - 8.42±2.45 13.98±5.33 18.70±10.98 19.14±5.44 19.81±5.65 20.05±4.56 10°C 54.41±4.40 52.41±1.24 54.03±3.36 56.97±4.95 54.59±1.85 54.82±6.65 57.18±2.25 Chroma 22°C 54.41±4.40 49.34±2.53 45.19±2.60 51.60±0.90 42.74±5.05 43.20±2.99 47.94±6.23 10°C -1.53±0.01 0.93±1.38 1.55±0.003 1.54±0.008 1.51±0.007 1.51±0.01 1.47±0.009 Hue 22°C -1.53±0.01 5.27±18.74 7.72±1.28 6.52±1.11 4.65±1.02 4.16±0.51 3.79±0.40 10°C 34.73±3.92 37.08±3.73 41.79±3.83 43.16±2.75 46.89±2.06 48.46±2.55 49.64±2.35 Firmness (N) 22°C 34.73±3.92 32.18±5.30 27.27±6.77 21.78±1.45 20.01±1.08 12.16±1.57 11.18±1.08 10°C 4.12±0.17 4.26±0.23 4.10±0.23 4.42±0.34 4.30±0.18 4.48±0.04 4.34±0.18 TSS (%) 22°C 4.12±0.17 4.08±0.08 4.32±0.44 4.04±0.05 4.16±0.08 4.04±0.05 4.12±0.17

Research Paper 17 Effect of Storage Conditions on Postharvest Quality of Tomatoes: A Case Study at Market-Level

Conclusion Ayomide O, Ajayi O, Ajayi A. (2019). Advances in the development of a tomato postharvest storage system: To- Color and texture of fresh tomato were highly affected wards eradicating postharvest losses. Journal of Phys- by time and storage temperature. This indicated the sig- ics: Conference Series. IOP Publishing, p. 022-064. nificance of these two parameters as they greatly affect Bal L, Kar A, Satya S, Naik S.N. (2011). Kinetics of co- consumer’s acceptance in markets. This agreed what lour change of bamboo shoot slices during micro- had been responded in the questionnaire as most of the wave drying. International Journal of Food Science & vendors suggested that color and texture were the top Technology 46(4): 827-833. consumer’s preference for a specific food product. Sim- ilarly, weight loss, L*and a*, were influenced by storage Batu A. (2004). Determination of acceptable firmness days at 10°C and 22°C. Most of these quality parameters and Colour Values of Tomatoes. Journal of food engi- were almost retained at low temperature (10°C). No sig- neering. 61(3): 471-475. nificant changes were observed for b*, chroma, hue and Bhowmik D, Kumar K, Paswan S, Srivastava S. (2012). To- TSS values at both storage conditions for 12 days stor- mato-A natural medicine and its health benefits. Jour- age. This study indicated that storage temperature was nal of Pharmacognosy and Phytochemistry 1(1): 33-43. one of the vital factors, which required high monitoring Caixeta-Filho J, Péra T. (2018). Post-harvest losses along postharvest supply chain and marketing. during the transportation of grains from farms to aggregation points. International Journal of Logistics Acknowledgement Economics and Globalisation 7(3): 209-247. Cantwell M, Nie X, Hong G. (2009). Impact of storage The authors would like to thanks Sultan Qaboos Uni- conditions on grape tomato quality, 6th ISHS post- versity for funding this study through internal grant harvest symposium, Antalya, Turkey. (IG/AGR/SWAE/19/03). Chebanga F, Mukumbi K, Moses M, Mtaita T. (2018). References Postharvest losses to agricultural product traders in Mutare, Zimbabwe. Journal of Scientific Agriculture Abiso E, Satheesh N, Hailu A. (2015). Effect of storage (2): 26-38. methods and ripening stages on postharvest quality Costa J, and Heuvelink E. 2018. The Global Tomato In- of tomato (Lycopersicom Esculentum Mill) cv. Chali. dustry. CAB International, Oxfordshire, UK. Annals. Food Science and Technology 6(1): 127-137. El-Ramady H, domokos-szabolcsy E, Abdalla N, Taha Addo J, Osei M, Mochiah M, Bonsu K, Choi H, Kim J. H, Fári M. (2015). Postharvest Management of Fruits (2015). Assessment of farmer level postharvest losses and Vegetables Storage, Sustainable Agriculture Re- along the tomato value Chain in three agro-ecological views. Springer International Switzerland, p. 65-152. zones of Ghana. International Journal 2(9): 2311-2476. Erba D, Casiraghi M, Ribas-Agustí A, Cáceres R, Marfà Arab L, Steck S. (2000). Lycopene and cardiovascular O, Castellari M. (2013). Nutritional value of toma- disease. The American Journal of Clinical Nutrition toes (Solanum lycopersicum L.) grown in greenhouse 71(6): 1691S-1695S. by different agronomic techniques. Journal of Food ArahI, Kumah E, Anku E, Amaglo H. (2015). An overview Composition and Analysis 31(2): 245-251. of post-harvest losses in tomato production in Afri- Fagundes C, Moraes K, Pérez-Gago M, Palou L, Mara- ca: Causes and possible prevention strategies. Journal schin M, Monteiro A. (2015). Effect of active modi- of Biology, Agriculture and Healthcare 5(16): 78-88. fied atmosphere and cold storage on the postharvest Atand S, Pessu P, Agoda S, Isong I, Ikotun I. (2011). The quality of cherry tomatoes. Postharvest Biology and concepts and problems of post–harvest food losses Technology. 109: 73-81. in perishable crops. African Journal of Food Science FAOSTAT. 2020. Food and Agriculture Organization 5(11): 603-613. Corporate Statistical Database. FAO, Rome, Italy. Aujla K, Shah N, Ishaq M, Fraooq A. (2011). Postharvest Gautam S, Acedo A, Schreinemachers P, Subedi B. losses and marketing of grapes in Pakistan. Sarhad (2017). Volume and value of postharvest losses: Journal of Agriculture 27(3): 485-490. The case of tomatoes in Nepal. British Food Journal Ayandiji A, Adeniyi O, Omidiji D. (2011). Determinant 119(12): 2547-2558. postharvest losses among tomato farmers in ime- Guan Z, Biswas T, Wu F. (2018). The US Tomato Indus- ko-afon local Government area of Ogun State, Ni- try: An Overview of Production and Trade, EDIS. geria. Global Journal of Science Frontier Research Guillén F, Castillo S, Zapata P, Martínez-Romero D, 11(5): 23-27. Valero D, Serrano M. (2006). Efficacy of 1-MCP treatment in tomato fruit: 2. Effect of cultivar and ripening

18 SQU Journal of Agricultural and Marine Sciences, 2021, Volume 26, Issue 1 Al Dairi, Pankaj, Al-Mahdouri

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20 SQU Journal of Agricultural and Marine Sciences, 2021, Volume 26, Issue 1 Journal of Agricultural and Marine Sciences 2021, 26(1): 21–26 DOI: 10.24200/jams.vol26iss1pp21-26 Reveived 06 July 2020 Accepted 01 Dec 2020 Research Paper Subclinical Mastitis in Camels in Oman: A Pilot Study

Muhammad Nadeem Asi, Waleed Al-Marzooqi, Yasmin ElTahir, Al Ghaly, Al Toobi, Sara Al Raisi, Haytham Ali, Elshafie I. Elshafie, Eugene H. Johnson

ِ ِ ِ إلتهاب الضرع َحتت َّالس ِرير َّ يفي اإلبل يف عمان: د َراسة إِْرتيَاديَّة حممد ندمي عاصي ، وليد املرزوقي ، ايمسني الطاهر ، الغالية الطويب ، سارة الرئيسي ، هيثم علي ، الشفيع إبراهيم الشفيع ، يوجني هاربر جونسون

Abstract. Camels are important and multipurpose animals in many parts of the world including Middle East. Camel milk may harbor different bacteria. Centuries old tradition of consumption of raw camel milk is still a common practice in Oman. This study was carried out to conduct a microbiological analysis of camel milk samples with subclinical mastitis in the region of Muscat, Sultanate of Oman. A total of 61 camel (Camelus dromedarius) milk samples were collected from various animal holdings in and around Muscat. Onsite California Mastitis Test (CMT) revealed 18 (29%) camels positive for subclinical mastitis. Positive milk samples were subjected to routine microbiological workup for bacterial isolation and identification. A total of 7 (47%)Enterobacter cloacae isolates, 4 (27%) Escherichia. coli, 3 (20%) coagulase negative Staphylococci spp. (CNS) and 1 (7%) Micrococcus spp. were identified out of 15 milk samples. Three milk samples did not yield any growth after two repeat attempts. Isolates belonging to Enterobacteriaceae were further subjected to antimicrobial sensitivity testing. All E. cloacae samples 7 (100%) were found to be resistant to penicillin, ampicillin, amoxicillin-clavulanic acid, first generation cephalosporins, and the macrolide group of antibiotics whereas 3 (43%) E. cloacae isolates were found to be intermediately resistant to the phenicol group of antibiotics. All four E. coli (100%) isolates were found resistant to penicillin, ampicillin, amoxicillin-clavulanic acid, first generation cephalosporins, and 2 (50%) showed resistance to macrolides, whereas 1 (25%) isolate was found to be resistant to tetracyclines. In this study, Enterobacteriaceae were the most common group of bacteria isolated from camels with subclinical mastitis. Enterobacter cloacae and E. coli were the predominant organisms. Keywords: Raw camel milk, Enterobacter cloacae, E. coli, resistance املســتخلص تعترب :اإلبــل حيــواانت مهمــة ومتعــددة األغــراض يف أجــزاء كثــرة مــن العــامل مبــا يف ذلــك الشــرق األوســط. قــد حيتــوي حليــب اإلبــل علــى أنــواع خمتلفــة مــن البكتــراي. ال يــزال تقليــد اســتهالك حليــب اإلبــل اخلــام ممارســة شــائعة يف عمــان منــذ قــرون. أجريــت هــذه الدراســة إلجــراء حتليــل ميكروبيولوجــي لعينــات حليــب اإلبــل املصابــة ابلتهــاب الضــرع حتــت َّالس ِــرير َّ يفي منطقــة مســقط ، ســلطنة عمــان. مت مجــع 61 عينــة مــن حليــب اإلبــل )Camelus dromedarius( مــن خمتلــف حيــازات احليــواانت يف مســقط وحوهلــا. أظهــر اختبــار كاليفورنيــا إللتهــاب الضــرع )CMT( أن 18 ) ٪( 29مــن اإلبــل كانــت إجيابيــة لإلصابــة إبلتهــاب ِ الضــرع حتــت الســريري. مت إخضــاع عينــات احلليــب املوجبــة للفحــص امليكروبيولوجــي الروتيــي لعــزل وتعريــف البكتــراي. أظهــرت النتائــج 7 )47٪( عــزالت مــن األَْمعائيَّــةُ ِ ِ ِ ِ امل ْذَرقيَّــة ، 4 )27٪( مــن اإل ْشــريكيَّةُ القولونيَّــة ، 3 ) ٪(20 مــن املكــورات العنقوديــة الســلبية املخثــرة و 1 )7٪( مــن جنــس البكــراي امل َكيـََّــرة مــن أصــل 15 عينــة َ ُ ِ حليــب. ثــالث عينــات مــن احلليــب مل تســفر عــن أي منــو بكتــري بعــد حماولتــني متكررتــني.مت إجــراء إختبــار احلساســيه للعــزالت الــي تنتمــي إىل األَْمعائيَّــات ملضــادات ِ ِ امليكــروابت. أظهــرت النتائــج أن مجيــع عينــات 7 )100٪( األَْمعائيَّ ــةُامل ْذَرق ــة يَّكانــت مقاومــة للبنســلني، األمبيســلني، محــض أموكسيســيلني-كالفوالنيك، اجليــل األول َ ِ ِ مــن السيفالوســبورينات، وجمموعــة املاكروليــد مــن املضــادات احليويــة، بينمــا 3 )43٪( مــن عــزالت األَْمعائيَّ ــةُامل ْذَرقيَّــة ذات مقاومــة متوســطه جملموعــة الفينيكــول مــن املضــادات احليويــة. مت العثــور علــى عــزالت اإلشــريكية القولونيــة األربعــة ) ٪( 100مقاومــة للبنســلني واألمبيســلني َومحــض أموكسيســيلني كالفوالنيــك واجليــل األول مــن ِ السيفالوســبورين و 2 )50٪( مقاومــة للماكروليــدات ، بينمــا وجــدت عزلــة واحــدة )25٪( مقاومــة للتتاســيكلني. يف هــذه الدراســة ، كانــت البكتــراي األَْمعائيَّــةُ هــي اجملموعــة األكثــر شــيوعا مــن البكتــراي املعزولــة مــن اإلبــل املصابــة إبلتهــاب الضــرع حتــت الســريري. كانــت بكــراي األَمعائِيَّــة ُامل ْذرقِيَّــة و ِاإل ْش ِــريكيَّةُ القولونِيَّــة هــي الســائدة. ْ َ َ الكلمات املفتاحية: حليب اإلبل اخلام ، األَمعائِيَّ ةُامل ْذرقِيةَّ ، ِاإل ْش ِريكيَّةُ القولونِيةَّ ، املقاومة. ْ َ َ Introduction world, camel (Camelus dromedaries) is akin to culture and subsistence livelihood in rural areas where camel amels are a mainstay of rural communities is an important source of milk (Barlowska et Al., 2011; in Oman as elsewhere in arid and semi-arid Zibaee et al, 2015), which is generally acclaimed for zones in the Middle East and Africa, by virtue its nutritive and health benefits (Mullaicharam, 2014). Cof their endurance and productive potential under such Moreover, camel’s milk has recently been gaining wider agro-ecological environments. In Oman, as in the Arab consumption and a place in the market of dairy products. Relevant to that is the relatively substantial population Muhammad Nadeem Asi( ) [email protected], Assistant Professor, Department of Animal & Veterinary Sciences, College of Agricultural of camel in Oman, estimated at 273,000 (NCSI, 2019), & Marine Sciences, Sultan Qaboos University, 123 Oman with significant contributions to livelihood of the owners and economy. However, one of the major problems Subclinical Mastitis in Camels in Oman: A Pilot Study impacting camel milk production and health is masti- Materials and Methods tis, though there is lack of reports in Oman. Mastitis, both clinical and subclinical, has been reported in Gulf Study Area countries neighboring Oman, UAE and Saudi Arabia, in addition to Iraq, Kuwait, Pakistan, India, Somalia, Su- In this study, a total of 61 milk samples from healthy dan, Kenya and more (Toroitich et al., 2017). Subclinical she-camels (Camelus dromedaries) located in various mastitis does not seem to show clear clinical signs but holdings in and around Muscat, Sultanate of Oman were pathogenic microorganisms are harbored in intramam- considered. mary tissue and are secreted in the milk. However, milk Ethics Statement from an animal positive for subclinical mastitis may appear normal with normal total somatic cell count. This In this study, verbal consent of camel’s owners was ob- does raise public health concern considering the tradi- tained prior to the collection of milk samples from their tion of consumption of raw and unpasteurized milk in animals. Animals were used just once for milk collection these regions, besides its bearing on camel health and by professional veterinary technologists at the Depart- losses in milk yield. However, unpasteurized milk is not ment of Animal & Veterinary Sciences. This work was recommended for its safety issue. Our literature search not an experimental research on animals and hence ap- indicated that there is lack of studies on subclinical mas- proval by the ethical committee at Sultan Qaboos Uni- titis in camels in Oman. Therefore, the aim of this study versity was not obtained. was to investigate the status of subclinical mastitis by Milk Samples Collection conducting microbiological analysis of milk of camels to ascertain the extent of positive cases. Milk sampling was done by hand stripping just prior to A number of studies investigated subclinical mas- milking using sterile screw caped 50 ml Falcon tubes titis in camel with successful application of California (Kartell S.p.A and Cellstar tubes, Germany). Milk sam- Mastitis Test (CMT) (Saber et al., 2010, Ali et al., 2019). ple (10 mL) was collected from each quarter in a sterile Assessment of milk samples by CMT and somatic cell tube and labeled as per guidelines. (National Mastitis count (SCC) was shown to tie significantly regarding the Council., 1990). detection subclinical mastitis in camels (Abdulrahman, California Mastitis Test (CMT) 1996), together with a good correlation of CMT to milk leukocyte count (Obeid, 1983). Applying CMT and SCC Milk samples were subjected to onsite CMT test. CMT to screen for subclinical mastitis in a group of camels was carried out using the methods as described by led to revealing the predominance of Gram-positive Schalm and Noolander (1957). The CMT solution was bacteria including streptococci spp. and staphylococci obtained from ImmuCell (Portland, USA). Equal vol- spp (Saleh, 2011). Moreover, a similar study in camels ume of milk and CMT working solution were mixed in revealed the predominance of Enterobacterium spp., corresponding testing paddles. The mixture was gently Staphylococcus spp. and Streptococcus spp. in cases of rotated in horizontal position and results were record- subclinical mastitis (Al-Sailihi, 2017). Diverse bacterial ed as negative, weak positive (+), distinct positive (++) species were reported to be implicated in subclinical and and strong positive (+++). Milk samples positive for on- clinical mastitis in camel. This is apparently related to a site CMT test were transported to the laboratory in an location as well as hygiene conditions and their manage- ice box and processed for bacteriological examination ment. A study of subclinical mastitis in camels in a dis- within two hours of collection. Animals with history of trict in Iraq showed that the main isolates involved were mastitis or recent treatment with antimicrobials were coagulase negative Staphylococci followed by Strepto- excluded from this study. coccus spp. and E. coli and Micrococcus spp. were in a Bacteriological Examination lesser extent (Al-Rammahi et al., 2018). In another location, Ali et al. (2019) investigated subclinical mastitis in Bacteriological examination of the samples was carried the two districts in Pakistan and observed the high prev- out following the standard methods as described by alence of S. aureus. In a habitat with close resemblance Quinn et al. (1999). For microbiological analysis, each to Oman, such as that of UAE, isolates from subclinical milk sample (0.1 mL) was streaked on blood agar (Ox- as well as clinical mastitis of camel were identified to be oid, Basingstoke, England) and MacConkey’s agar (Ox- mainly Staphylococcus spp. trailed by Streptococcus spp. oid, Basingstoke, England) and subjected to incubation o and Enterobacterium spp. (Al-Jaboori et al., 2013). at 37 C for 24-48 hours in both aerobic and anaerobic conditions. In the case of no growth, corresponding milk sample was cultured again to obtain growth. The plates with growth were examined for growth colony morphol- ogy, hemolysis, and pigment production.

22 SQU Journal of Agricultural and Marine Sciences, 2021, Volume 26, Issue 1 Asi, Al-Marzooqi, ElTahir, Al Ghaly, Al Toobi, Al Raisi, Haytham Ali, I. Elshafie, H. Johnson

Identification of Bacterial Isolates Discussion All isolates were subjected to Gram staining, catalase, The present study shows the presence of subclinical mas- and oxidase tests. Micrococci spp. and Staphylococci spp. titis in camels in Oman based on CMT and bacterial cul- were identified using Mannitol Salt Agar (Oxoid), and co- ture of milk samples. They also reflect a high correlation agulase test using both slide and tube methods along with between CMT and cultural isolates. Enterobacteriaceae catalase and oxidase testing. All biochemical tests were E. cloacae and E. coli were found as the predominant done according to standard procedures (NCCLS, 2000). bacteria with few coagulase negative Staphylococci and Analytical Profile Index Test Micrococcus sp. E. cloacae isolated in this study belongs to the microbiota in the surrounding environment. This Gram-negative isolates with oxidase negative and cat- is a common commensal in animal digestive tract and is ® alase positive reactions were subjected to API 20E a common member of the human microbiome (Keller et (Biomérieux, France) and were further confirmed us- al., 1998). Our results are in slight discrepancy with oth- ing Vitek2 Gram-negative (GN) test cards (Biomérieux, er reports since we report Enterobacteriaceae E. cloacae ® France) in an automated Vitek 2 instrument. All iso- and E. coli as dominant causative agents in subclinical TM lates were kept in Viabank tubes at -70°C for further mastitis in camels. Reports on isolates from camel cas- use. Gram-positive cocci isolates with positive catalase es from neighboring countries implicate Staphylococcus ® reactions were subjected to API Staph (Biomérieux, and Streptococcus spp. as dominant ones in clinical and France). Staphylococci isolates were subjected to Coagu- subclinical mastitis (Al-Jaboori et al., 2013; Al-Ramma- lase test using the tube coagulase method (Quin, 1998). hi, 2018), in agreement with other reports (Hadel et al., Antimicrobial Sensitivity Test 2018). Though Al-Jaboori et al. (2013) identifiedEntero - bacterium spp. from subclinical mastitis in camels in Antimicrobial susceptibility and minimum inhibitory the UAE, yet the dominant ones were Staphylococcus concentrations (MICs) were determined using automat- and Streptococcus spp. Considering rural management ® ed Vitek 2 instrument with AST cards (Biomérieux, practice, it is likely that cross-infection was established France). Breakpoints used as recommended by the Na- in camels since management and the level of hygiene is tional Committee for Clinical Laboratory Standards not optimal. (NCCLS, 2000). To best of our knowledge this is the initial investigation to report subclinical mastitis in camels in Oman, Results and that the coliform is the dominant type. Not a single camel owner interviewed during sampling was aware of California Mastitis Test and Bacteriological Ex- the concept of subclinical mastitis in camels or use of amination Analysis California Mastitis Test (CMT) screening. Camel milk is A total of 61 camels were examined for subclinical mas- obtained via hand milking without any pre or post milk- titis. Out of 61 animals, 18 (29%) camel milk samples ing dipping. It was even observed camel owners drink- were found to be positive for subclinical mastitis using ing milk right from camel teats using hands, although it California Mastitis Test (CMT), whereas only 15 isolates is not recommended for safety. yielded growth during microbiological analysis. Three E. cloacae is a biofilm forming organism and this samples positive for CMT, did not yield any growth even secretes a number of cytotoxins deemed important for after second culture. Out of 15 positive growths, 7 (47%) its pathogenicity (Mezzatesta et al., 2012). More impor- isolates were confirmed as E. cloacae, 4 (27%) E. coli tantly, due to expression of extended spectrum β-lact- whereas 3 (20%) coagulase negative staphylococci and 1 amases (ESBL) and carbapenemases, it has turned into (7%) isolate was confirmed asMicrococcus spp. third broad spectrum Enterobacteriaceae specie causing nosocomial infections along with K. pneumoniae and E. Antimicrobial Sensitivity Test Analysis coli (Potron et al., 2013). Antimicrobial sensitivity analysis revealed that all E. In last few decades, E. cloacae have been added to the cloacae (100%) isolates were resistant to penicillin, first list of most worrying microorganisms due to their ability generation cephalosporins, and macrolide group of an- to acquire resistance. In humans, E. cloacae are known tibiotics, whereas 3 isolates (43%) shown intermediate to cause septic arthritis, endocarditis, and skin, urinary, resistance to phenicols. All four E. coli (100%) isolates respiratory and abdominal infections. It is contracted via exhibited resistance to penicillin, ampicillin, and amox- skin and gastrointestinal tract (Sanders et al., 1997, Lee icillin, 2 (50%) isolates were resistant to erythromycin et al., 2002). Coliform mastitis is also the most common and tylosin, 3(75%) were resistant to first generation form of clinical mastitis in cattle in different parts of the cephalosporins whereas only 1 (25%) isolate was found world. Among coliforms, E. coli is most commonly iso- resistant to tetracycline. lated from animals with mastitis and primary source of these bacteria are cow feces, environment and infections via teat canal (Sumathi et al., 2008, Lipman et al., 1995).

Research Paper 23 Subclinical Mastitis in Camels in Oman: A Pilot Study

In the present study, Enterobacteriaceae was observed described elsewhere (Leclercq, 2002; Ojo et al., 2004) to be the predominant isolates from camels with subclin- Identification ofEnterobacter cloacae establish- ical mastitis. This is in line with other studies conducted es the fact that the organism is AmpC producer that in cows with mastitis (Bengtsson et al., 2009, Saidi et al., yields the inducible chromosomal AmpC β-lactamase 2014). However, a study done in subclinical mastitis in and therefore it is not necessary to detect AmpC pro- camels in Saudi Arabia, Streptococcus spp., Staphylococ- duction in these isolates (Gupta et al., 2014). Coagu- cus aureus and other staphylococci spp. were found to lase negative Staphylococci (CNS) are opportunistic be the predominant organism (77%) whereas only 12.9% pathogens that may cause infection due to improper isolates were identified as E. coli. (Saleh & Faye, 2011). teat disinfection. CNS are commonly isolated from bo- In another study conducted on subclinical mastitis in vine milk samples as these organisms are part of nor- camels, the authors found coagulase negative staphylo- mal skin flora and contamination of milk is common. cocci (CNS) to be the predominant isolates (35%) and However, infections are usually subclinical in nature. only (10.72%) were confirmed as E. coli (Leyla et al., Raw milk contamination with Enterobacteriaceae can 2017). A study (Al-Rahmmahi et al., 2018) carried on in occur during milking process, contamination of milk with Al-Najaf on 82 camels, the researchers found Coagulase animal feces or mastitis (Dahmen et al., 2013). As camel Negative Staphylococci to be the predominant (17.68%) milk is obtained exclusively by hand-milking, washing followed by Streptococcus spp. (12.92%). The authors hands and udder of the animal, post milking teat dipping, also reported Staphylococcus aureus (10.2%), E. coli pasteurization of milk and prevention of contamination (8.16%) and Micrococcus (4.08%). In our study we found during transport of camel milk can help in control of 3 isolates (20%) of CNS and 1 isolate of Micrococcus. these organisms. The best way forward is the education In the present study, all E. cloacae (100%) isolates of camel owners about dangers of drinking raw camel were found to be resistant to penicillin, first generation milk that can lead to infection with variety of bacteria cephalosporins, macrolides and 43% were intermediate- and importance of pasteurization to avoid infections. ly resistant to phenicols. Currently, there is a lack of con- Consumption of raw camel milk is commonly prac- sensus regarding exact definition of multidrug resistant ticed in Middle East including Oman; therefore, it is organisms in veterinary medicine. In human medicine, important to evaluate the microbiological quality of the for an organism to be reckon as multidrug resistant, it camel milk. More number of camels could not be includ- should be resistant to at least one agent in at least three ed in the study due to various factors including overall antimicrobial classes. However, according to criteria for low camel population in the study area as compared to assessment of multidrug resistance in bacteria (food.gov. other parts of Oman, noncompliance of camel owners to uk), these organisms cannot be considered multi-drug provide milk samples, small holdings (one or two camels resistant as E. cloacae harbors intrinsic resistance to pen- commonly kept along with other livestock animals), and icillin, first generation cephalosporins and cephamycins. non-availability of camels for sampling at holdings due In our study, all E. coli (100%) isolates were resis- to long overall grazing time period. It is concluded that tant to ampicillin, amoxicillin, 3 (75%) were resistant camel owner education programs are required to im- to the first generation cephalosporins, 2 (50%) resis- prove the udder health of the camels, regular screening tant to macrolides whereas 1 (25%) were found re- of camels for subclinical mastitis using CMT, and edu- sistant to tetracyclines. Similar trends have been re- cate them regarding hazards of using raw camel milk. ported in cows with mastitis (Saidi et al., 2014) and camels with subclinical mastitis (Saleh and Faye, 2011). Conclusion and Recommendation Camel milk if consumed raw can be a source of infection for humans. A case of E. cloacae sepsis has This is the initial investigation to report subclinical mas- been reported in a preterm infant feeding on mother’s titis in camels in Oman, and that the coliform is the dom- milk. Same pathogen was cultured from milk samples inant type. In the present study, Enterobacteriaceae was obtained from mother over the period of 7 days. How- observed to be the predominant isolates from camels ever, mother’s milk could not be established as a direct with subclinical mastitis. This is the initial report of iso- cause of E. cloacae infection in infant as other sources lation of E. cloacae and E. coli from camel milk samples of infection could not be ruled out (Weem et al., 2015). positive for subclinical mastitis in Oman. In the pres- Further studies warranted to establish the link between ent study, all E. cloacae (100%) isolates were found to be consumption of raw camel milk and human infections. resistant to penicillin, first generation cephalosporins, All of the isolates (100%) were found to be resistant macrolides and 43% were also intermediately resistant to macrolide antibiotics including erythromycin and ty- to phenicols. In this study, we could conclude that camel losin. Macrolides have shown good activity especially against gram-positive cocci organisms. However, these owner education programs are required to improve the antibiotics have limited efficacy againstEnterobacte - udder health of the camels, regular screening of camels riaceae in general. Enterobacteriaceae may acquire re- for subclinical mastitis using CMT, and educate them sistance against macrolide in a variety of mechanisms regarding hazards of using raw camel milk.

24 SQU Journal of Agricultural and Marine Sciences, 2021, Volume 26, Issue 1 Asi, Al-Marzooqi, ElTahir, Al Ghaly, Al Toobi, Al Raisi, Haytham Ali, I. Elshafie, H. Johnson

Table 1. Percentage resistance of 11 Enterobacteriaceae species from camel positive for subclinical mastitis.

En- Number of resistant isolates (percentage resistance) tero- To- bacte- PEN. riace tal AMP AMC. TIM STR. ENR. ERY. TYL. TET. FFC. C FP. FUR. IPM. GEN. NEO. FLU. ENR. MAR. SXT. LEX. strains CET

E. 7 7(100) 7(100) 7(100) 0(0) 0(0) 0(0) 7(100) 7(100) 0(0) 3(43) 0(0) 0(0) 0(0) 0(0) 0(0) 0(0) 0(0) 0(0) 7(100) 7(100) cloacae

E. coli 4 4(100) 4(100) 4(100) 0(0) 0(0) 0(0) 2(50) 2(50) 1(25) 0(0) 0(0) 0(0) 0(0) 0(0) 0(0) 0(0) 0(0) 0(0) 3(75) 3(75)

Total 11 11(100) 11(100) 11(100) 0(0) 0(0) 0(0) 9(82) 9(82) 1(9) 3(27) 0(0) 0(0) 0(0) 0(0) 0(0) 0(0) 0(0) 0(0) 10(90) 10(90)

PEN: Penicillin; AMP: Ampicillin; AMC: Amoxicillin + Clavulanic acid; TIM: Ticarcillin/Clavulanic acid; STR: Streptomycin; ENR: Enrofloxacin; ERY: Erythromycin; TYL: Tylosin; TET: Tetracycline; FFC: Florfenicol; CFP: Cefoparazone; FUR: Ceftiofur ; IMP: Imipenem ; GEN: Gentamicin; NEO: Neomycin; FLU: Flumequine ; ENR: Enrofloxacin ; MAR: Marbofloxacin ; SXT: Trimethoprim/Sulfamethoxazole; LEX: Cefalexin; CET: Cefalotin;

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Research Paper 25 Subclinical Mastitis in Camels in Oman: A Pilot Study

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26 SQU Journal of Agricultural and Marine Sciences, 2021, Volume 26, Issue 1 Journal of Agricultural and Marine Sciences 2021, 26(1): 27–36 DOI: 10.24200/jams.vol26iss1pp27-36 Reveived 11 May 2020 Accepted 13 Aug 2020 Research Paper Biological Efficiency and Control of a Membrane Bioreactor and Conventional Activated Sludge Process for Treating Municipal Wastewater

Buthaina Mahfoud Al-Wahaibi1, 2, Abdullah Al-Mamun1, *, Mahad Said Baawain1, Ahmad Sana

الكفائة و التحكم البيولوجي يف مفاعل حيوي غشائي و عملية احلمأة املنشطة التقليدية ملعاجلة مياه الصرف الصحي البلدية بثينة الوهييب1 ، 2، عبدهللا املأمون1 ، * ، حماد سعيد ابعوين1، أمحد سنا Abstract. The performance of a membrane bioreactor (MBR) was compared to a conventional activated sludge (CAS) process and it was aimed to identify the best technological option for a municipal sewage treatment plant (STP). The MBR system was fed by the diluted sewage coming from the main municipal sewer network, which contained an averagely lower concentration of organics, inorganics and biological pollutants. While the CAS system was fed by a concentrated sewage coming from household septic tanks, contained averagely high concentration of organics, inorganics and biological pollutants. CAS showed a higher removal efficiency of biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), volatile suspended solids (VSS), Fat-Oil-Grease (FOG), nitrogen, phosphorous, helminths ova (HO), and pathogenic bacteria compared to the MBR. Nevertheless, the removal efficiencies of nitrogen, HO and pathogenic bacteria in the case of CAS were lower than MBR due to the high concentration of those parameters in the influent fed to CAS. However, both the efficiency and the amount of removal for phosphorous in the case of CAS was quite higher than that of MBR due to extended aeration in CAS. The pathogenic bacteria and HO were removed almost 99.97% by the MBR, whereas the CAS removed 91±5% of the pathogenic bacteria and HO. Therefore, the effluent of the CAS system required additional disinfection for the reduction of pathogens and HO. In terms of biological efficiency and influent flexibility, both the systems can satisfy the national standards. Overall, the data suggested that CAS possessed a higher capacity of treating concentrated sewage for removing all pollutants to satisfactory limits except complete removal of pathogenic bacteria and HO. It was obvious that MBR possessed a membrane barrier to retain the pathogens and HO; therefore, they could be removed up to very low levels. However, further investigation is necessary to verify the MBR performance using the same concentrated sewage as CAS. Keywords: Membrane bioreactor; Conventional activated sludge; Municipal wastewater treatment; Removal efficiency; Sewage treatment plant; National standards. املســتخلص:متت مقارنــة أداء مفاعــل غشــائي حيــوي )MBR( بعمليــة احلمــأة املنشــطة التقليديــة )CAS( وذلــك لتحديــد اخلياراألفضــل التكنولوجــي حملطــة معاجلــة ميــاه حمطــة صــرف الصحــي بلديــة. متــت تغذيــة املفاعــل احليــوي الغشــائي مــن ميــاه الصــرف الصحــي املخفــف القادمــة مــن شــبكة الصــرف الصحــي ابملناطــق احلضريــة الرئيســية، الــي حتتــوي علــى معــدل تركيــز أقــل مــن املــواد العضويــة، غــر العضويــة وامللــواثت البيولوجيــة. يف حــن متــت تغذيــة نظــام املنشــطة التقليديــة مــن ميــاه الصــرف الصحــي املركــزةالقادمــة مــن خــزاانت الصــرف الصحــي املنزليــة،و الــي حتتــوي علــى متوســط تركيــز ٍعــال مــن املــواد العضويــة وغــر العضويــة وامللــواثت البيولوجيــة. أظهــرت نظــام احلمــأة املنشــطة التقليديــة علــى كفــاءة إزالــة أعلــى مــن الطلــب البيوكيميائــي األكســجي ) (BOD ، الطلــب علــى االكســجي الكيميائــي ) ( ،COD إمجــايل املــواد الصلبــة العالقــة ) ( TSS، املــواد الصلبــة املعلقــة ،) (VSS ، املركبــات الدهنيــة )FOG( ، النيرتوجــن ، الفوســفور، بويضــات الديــدان) (،و HOالبكتــراي املســببة لألمــراض، مقارنــة ابملفاعــل الغشــائي احليــوي. ومــع أن كفــاءة إزالــة النيرتوجــن ، بويضــات الديــدان، والبكتــراي املســببة لألمــراض يف حالــة نظــام احلمــأة املنشــطة التقليديــة كان أقــل مــن املفاعــل الغشــائي احليــوي بســبب الرتكيــز العــايل مــن هــذه العوامــل يف النظــام املغــذي للحمــأة املنشــطة التقليديــة. ومــع ذلــك، فــإن كال مــن كفــاءة وكميــة إزالــة الفوســفور يف نظــام احلمــأة املنشــطة التقليديــة كان أعلــى جــدا مــن ذلــك يف املفاعــل الغشــائي احليــوي بســبب التهويــة املمتــدة يف نظــام احلمــأةاملنشــطة التقليديــة. متــت إزالــة البكتــراي املســببة لألمــراض و بويضــات الديــدان بنســبة 99.97٪ تقريبــا ًبواســطة املفاعــل الغشــائي احليــوي ، يف حــنأزالــت نظــام احلمــأة املنشــطة التقليديــة 91 ± ٪ 5مــن البكتــراي املســببة لألمــراض و بويضــات الديــدان. لذلــك ، يتطلــب تدفــق نظــام احلمــأة املنشــطة التقليديــة ًتطهــرا إضافيًــا لتقليــل مســببات األمــراض و بويضــات الديــدان. مــن حيــث الكفــاءة البيولوجيــة ومؤثــر املرونــة ، فــإن كال النظامــن ميكــن أن يلــيب املعايــر الوطنيــة. وعمومــا، تشــر البيــاانت إىلأن نظــام احلمــأة املنشــطة التقليديــة ميتلــك قــدرة أعلــى علــى معاجلــة ميــاه الصــرف الصحــي املركــزة إلزالــة مجيــع امللــواثت إىل حــدود مرضيــة ابســتثناء إزالــة كاملــة للبكتــراي املســببة لألمــراض وبويضــات الديــدان. كان مــن الواضــح أن املفاعــل الغشــائي احليــوي وضــع ًحاجــزا غشــائيا ًلالحتفــاظ مبســببات األمــراض و بويضــات الديــدان ؛ وابلتــايل، فإنــه ميكــن إزالتهــا إىل أدىن املســتوايت. ومــع ذلــك، فانــه مــن الضــروري إجــراء املزيــد مــن البحــث للتحقــق مــن أداء املفاعــل الغشــائي احليــوي ابســتخدام نفــس ميــاه الصــرف الصحــي املركــزة مثــل نظــام احلمــأة املنشــطة التقليديــة. الكلمات املفتاحية: املفاعل احليوي، نظام احلمأة املنشطة التقليدية، الصرف الصحي، كفائة االزالة، نظام الصرف الصحي، املعايي الوطنية Biological Efficiency and Control of a Membrane Bioreactor and Conventional Activated Sludge Process for Treating Municipal Wastewater

Introduction gen, and recovery of electrical energy (Ryue et al., 2020; Lefebvre et al., 2008a; 2008b; 2009; 2010; Al-Mamun and he growing scarcity of water resources in arid re- Baawain, 2015). However, this up-gradation can be fea- gions, like the Sultanate of Oman, has extensive- sible only by exploring the cost-effective materials and ly increased the necessity to preserve the current appropriate reactor designs with combined MBR-MFC Tresources for drinking purposes (Oliver et al., 2008; Za- system (Al-Mamun et al., 2016; 2017a; 2017b; Chung et netti et al., 2010). To do so, municipal wastewater plants al., 2020). have been established to treat wastewaters and support Recent studies have revealed some insight on com- the sustainable development of the country (Baawain et paring CAS to MBR process in a variety of industrial al., 2020; 2019a; 2019b; Iglesias et al., 2010; Papa et al., wastewater systems, such as a winery (Valderrama et 2016). al., 2012), tannery (Munz et al., 2008), textile factory Wastewater is often treated by a conventional acti- (Malpei et al., 2003), or municipal sewage (De Luca et vated sludge (CAS) process, which includes the steps of al., 2013; Liu et al., 2009; Zanetti et al., 2010). However, biological, physical and chemical treatment. The physi- the biological efficiency of MBR and CAS processes in cal treatment during the CAS process, such as conven- the municipal wastewater industries has not been car- tional solids settling and sand filtration, cannot remove ried out extensively. The review of previous studies re- all the contaminants up to the desired level. Therefore, vealed that selected polar pollutants in municipal waste- subsequent chemical or physical treatment steps, such water, the MBR removal efficiency in laboratory studies as chlorination and/or UV ray treatment are required. was significantly greater than that of the CAS, while no The implementation of such chemical treatments al- improvement has been recorded for other pollutants ready has identified as risks and threats to the environ- (Weiss and Reemtsma, 2008). The pilot MBR resulted in ment and public health as it discharges chemicals and higher removal of chemical oxygen demand (COD) (i.e. chemicals by-products as effluent into aquatic systems 93%), suspended solids (>99%) and microorganisms as (Chitrakar et al., 2019; Al-Mamun, 2017; Baawain et al., well as a color abatement. While, the chemical remov- 2017; Zanetti et al., 2010). In order to improve the efflu- al efficiency was very variable and it was particularly ent quality before final disposal, membrane-based tech- amongst the different classes of organic contaminants nology can be better alternatives for removing tiny solid (Gerbersdorf et al., 2015). In other words, the MBR sys- particles and pathogenic microbes without any usages of tem has demonstrated consistent performance in treat- eco-threatening chemical treatment steps (chlorination ing high-strength and fluctuating strength wastewater in or ozonation) (Jafary et al., 2018; 2020a, 2020b, Al Lawa- pilot scales (Chang et al., 2008). ti et al., 2019). In recent decades, advanced wastewater treatment In sewage treatment plants (STPs), a microporous technologies, such as MBR, are of particular attention, membrane for filtration purposes combined with a bi- because of the thorough removal efficiency of the sus- ological wastewater treatment known as a membrane pended and dissolved chemical and biological compo- bioreactor (MBR) is utilized (Collivignarelli et al., 2017; nents from wastewater (Petrović et al., 2003; Barua et al., Melin et al., 2006). Over the last decades, MBR has prov- 2018; 2019). However, the experimental efforts to com- en to be a valuable alternative for CAS plants (Van den pare the removal efficiency of different components in Broeck et al., 2010). Because, MBR has some major ad- real plants have been lacking. This is due to the fact that vantages than that of the CAS, including small footprint, it is not feasible to acquire statistical rigorous data from superior quality effluents (no chemicals and chemical a full-scale treatment plant. Thus, the available compar- by-products), and sludge reduction (Drews, 2010; Jeison ative studies have normally been limited to only a few and Van Lier, 2007; Judd, 2010; Tewari et al., 2010). For pilot-scale cases, which make it extremely problematic example, the MBR processed water from an integrated to generalize the results on a global scale with any sort of process in Germany provided a water quality that fully assurance. Therefore, in order to gain an understanding meets the requirements of a washing process (Hoinkis of the removal efficiencies of organics, inorganics and and Panten, 2008). However, the MBR has the drawback biological pollutants from a full-scale treatment plant, a of membrane fouling, leading to an increased energy de- case study of municipal wastewater treatment compar- mand due to increased trans-membrane pressure and ing the MBR and CAS technologies was carried out. The influenced the removal efficiencies and nitrous oxide samples were collected from three different locations, emission (Van den Broeck et al., 2012; Mannina et al., which were influent raw sewage (RS), biological aeration 2017). For this reason, an upgraded version of MBR with tank and treated effluent. The emphases of this study microbial fuel cell (MFC) for sewage treatment is quite were to characterize the strength of influent RS, distin- essential for combined removal of organics and nitro- guish the concentration load in the biological treatment Abdullah Al-Mamun1,*( ) [email protected], 1Department of tank, calculate the removal performance of each param- Civil and Architectural Engineering, Sultan Qaboos University, PO Box eter, and compare the quality of treated effluents to the 2 33, PC 123, Muscat, Sultanate of Oman. Al-Ansab Sewage Treatment ministry of environment and climate affairs (MECA) Plant, Haya water, PO BOX 1047, PC 133, Muscat, Sultanate of Oman. standards in Muscat, Sultanate of Oman. Furthermore,

28 SQU Journal of Agricultural and Marine Sciences, 2021, Volume 26, Issue 1 Al-Wahaibi, Al-Mamun, Baawain, Sana

Table 1. Wastewater Characteristics at Al-Ansab STP membrane was made of chlorinated polyethylene with Parameter Units Minimum Maximum maximum (nominal) pore size of 0.4 μm (average: 0.2 μm) which blocks most microorganisms in the activated sludge. The submerged membrane panel was aerated by Biochemical Oxygen De- mg L-1 350 400 a coarse bubble system underneath each unit, which was mand (BOD5) necessary to prevent rapid membrane fouling and mi- Chemical Oxygen Demand mg L-1 600 900 crobial degradation of the pollutants. The flat plate con- (COD) figuration kept enough space between the membranes Total Suspended Solids mg L-1 350 500 (TSS) so that the debris accumulation was minimum. In-situ Volatile Suspended Solids chemical cleaning was the only maintenance typically mg L-1 280 400 (VSS) required for such system. The chemical cleaning was VSS/TSS Ratio % 75 85 done using the standard protocol supplied by the manufacturer (Sánchez, 3013). Total Kjeldahl Nitrogen mg L-1 50 70 (TKN) Sampling Procedure Ammonia Nitrogen mg L-1 35 45 (NH3-N) The sampling procedure consisted of sampling loca- Total Phosphorous (TP) mg L-1 9 15 tions, sample types, sample equipment and sample col- -1 lection. Influent RS, biological aeration tank and treated Total Alkalinity (as CaCO3) mg L 100 200 effluent locations were selected as the sampling points. Oil and Grease mg L-1 NA 200 To ensure good mixing and minimization of settled solid samples were collected near the center of the flow pH [-] 6.0 8.0 channel at approximately 40 to 60% of the water depth, Temperature °C 20 35 where the turbulence was at a maximum level. However, the most desirable locations were not accessible all the the performance of the current CAS and MBR systems time. Sample collection was carried out from January to were compared with respect to the measured parame- March 2014 and the reported values demonstrated the ters. This study allows a technological recommendation average values of different experiments (n = 24) with for the optimization of the STPs in the municipal waste- their standard deviations. water treatments. Design Characteristics Materials and Methods Plant Design Condition for RS: Wastewater arrives at the Al-Ansab STP from the sewage pumping stations Process Description of Old Al-Ansab STP and by tanker trucks, which are mainly from domestic sources (residential, commercial, and institutional). The Old Al-Ansab STP, located in south Muscat (Figure 1), combined influent wastewater was analyzed in accor- was commissioned in 1990 and then handed to Haya dance with the standard methods for the examination of Water in 2006. The old STP was designed to treat annual water and wastewater. Table 1 shows the characteristics 3 -1 average flow of 12,000 m day with a peak flow of up to of the RS. Detailed discussion in this regard has been 3 -1 24,000 m day . The old STP consists of five main units, provided elsewhere (Baawain et al., 2014). including tanker discharge area, pre-treatment facilities, secondary biological treatment, filtration, and chlori- Analytical Methods nation. The plant was designed to treat the wastewater A set of analytical methods was implemented to under- by the CAS process at solids retention time (SRT) of 21 stand the performance of the CAS and the MBR process. days. Total suspended solids (TSS) and volatile suspended Process Description of the New Al-Ansab STP solids (VSS) were determined by applying the standard method (method 2540) and the gravimetric method was The new Al-Ansab STP is an integral part of the Mus- carried out using a glass-fiber filter. The measurement cat wastewater scheme project (MBR based technol- and analysis of nitrogen are important because it is the 3 -1 ogy) with a plant average capacity of 55,000 m day . building block in the synthesis of organic matters. To- The new plant was commissioned in 2010 to serve the tal nitrogen (TN) was calculated from the major form Bausher Catchment. The treatment process consisted of of nitrogen as comprised of organic nitrogen, ammonia, six main units, which were preliminary treatment, bio- nitrite and nitrate. The following equation shows the logical treatment and solids separation, treated effluent determination of TN from its elements (Sawyer et al., storage, sludge dewatering, chemical storage/dosing and 1994). odor control system. The MBR process included flat sheet membrane panels (Kubota Submerged Membrane TN = Organic N + NH3-N + NO2-N + NO3-N (Eq. 1) UnitTM, SPC400, Japan) housed in units. The flat sheet

Research Paper 29 Biological Efficiency and Control of a Membrane Bioreactor and Conventional Activated Sludge Process for Treating Municipal Wastewater

Figure 1. Areal map of Al-Ansab STP showing the location of the treatment units and facilities.

The organic nitrogen and total Kjeldahl Nitrogen (TKN) RS Characteristics were determined analytically according to the standard In order to quantify the performance in CAS and MBR method for examination of water and wastewater (meth- systems, the characteristics of RS has in terms of phys- od 4500-N) (Eaton, 1995). TKN is the total amount of icochemical and biological parameters of wastewater. organic and ammonia Nitrogen. Depending on the pH Figure 2 showed the average concentration of RS param- of wastewater, ammonia nitrogen exists in aqueous solu- eters during the study period. The RS influent showed tion as either the ammonium ion (NH +) (dominant at 4 the physicochemical parameters with low or even trace pH<7) or ammonia gas (NH ). Nitrate and nitrite were 3 concentration of FOG, nitrogen, phosphorus, and HO measured by using ion chromatography method. Total compared to the other biological parameters. As shown phosphorus was determined in the wastewater matrix in Figure 2, the differences between the other sewage pa- using HACH/LANGE test cuvettes. The intensity of the rameters (BOD, COD, TSS, and VSS) were significant. blue color was measured using a spectrophotometer. This was due to the fact that the MBR was fed by a large The procedure is suitable for the concentration of 0.05 quantity of diluted municipal wastewater through do- to 20 mg L-1 of PO 3--P. 4 mestic sewer network; while, the CAS system was fed The respirometric method covers the determination with concentrated wastewater from household septic of biochemical oxygen demand (BOD) of water and tanks, commercial and light industries through tankers. wastewater within a 5-day incubation period (BOD ). 5 The average values of BOD and COD are present- The test analysis was based on the standard methods for 5 ed in Figure 2. According to Metcalf and Eddy (2004), the examination of water and wastewater (method 5210) the average values of BOD in RS were categorized as (Eaton, 1995). Besides, the COD was determined by the 5 high strength for CAS (491.81 mg L-1); whereas, it was spectrophotometric method (method 5220). The oil and classified as a medium-strength concentration (229.44 grease were identified by infrared spectroscopy accord- mg L-1) for MBR. Simultaneously, the average values ing to the standard method 5520. Determination of fecal of COD for the CAS and MBR were 808.42 mg L-1 and coliform (FC) in water and wastewater was carried out 607.82 mg L-1, respectively. This might be related to the by using multiple tube fermentation (method 9221) as introduction of some industrial organic pollutants that explained by Eaton (1995). Helminths ova (HO) were were received by tankers at CAS. The higher concentra- measured by the standard provided here (ASTM, 2004). tions of degradable COD required a large-volume aeration basin, more oxygen transfer facilities and greater Results and Discussion sludge production. The performance analysis of CAS and MBR systems was In order to save cost and time, it was also useful to achieved by investigating different biochemical param- know the relation between BOD5 and COD in each eters in influents and effluents of the two systems. The sampling location. The RS BOD5/COD ratios for CAS results were compared with the MECA standards (A and MBR were measured as 0.61 and 0.38, respective- and B), which indicated the national requirements of the ly. These ratios were within the typical range of 0.30 final effluent for irrigation applications or sea-disposal. to 0.80 for RS as reported by Metcalf and Eddy (2004). Moreover, the values indicated that the RS was mainly composed of domestic wastewater without any toxic elements. The absence of toxic elements in RS was favour-

30 SQU Journal of Agricultural and Marine Sciences, 2021, Volume 26, Issue 1 Al-Wahaibi, Al-Mamun, Baawain, Sana

Figure 2. Raw sewage characteristics of the CAS and MBR processes. able to decompose the organic matters easily. Besides, concentration in the MBR influent was reasonably low. in the CAS system, BOD concentration in the aeration Removal Performance tank rose slightly by 260 mg L-1 compared to those of the MBR. Such increment of BOD in the aeration tank Similar to influent, the physicochemical and biological of CAS system was within the limiting value of STP’s de- parameters of the treated effluent from two systems, sign criteria, where the moderately concentrate microbi- CAS and MBR, were measured and analyzed. The anal community (mix liquor suspended solid, MLSS) could alytical results of the treated effluent parameters are oxidize the organics load in a longer retention time. shown in Figure 3. In order to check the suitability of the Solids in STPs were analyzed by using gravimetric treated wastewater for irrigation purposes or discharge method. As shown in Figure 2, the average TSS was to the sea, the compliance of treated water was identi- about 442.21 mg L-1 and 137.76 mg L-1 for CAS and fied by comparing it with the MECA standards. Figure MBR, respectively. Based on Metcalf and Eddy (2004), 3 illustrates that the BOD5 quality of the treated efflu- RS influent of the CAS and MBR plant could be classi- ent for CAS and MBR were within the acceptable range fied as high strength and medium strength, respectively. defined by MECA standards (7.38 mg L-1 and 3.28 mg Such an amount of TSS could be attributed to the high L-1, respectively). For COD, the treated effluents were load of solids received by the tankers. The average VSS in compliance with the MECA standards with the values concentrations in the RS were 214.61 and 55.06 mg L-1 of 36.78 mg L-1 and 15.14 mg L-1, respectively; where the for CAS and MBR plant, respectively. From the obtained MECA standards were defined as 150 mg -1L and 200 values of TSS and VSS, the VSS/TSS ratios in influent mg L-1 for the upper and lower limits. In addition, no were 0.49 and 0.40 for CAS and MBR plants, respective- standard had been reported for VSS by MECA. ly. The rests were fixed inorganic suspended solids that The TSS and VSS values for the CAS process were ob- remained even after ignition at 550 °C. tained after a sand filter and before chlorination, while in TN and TP data could be used to evaluate the treat- the MBR process, the samples were taken after filtration. ability of wastewater by biological processes. The re- In practice, the high percentage of TSS from the CAS sults in Figure 2 showed that the major parts of the TN process could be due to improper mechanical screening. compounds were ammoniacal and only small parts were Moreover, negligible primary sedimentation tank had nitrate. It was worth to mention that the ammoniacal ni- been installed in both STPs that allowed the heavy solids trogen (NH3-N) served as substrates of the nitrifying mi- to settle down. The concentration level of FOG was al- crobes. The CAS plant received a denser concentration most negligible from both systems. The effluent concen- of nutrients (N and P) than that of the MBR, which was trations of nitrogen and TP were found in a reasonable classified as a high strength influence according to Met- range, except for TKN and NH3-N. The concentration calf and Eddy (2004). The TP fed to the CAS system was level of TKN at old STP was about 24.11 mg L-1, which approximately double the concentration that fed to the was above the limit of MECA standards (5 and 10 mg -1 MBR. This might be due to the partial mixing of septic L , respectively). The concentration of TKN, NH3-N, tank sewage with the light industrial wastewater in the and NO3-N of the MBR were within the standard limits, case of CAS. The higher concentration of TP was due where the measured values were 0.86, 0.26, and 5.96 mg to the mixing of industrial wastewater as it contained L-1, accordingly. Furthermore, the concentration limits a higher concentration of phosphorus. Overall, the TP of TN for both processes were obtained satisfactorily.

Research Paper 31 Biological Efficiency and Control of a Membrane Bioreactor and Conventional Activated Sludge Process for Treating Municipal Wastewater

Figure 3. Effluent characteristics of the CAS and MBR processes.

The concentration of NH3-N slightly exceeded from the CAS. The MBR was able to remove up to 99% of NH3-N standard value, which was the same as TKN. This could and approximately 83% of the TN, whereas the CAS be due to an insufficient amount of dissolved oxygen was only able to remove approximately 55% of TN. Be- supplied by very old aerators as well as a lack of adequate sides, TKN and NH3-N removal in the case of MBR was air diffusers installed at the bottom of the tank. greater than 98%, while such values for the CAS system Removal Efficiency were 61% and 80%, respectively. The results of the nitrogen and ammonia removal from the MBR system were The physicochemical and biological parameters as dis- similar to the reported studies for municipal wastewa- cussed in influent and effluent, the removal performanc- ter (Côté et al., 1997; Mohammed et al., 2008), where es (in removal percentages) of the similar parameters González et al. (2007) found similar results in a poorly from the two systems are shown in Figure 4. Organics performing CAS system in terms of ammonia removal. in terms of BOD5 and COD were removed by more than The remaining nitrogen (organic nitrogen) had a com- 95% in the MBR as well as the CAS treatment system. plex structure that made it difficult to degrade. The- un Particles in the form of TSS were removed up to 98% acceptable removal efficiency of nitrogen in CAS had a in the MBR and 97% in the CAS system. Regarding the negative impact on the system performance by grow- VSS, the MBR performed slightly better as up to 96.8% ing algae inside the facilities. Hence, the MBR system removal compared to 94.7% in the CAS system. FOGs showed a better performance, which could be due to the were removed by greater than 99% in both the systems. fact that the old aeration equipment in the CAS system Regarding the nitrogen and HO removal, the MBR supplied oxygen to nitrifying microbes and this did not showed a better performance compared to that of the meet the demand to achieve full nitrification. However,

Figure 4. Treatment efficiency of the CAS and MBR processes in percentage (%).

32 SQU Journal of Agricultural and Marine Sciences, 2021, Volume 26, Issue 1 Al-Wahaibi, Al-Mamun, Baawain, Sana

Figure 5. Treatment efficiency of the CAS and MBR processes in amount (mg∙L-1) in the MBR system nitrates were formed probably due to MPN/100 mL as per standard B and A of MECA. Thus, incomplete denitrification, which effectively increased additional disinfection was required for the reduction of the concentration of nitrate. An additional denitrifica- pathogens and HO in the CAS process. tion step would be necessary for complete nitrate re- Removal Amount moval. In the CAS system less nitrogenous compounds, e.g., ammonia and organic nitrogen, were removed and Figure 5 shows the removal amount instead of removal therefore less nitrates were formed because of relatively efficiency. With the current load, CAS showed a high- poor aeration equipment. er amount of removal in the case of BOD, COD, TSS, CAS system still showed a better performance in the VSS and even FOG. In the case of nitrogen, although case of TP removal compared to that of MBR. The TP the removal amounts were similar, the removal efficien- was removed by 88% in CAS, while 54% in MBR. MBR cy (Figure 4) was different. This was because of this fact system showed almost 99.97% removal of HO. This that the influent concentration of nitrogen in the case of higher removal efficiency of HO in MBR was due to CAS was higher than that of MBR. In other words, the the physical separation of particulate matters by mem- CAS system was responsible for treating concentrated brane barriers, while the CAS removed only 91±5% of wastewater from household septic tanks, commercial HO through the sedimentation of other biomasses. Pore and light industries, which was more concentrated than sizes of the MBR system were small enough to separate the diluted municipal wastewater through the domestic solids and microbes from the bulk volume of settling sewer network to the MBR. water by almost 100%. The presence of HO in the efflu- The results in Figure 5 suggested that the CAS sys- ent of CAS could be due to incomplete sedimentation of tem presented superior performance to the MBR in al- it in the sand filter. However, the removal performance most all of the investigated criteria, except for nitrogen of biological pollutants using the MBR technology was removal as in this case the CAS system underperformed more reliable than that of membrane filtration, because due to the unsuitable aeration equipment. In order to it removed particles more reliably than a settling basin achieve full comparability of the two treatment process (De Luca et al., 2013). However, both the values were plants, further investigation is necessary to examine if satisfied by MECA standards. In both cases, the efflu- the MBR performs equally under the same conditions ent concentration of HO was below the limits set by the as of the CAS. national standards, deeming the treated effluent suitable for irrigation applications. Conclusion The removal performance of FCs was exceptional in both systems (>99%). This fact was attributed to the This study investigated the biological and physical re- smaller pore size of membrane sheets that did not al- moval performances of two existing municipal waste- low the bacteria (greater than 0.04 µm) to permeate. water treatment systems as CAS and MBR in Muscat, On the other hand, the discharged FCs of CAS was Sultanate of Oman. Diluted sewage from the municipal very small compared to that of the inlet Coliform in network was being treated in MBR, whereas the con- RS. The resultants bacteria before disinfection by sodi- centrated wastewater from household septic tanks and um hypochlorite and before discharging to the network light industries was being treated in CAS. On average, were decreased to less than 1000 MPN/100 mL and 200 both the systems performed more than 95% removal of BOD, COD, TSS, VSS, and FOG up to the national stan-

Research Paper 33 Biological Efficiency and Control of a Membrane Bioreactor and Conventional Activated Sludge Process for Treating Municipal Wastewater

dards of the country. This leads to the conclusion that sisted marine aerobic biofilm on cathode. Biochemi- both systems showed stable and robust performance cal Engineering Journal 128: 235-242. (removal percentage) with varying influent qualities. Al-Mamun A, Lefebvre O, Baawain MS, Ng HY. (2016). Specifically, the removal of nitrogenous compounds by A sandwiched denitrifying biocathode in a microbi- MBR was quite superior (34% higher) to that by the CAS al fuel cell for electricity generation and waste mini- system. While the amount of phosphorus removal by mization. Int. Journal of Environmental Science and CAS was quite higher than that of MBR due to extend- Technology 13: 1055-1064. ed aeration in CAS. For HO and pathogenic microbes, American Society of Testing and Materials (ASTM). the MBR system was to be preferred due to its almost (2004). AFNOR PR XP X 33-031- Enumeration of complete solid retention by the membrane, which elimi- viable helminth eggs in sludges - Double flotation nated the necessity of subsequent disinfection process as method in a Sodium nitrate solution April 2004, compared to CAS. However, the removal amounts (mg ASTM 07066-04, vol. 11.02. L-1) for all the biological parameters by CAS were quite higher than that by the MBR indicated that the CAS sys- Baawain M, Al-Mamun A, Omidvarborna H, Al-Sulaimi tem possessed the handling capabilities of concentrated IN. (2019a). Measurement, control, and modeling of sewage. Therefore, further investigation is needed to en- H2S emissions from a sewage treatment plant. Inter- sure whether the MBR is flexible enough to achieve sim- national Journal of Environmental Science and Tech- ilar removal capabilities as the CAS has for concentrated nology 16(6): 2721-2732. sewage under similar operating conditions. Baawain M, Al-Mamun A, Omidvarborna H, Al-Jabri A. (2017). Assessment of hydrogen sulfide emission Acknowledgement from a sewage treatment plant using AERMOD. Environmental Monitoring and Assessment 189(6): The authors wish to extend their appreciation to The 1-11 (Article 263). Research Council (TRC) and Sultan Qaboos University Baawain MS, Al-Mamun A, Omidvarborna H, Al-Mu- (SQU), Muscat, Oman, for the financial support through jaini F, Choudri BS (2019b). Residents’ concerns and project no (SR/ENG/CAED/17/01) and (RC/RG/ENG- attitudes towards municipal solid waste manage- CAED/19/01). The authors would like to acknowledge ment: opportunities for improved management. In- the field and logistic support from Haya Water Compa- ternational Journal of Environment and Waste Man- ny. agement 24(1): 93-106. References Baawain MS, Al-Mamun A, Omidvarborna H, Al-Sabti A, Choudri BS. (2020). Public perceptions of reusing Al Lawati MJ, Jafary T, Baawain MS, Al-Mamun A. treated wastewater for urban and industrial applica- (2019). 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36 SQU Journal of Agricultural and Marine Sciences, 2021, Volume 26, Issue 1 Journal of Agricultural and Marine Sciences 2021, 26(1): 37–46 DOI: 10.24200/jams.vol26iss1pp37-46 Reveived 17 Feb 2020 Accepted 22 Aug 2020 Research Paper Mean Sea Level Variability along the Northern Coast of the Oman Sea and its Response to Monsoon and the North Atlantic Oscillation Index from Tide Gauge Measurement

S. Hassanzadeh1,*, F. Hosseinibalam1 متوسط التباين يف مستوى سطح البحر على طول الساحل الشمايل لبحر عمان واستجابته للرايح املومسية ومؤشر تذبذب مشال األطلسي من مقياس املد واجلزر س. امسعیل حسن زاده و ف. حسینی ابالم

Abstract. Sea level analysis along the Northern Coast of the Oman Sea was investigated on the basis of tide gauge measurements. Meteorological parameters, along with monsoon and NAO (North Atlantic Oscillation) indices were used to study the response of sea level to local and global forcing. The relation between sea level and forces were examined. Low correlation coefficient (-0.35) between sea level and atmospheric pressure at Chabahar indicated that the response to atmospheric pressure was not an inverse barometric. The nature of local inverse barometric effects were examined through a series of statistical models. Analysis between sea level and atmospheric pressure reveals a significant coherence, which meant that along the Northern Coast of Oman Sea, mean sea level responded to atmospheric pressure as an inverse barometer. It can be noticed that the difference between atmospheric pressure and mean sea level was due to alongshore wind stress forcing and was consistent with that expected from Ekman dynamics. The four EOF modes capture 87.16% for the x-component and 94.70% for the y-component of the total variance and were statistically significant. Linear regression and ARIMA model forecasts were fitted to sea level and compared to the actual data. Even though both models gave similar results, the ARIMA model performed considerably better. Keywords: The Oman Sea, Tide Gauge, ARIMA, Monsoon املســتخلص: مت حتليــل مســتوى ســطح البحــر علــى طــول الســاحل الشــمايل لبحــر عمــان علــى أســاس قياســات املــد واجلــزر، حيــث اســتخدمت مؤشــرات األرصــاد اجلويــة إىل جانــب مؤشــرات الــرايح املومس ــة يوتذبــذب مشــال األطلســي لدراســة اســتجابة مســتوى ســطح البحــر للتأثــرات احملليــة والعامليــة وفحــص العالقــة بينهــا وبــن مســتوى ســطح البحــر. ووجــد أن معامــل االرتبــاط املنخفــض )- ( 0.35بــن مســتوى ســطح البحــر والضغــط اجلــوي يف تشــاهبار يشــر إىل أن االســتجابة للضغــط اجلــوي مل تكــن أتثــرات جويــة معكوســة، حيــث مت فحــص طبيعــة التأثــرات اجلويــة العكســية احملليــة مــن خــالل سلســلة مــن النمــاذج اإلحصائيــة، وقــد كشــف التحليــل بــن مســتوى ســطح البحــر والضغــط اجلــوي عــن وجــود متاســك كبــر، ممــا يعــي أن متوســط مســتوى ســطح البحــر علــى طــول الســاحل الشــمايل لبحــر عمــان قــد اســتجاب للضغــط اجلــوي بشــكل عكســي، وقــد لوحــظ أن الفــرق بــن الضغــط اجلــوي ومتوســط مســتوى ســطح البحــر حــدث بســبب أتثــر إجهــاد الــرايح علــى طــول الشــاطئ والــذي كان ًمتســقا مــع املتوقــع مــن ديناميكيــات إيكمــان، ووجــد أن أوضــاع EOF األربعــة قــد إلتقطــت مــا مقــداره 87.16٪ للمكــون x و 94.70٪ للمكــون yمــن التبايــن اإلمجــايل والــي كانــت ذات داللــة إحصائيــة، وقــد مت ضبــط االحنــدار اخلطــي وتوقعــات منــوذج ARIMA علــى مســتوى ســطح البحــر ومقارنتهــا ابلبيــاانت الفعليــة، وعلــى الرغــم مــن أن كال النموذجــن أعطيــا نتائــج مماثلــة إال أن أداء منــوذج ARIMA كان األفضــل. الكلمات املفتاحية: الكلمات املفتاحية: حبر عمان، مقياس املد واجلزر، ARIMA، الرايح املومسية Introduction es can be divided into dynamic and quasi-static components (Stammer et al., 2013). For various reasons, the sea he coastal environment is very vulnerable to the level can be changed quite differently from one region changes in the mean sea level, wave heights and to another (Ding et al., 2001). According to Eshghi et al. wave direction. Many forces in the atmosphere (2020), the inverted barometer effect was significant in Tand the ocean influence the sea level. Thus, the sea level the north-western Indian Ocean. Siddig et al. (2019) integrates a great number of physical processes in the estimated the linear trend using monthly mean residual environment and therefore can be a representative pa- sea level and they found the highest trend values was at rameters for monitoring the relationship between oce- Mina Salman about 3.4 0±0.98 mm/year and Abu Ali anic and atmospheric parameters. This study of sea-level Pier about 3.1±0.7 mm/year. Therefore, it is necessary variability is usually undertaken from hindcasts of the to study the sea level changes locally or regionally to un- last decades (Somot et al., 2006) and from the available derstand the various geophysical processes associated tide gauges and satellite altimeters data. Sea level chang- with the sea level variability. The Oman Sea, also called the Oman Gulf, is located at the north of the Arabian Smaeyl Hassanzadeh1,*( ) [email protected], Department of physics, University of Isfahan, 81746-73441, Isfahan, Iran,1 Department of phys- Sea (Figure 1). ics, University of Isfahan, 81746-73441, Isfahan, Iran The Gulf of Oman is strongly influenced by outflow from the Hormuz Strait. From fall through mid-spring, Mean Sea Level Variability along the Northern Coast of the Oman Sea and its Response to Monsoon and the North Atlantic Oscillation Index from Tide Gauge Measurement

Figure 1. Circulation of the Oman Sea and Northern Ara- bian Sea and the location of the Tide Gauge, Chabahar and Figure 2. Hourly sea level variability at Chabahar on the Jask (Johns et al., 1999) north coast of the Oman Sea satellite SSTs suggested a plume of outflow water owing Water level is measured using a mechanical float as a coastal current along the Oman and Emirate coast gauge manufactured by the Ott Companyin Germany. to Ras al Hadd at the edge of the Arabian Sea (Johns et Tidal records were monitored with 30 min sampling and al., 1999). This would imply that at least through part 1 cm resolution. The 30 minute values were converted of the year this outflow from the Hormuz Strait con- to hourly values using software developed by NCC. The sists of deep water layer and a modified surface layer tide gauges in the Iranian Tide Gauge network were that must together balance the inflow component. The connected to benchmarks established by NCC. NCC seasonal upwelling and circulation are also important did the precise leveling, i.e., they were responsible for along the coast of Iran in the Oman Sea. The seasonal determining the vertical distance between the bench and inter-annual variations in the circulation of the Gulf marks and the contact point at the tide gauge. The lev- of Oman is significant (Figure 1). The northern side of eling was performed several times every year. The NCC the Gulf of Oman has consistent upwelling associated benchmarks were connected to the Iranian Nation- with the SW monsoon along the Pakistani coast (Figure al Leveling Network. The tide gauge was calibrated by 1). Upwelling along the western, Iranian coast is more making its readings equal to the observations on a tide variable. pole installed beside the tidal station. All observations In 1995, for example, this coast was associated with are compared with tidal predictions. If the inspection upwelling filaments that moved to the west and even of the data revealed errors in observed heights, the data entered the outer edges of the Strait of Hormuz. Other were corrected by NCC. NCC used a ‘‘modified’’ Indian years suggest less extensive upwelling although there is Spring Low Water (ISLW) as chart datum. The quality of localized upwelling at the mouth of the Strait in all the the Iranian Tide Gauge network was approved by IOC/ years examined. In this study, data from two tide gauges GLOSS, Technical Report (Hareide, 2004). and meteorological parameters in the Oman Sea as well The monsoon and NAO indices were obtained from as data set of the gridded Ekman transport, the North web. Hourly tide gauge data from both Chabahar and Atlantic Oscillation (NAO) index and the Monsoon in- Jask stations were used in this study. An example of 1997 dex of the Indian Ocean were used. tide gauge record at Chahbahar is shown in Figure 2. The daily mean sea levels were calculated by averaging the Methodology hourly data of the whole day and are shown in Figure 3. The monthly sea level data available for Chabahar from Tide Gauge Data and Mean Sea Level 1993 to 2005 and for Jask from 1997 to 2005 are shown in Figure 4. Sea level was high in summer and was low in Hourly time series of tides were obtained from the Na- winter at both stations. Interannual variability was also tional Cartographic Center of Iran (NCC) and monthly apparent as this appeared relatively coherent between means of atmospheric parameters were gathered from stations. the Islamic Republic of Iran Meteorological Organiza- The annual mean of the sea level at both stations are tion. Atmospheric pressure, air temperature and wind shown in Figure 5. The highest mean sea level occurred data records were obtained from offshore stations at in 1999 and 2004 at Chabahar and in 2003 at Jask. The Chabahar and Jask (Figure 1).

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annual cycle was common to both tide gauges in the dorfer, 1988). northern coast of the Oman Sea. The seasonal variabil- Modelling Response and Sea Level Prediction ity had a close relation with the wind and atmospheric pressure. As the monthly data were not removed from The role of different climate forcings that might affect the this effect, a marked seasonally in monthly average was northern coast of the Oman Sea is statistically explored appeared. The behavior of the seasonal variability is pre- in this section. A linear regression and an Auto-Regres- sented in the Figure 6.The seasonal variability in both sive Integrated Moving Average (ARIMA) model were stations showed a gradual increase in the sea level be- fit to mean sea level and forcings as predictors for each tween February and June, the highest value in June and station and then were used to forecast sea level. The lowest in January (Figure 6). Then it began to decrease Ekamn transport was first decomposed in its PCs. The until December at Chabahar and until February at Jask. ARIMA models are AR models with differencing or The ranges were about 14 cm in Chahbar and about 20 moving average terms. The multiple regression was used cm in Jask. The major peak in June occurred during the to observe sea level, SL, as the dependent variable in the southwest monsoon. regression model of the following form: Monthly data on sea level, atmospheric pressure, air temperature, sea surface height (SSH), local wind, Monsoon and NAO Indices were analyzed. The month- Eq.(1) ly and yearly averages for each data set were computed and different statistical analyses were applied. In the first exploratory approach, correlations between sea level where independent variables P, T and W are the atmo- and each of the explanatory variables were produced by spheric pressure, temperature and wind, respectively, calculating the Pearson correlation coefficient, and cor- and a, b, and c are the coefficients.PC i is the ith PC of the responding P-values, between the time series. The em- Ekman transport and di is the corresponding coefficient, pirical orthogonal function (EOF) technique was used and N is the number of PCs included in the model. Ow- to define the patterns of spatial and temporal behavior of ing to possible significant correlation between different the Ekman transport. This technique was also referred sea level forcing inputs, the results from the univariate to the principal component analysis (PCA). The EOF model are likely to be affected. The statistical way to take decomposition was used to extract the dominant modes the correlation between input forcing into account was of spatial and temporal variability of the signal (Preisen- to perform a multivariate regression analysis of mean

Figure 3. Daily sea level variability at Chabahar (top) and Jask (Bottom) on the north coast of the Oman Sea

Research Paper 39 Mean Sea Level Variability along the Northern Coast of the Oman Sea and its Response to Monsoon and the North Atlantic Oscillation Index from Tide Gauge Measurement

Figure 4. Monthly sea level variability at Chabahar (top) Figure 5. Annual mean sea level at Chabahar (top) and and Jask (Bottom) on the north coast of the Oman Sea Jask (Bottom)on the north coast of Oman Sea

sea level on predictors. able Xt in time t, which can be written as: Multivariate regression was performed to confirm the relationship between sea level and forcing inputs. Eq.(4) Thus, regression model enabled to predict sea level using pressure, temperature, wind and Ekman transport forc- Thus, the forecast is: Eq.(5). ing. Autoregressive integrated moving average model of To calculate conditional expected values in the equa- degree p, d and q, ARIMA (p, d, q), was a combination of tion above one can assume that: AR and MA with differencing. Where,p is the number Et[Xt-j]=Xt-j, where Xt-j, in time t already known, one of autoregressive terms, d is the number of non-seasonal leaves without changes, differences, andq is the number of lagged forecast errors where Xt+j, still unknown are replaced in the prediction equation (Box and Jenkins, 1976). Lags with their forecasts of the differenced series appearing in the forecasting Et[et-j]=et-j, where e_(t-j), in time t already known, one equation are called “auto-regressive” terms, lags of the specifies as Eq.(6) forecast errors are called “moving average” terms, and The monthly data were used to compare the predic- a time series which needs to be differenced to be made tive ability of the multiple linear regression based on the stationary is said to be an “integrated” version of a sta- predictor variables and ARIMA model based on mean tionary series. For non-stationary data one should apply sea level time series. The results of the linear regression ARMA description to the series of differences of appro- model fitting for monthly mean sea level at Chabahar priate order, thus yielding ARIMA model (Autoregres- and Jask can be found in Figure 10. The results of the sive Integrated Moving Average). It can be written as: ARIMA model for monthly mean sea level series at Cha- bahar and Jask are also shown in Figure 10. The ARIMA model was based on time series of the mean sea level us- Eq.(2) ing the formula given above. Four ARIMA models with different orders were used to analyze the cases with two Stations for Chabahar from 1993 to 2005 and for Jask where, ∇d is a differential operator of degree d:∇ d from 1997 to 2005. The model parameters including the Xt=(Xt-Xt-1)d. Usually d = 0,1,2. A forecast generated by ARIMA coefficients denoted by p, d, and q are estimated the above process is given by: according to the Box-Jenkins methods (Box and Jenkins,

A forecast with least mean squared error, m periods 1976) and for Chabahar is shown in Table 1. ahead, is a conditional expected value of random vari- The optimal order of the ARIMA models was cho-

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Fig. 10. The predictions are in agreement with the relevant observations. We compared the forecasting performance of alternative models of the Mean Sea level. Four models are included in the comparison: the ARI- MA, models shown in Table 1. Forecasting performance was compared in terms of three criteria: R-Squared, root mean square error (RMSE) and mean absolute percentage error (MAPE). Table 1 summarizes the main diag- nostic and forecasting performance measures for the models. The model with the best overall performance is the ARIMA (1.1.1). In summary, the ARIMA (1,1,1) model has a number of desirable features. All its coefficients are statistically significant, most of them at the 1% level. It can be used to determine the mean sea level. Finally, it has the best forecasting performance of the models considered. Fig- ure 10 shows the similarity between fits of the linear regression and ARIMA models for Chabahar and Jask respectively. Both models predicted seasonality of the data for the sea level. The ARIMA models are more accurate for forecasting the mean sea level than the linear regression models. The two models predicted similar forecasts for sea level, but the greater accuracy for the ARIMA models are attributed to their dynamic nature and their ability to incorporate new information in forecasting by containing lagged terms of the forcing functions as explanatory variables.

Figure 6. Seasonal change of sea level at Chabahar (top) Results and Discussion and Jask (Bottom) on the north coast of Oman Sea Effect of Meteorological Parameters on Sea sen by Bayesian Information Criterion (BIC) (Sawa, Level Changes 1978). Minimum BIC values are used to determine the Sea level changes are mainly due to variations in the best performance of the ARIMA model because the BIC regional and global meteorological parameters. Atmo- places more emphasis on the parsimony of the model. spheric pressure variations and the thermal effect are Hence, ARIMA (1, 1, 1) and ARIMA (2, 1, 1), shown in the most important caused of sea level changes (Gomis, Table 1, were selected to forecast the mean sea level. et al., 2008 and Juncheng, et al., 2009 and Hosseinibalam, The predicted of ARIMA (1, 1, 1) models are shown in et al., 2007). The inverted barometer (IB) effect approx-

Table 1. Testing result of selected Autoregressive Moving Average (ARIMA) models for Chabahar

Structure BIC (Normalized) R-Squared RMSE MAPE

ARIMA (1, 1, 1) 0.566 0.887 0.684 0.178 ARIMA (2, 1, 1) 0.642 0.889 0.647 0.166 ARIMA (2, 1, 2) 1.199 0.942 0.490 0.109 ARIMA (1, 1, 2) 1.499 0.959 0.415 0.099 Note: BIC (Bayesian Information Criterion), RMSE (Root Mean Square Error, Mean Absolute Percentage Error (MAPE)

Research Paper 41 Mean Sea Level Variability along the Northern Coast of the Oman Sea and its Response to Monsoon and the North Atlantic Oscillation Index from Tide Gauge Measurement

Figure 7. Coherence between mean sea level and atmo- Figure 8. Coherence between mean sea level and air tem- spheric pressure of the Oman Sea for Chabahar station. perature of the Oman Sea for Chabahar station. Frequency Frequency is (cycles/month). is (cycles/month) imately related the oceanic response to the atmospheric upwelling (Figure 1). But, the ocean response to atmo- pressure fluctuations. In coastal areas the onshore-off- spheric pressure variations was close to the isostatic shore wind component can directly push water toward ones at Jask (r =-0.75), the response depended on the the shore or away from it. Usually the more dominant water flux dynamics at the Hormuz strait. effect was caused further offshore by the longshore wind In the open ocean and for periods longer than a few component, which can raise or lower the water level be- days, the sea level response to atmospheric pressure cause the Coriolis force caused transport to the right of forcing was close to an isostatic response (Fu and Pihos, the wind direction. Air temperature affected sea level by 1994; Gaspar and Ponte, 1997) and is well known by an warmth caused by the greenhouse effect. A sea level rise inverse barometer effect: a 1-mbar increased in atmo- could probably be caused by thermal expansion of the spheric pressure induced a sea level decrease of 1.01 cm. water column due to a decrease in water density caused Ducet et al. (1999) examined the validity of the inverse by it being warmed. In a first exploratory approach, cor- barometer approximation for the Black Sea mean lev- relation coefficients between sea level and each of the el using 5 years of Topex/POSEIDEN data. They found above parameters as explanatory variables were found very significant deviations from the inverse barometer by calculating the Pearson correlation coefficient, and response. They suggested that the deviation attributed corresponding P-values, between each time series. to narrowness of the Bosphorus Strait and it had limiting Atmospheric Pressure role in water exchange. Also the Mediterranean mean sea level to atmospheric pressure departed from a stan- The correlation coefficient (r) between monthly atmo- dard inverse barometer effect due to the limiting role of spheric pressure and monthly sea-level data for Cha- the Strait of Gibraltar (Candela, 1991). Alothman et al. bahar was (r =-0.35) with p-value 0.00 and for Jask is (2014) showed that at the Mina Sulman gauge there was (r =-0.75) with p-value 0.00. The p-values for all coef- no correlation between atmospheric pressure and sea ficients were less than 0.05, thus the Chabahar station level when the IB effect was subtracted from the data. had a weak negative correlation with the atmospheric Gomez-Enri et al. (2004) found that at mid and high pressure. The weak correlation coefficients meant that latitudes in the Indian Ocean. They suggested that the the Oman Sea mean level at Chabahar station did not relation between atmospheric pressure variations and respond to atmospheric pressure as an inverse barom- sea level fluctuation (BF) values indicated a response eter effect, or strong deviation from isostatic response near to the isostatic one; however, at low latitudes strong was observed. The non-barometric response to local at- deviations from the isostatic response were observed. mospheric pressure partly represented an influence of They observed some specific zones with values between sea level anomalies farther east due to the alongshore 0.60 and 0.40 cm/mb, where the oceanic response was component of wind stress and it generally forced a large clearly far from isostatic (south of India, Thailand Gulf, response than the onshore component. This was con- south of Indonesia and the east region of Madagascar), sistent with that expected from Ekman dynamics and contrary to that observed in the Atlantic Basin. Chabahr

42 SQU Journal of Agricultural and Marine Sciences, 2021, Volume 26, Issue 1 Hassanzadeh, Hosseinibalam

located in low latitude in the north of the Indian Ocean, The coherence analysis of the corresponding time se- therefore the deviation from the isostatic response was ries revealed an oscillatory behavior between mean sea expected. level and other variables. The annual peak was domi- Coherence Analysis between Atmospheric nant and contained the major energy in the time series Pressure and Sea Level and it can be seen for coherency of mean sea level and atmospheric pressure. The coherency between mean In order to study the response of mean sea level at the sea level and air temperature and wind indicated an an- Northern Coast of the Oman Sea to atmospheric pres- nual and a semiannual signal. There were some coher- sure more fully, coherence between two parameters was ency peaks at high and low frequencies which were not observed. Coherence between atmospheric pressure significant. The atmospheric pressure was minimum in and sea level is shown in Figure. 7. If the coherence val- summer while the temperature was maximum, and vice ue was unity, then the response of the sea level to the versa. It was obvious that the annual cycle was dominant atmospheric pressure should be inverse barometer. It in the atmospheric pressure and air temperature. There can be seen from Figure 7 that the coherence was unity. was also a weak semiannual cycle in the coherency of This means that in the northern coast the Oman Sea, wind. This can be due to the variability associated with mean sea level responded to atmospheric pressure as an the strong monsoonal forcing over the northern Indi- inverse barometer at low frequencies. It can be noticed an Ocean. The annual cycle was prominent in the wind that the low correlation (-0.35) between atmospheric speed. pressure and mean sea level found in the previous sec- Other Forces tion was due to the combination of other interrelated physical parameters, such as air temperature, steric ef- In this section, we consider the Ekman dynamic in order fect, evaporation, wind and Ekman transport, and this to examine the wind forcing and also, the external fac- played an important role in mean sea level changes, in- tors, NAO and Monsoon that may affect the sea level in terfering with the atmospheric pressure response. The this area need be investigated. Sea level anomalies were behavior of the response of the Oman Sea mean level to affected by the global climate change as well as by ab- atmospheric forcing at least in the northern coast was normal local climate changes (Church et al., 2006). For different from the one in the Persian Gulf because of the example, Barzandeh et al. (2018) showed that the sea Hormuz strait, which was pure inverse barometer (Has- level anomaly responds to wind-driven coastal upwell- sanzadeh et al., 2007). ing, as a regional phenomenon. The Ekman transport can be calculated in terms of wind stress, τ, sea water Atmospheric Temperature and Wind -3 density, ρw=1025 kg m , a dimensionless drag coeffi- -3 -3 The correlation coefficients (r) between monthly sea-lev- cient, Cd=1.4×10 , and air density, ρa=1.22 kg m , with el and air temperature and wind data for Chabahar were the following formula: 0.35 and 0.16, respectively. For Jask the correlation coefficient (r) between monthly sea-level and air tem- Eq.(7) perature and wind data were 0.70 and 0.39, respectively. Hereafter, we present the same coherence analysis as before, but between the mean level of the Oman Sea and air temperature and wind at Chabahar station. Eq.(8) Results of the coherence analysis are shown on Figure 8 for mean sea level and air temperature. The most strik- where, wind stress components are: ing point to notice was the strong coherence, around 0.6, 0.8 and 1.0, for different periods with an almost steady gain at about 2.0., which meant that temperature Eq.(9) had significant effect on mean sea level variations. The correlation between air temperature and atmospher- and ic pressure showed that these parameters were highly inter-correlated. The same coherence analysis with the Eq.(9) wind data was also performed, and this is shown in Fig- ure 9. Interestingly, it lead to a much lower value at lower ƒ is the Coriolis parameter defined as twice the vertical frequencies and noisier coherence at high frequencies, component of the Earth’s angular velocity, Ω, about the which meant that wind had no direct significant effect local vertical given by ƒ=2Ωsin(θ) at latitude θ. Finally, on mean sea level variations. The wind effect would yield the x subscript co rresponds to the zonal component water level proportional to wind stress, because of the and the y subscript to the meridional one. EOF analysis associated Ekman transport and Ekman upwelling along was used to study for spatial and temporal linked vari- the Iranian coast around the Chabahar Gulf as it can be ability by analyzing mean sea level and Ekman transport. seen from Figure 1. This method partitioned the temporal variance of the

Research Paper 43 Mean Sea Level Variability along the Northern Coast of the Oman Sea and its Response to Monsoon and the North Atlantic Oscillation Index from Tide Gauge Measurement

Figure 9. Coherence between mean sea level and wind of the Oman Sea for Chabahar station (Frequency, cycles/ month) highly correlated data into a small number of orthogonal spatial patterns called eigenvectors and corresponding orthogonal time coefficients. These Eigen functions have a series of coefficients in time that modulate them are ranked in decreasing order according to the percent of the variance. In general, each mode has an associated Figure 10. Comparison of fitted linear regression and variance, non-dimensional spatial pattern, and dimen- ARIMA models with the observation sional time series. The set of orthogonal functions are derived from the data itself. The first eigenvector is vir- contributions of linear change and the NAO to sea-level tually the same as an overall average pattern of Ekman variability in the northern coast of the Oman Sea were transport in this case. The Ekman transport input data investigated in this study. steps on n grid points. The monthly NAO indices of each year was used, The initial EOF analysis was performed on the Ek- which are represented by the sea-level difference be- man transport. The results of the analysis demonstrated tween Azores atmospheric pressure High and Icelandic that over 48.90% of the mean square of the data was con- Low. The correlation coefficients (r) between monthly tained in the first function and that 87.16% of the mean NAO and monthly sea-level data for Chabahar was r square was captured by the first four modes of east-west =-0.05 and for Jask it was r =-0.07. The p-values for all component. Also, it demonstrated that over 48.20% of coefficients were less than 0.05, thus both stations had a the mean square of the data was contained in the first weak negative correlation with the NAO. mode and that 94.70% of the mean square the data was Correlation coefficients between time series of Indi- captured by the first fourth of the north-south compo- an summer monsoon index and sea-level was calculated. nent of the Ekman transport. The correlations coefficients, r =0.26 p = 0.12, for Cha- The correlation coefficients (r) of sea level with- Ek bahar and r =-0.07 p = 0.73, for Jask were obtained. Thus man transport were found for both stations. Significant the sea-level at these tide gauges was little affected by correlation coefficients, r=-0.70 (p-value=0.00) for Cha- Indian Ocean Monsoon. The sea level change appears bahar, and r=-0.40 (p-value =0.00) for Jask. The North to response to the Ekman transport which would be ex- Atlantic Oscillation (NAO) was recognized as the fore- pected from the wind stress regimes. Sea level response most mode of variability in the North Atlantic region to NAO and Monsoon was negligible compared with with major impacts in Europe and further afield (Hur- the response to regional forcings. EOF analyses was per- rell, 1995; Cullen and deMenocal, 2000) especially in the formed to find relations between the sea level and the winter. Sea level in Black Sea was significantly correlated Ekman transport. In the following, the Ekman transport with winter NAO only in spring (Tsimplis et al., 2004), variability is discussed in terms of the four time series of but sea level in the Persian Gulf was not correlated with the leading PC mode. the winter NAO index (Hassanzadeh et al., 1995). The

44 SQU Journal of Agricultural and Marine Sciences, 2021, Volume 26, Issue 1 Hassanzadeh, Hosseinibalam

Conclusion Journal of Climatology 20: 853–863. Ding X, Zheng D, Chen Y, Chao J, Li Z. (2001). Sea level The correlation analysis showed that the response of the change in Hong King from tide gauge measurements Oman Sea mean level was deviated from inverse barom- of 1954-1999. Journal of Geodesy 74: 683-689. eter. The coherence analysis revealed a significant coherence value between sea level and atmospheric pressure Eshghi N, Barzandeh A, Hosseinibalam F, Hassanzadeh, and did not validate the non-inverse barometer effect. S. (2020). Investigating dynamic and static aspects of Other causes of sea level variation in this region, such as regional sea level changes in the north-western Indi- steric effects associated with non-propagating seasonal an Ocean, Bollettino di Geofisica Teorica e Applicata variations or the existence of baroclinic Rossby and Kel- 61(2): 249-270. vin waves in the Indian Ocean. It seemed that impor- Fu LL, Pihos G. (1994). Determining the response of sea tance can be explained by the inverse barometer devia- level to atmospheric pressure forcing using TOPEX- tion. The departure from inverse barometer was due to rPOSEIDONdata. Journal of Geophysical Research the combination of other interrelated physical process- 99: 24633–24642. es, such as air temperature, steric effect, evaporation, Gaspar P, Ponte R. (1997). Relation between sea level wind and Ekman transport, which played an important and barometric pressure determined from altimeter role in mean sea level changes and interfering with the data and model simulations. Journal of Geophysical atmospheric pressure response. Sea level response to Research 102: 961–971. NAO and Monsoon was negligible compared with the Gomez-Enri J, Villares P, Brouno M, Catalan M. (2004). response to regional forcings. Evidence of different ocean responses to atmospheric The linear regression model was fitted to the mean sea pressure variations in the Atlantic, Indian and Pacific level and forcing functions and ARIMA (2,0,2) models Basin as deduced from ERS-2 altimeter data. An- used various lagged values to forecast mean sea level. nales Geophysicae 22: 331-345. The accuracy of the forecasted using ARIMA is better than linear regression models. Gomis D, Ruiz S, Sotillo GM, Alvarez-Fanjul E, Terra- das J. (2008). Low frequency Mediterranean sea level Acknowledgement variability: The contribution of atmospheric pressure and wind. Global and Planetary Change 83: 215-229. The authors gratefully acknowledge the support of the Hassanzadeh S, Kiasatpour A, Hosseinibalam F. (2007). Department of Research and Technology of University Sea-level response to atmospheric forcing along the of Isfahan for this work. Moreover, we thank the De- north coast of Persian Gulf. Meteorology and Atmo- partment of Oceanography and Prof. G. Weatherly, for spheric Physics 95: 223-237. hosting visits to Florida State University, Tallahassee, Haredide D. (2004). Iranian Tide Gauge Network IOC/ FL, when this work was carried out. GLOSS, Technical Report (http://www.pol.ac.uk/ References psmsl/reports.gloss/general/). Hosseinibalam F, Hassanzadeh S, Kiasatpour A. (2007). Alothman GO, Bos, MS, Fernandes, RMS, M.E. Ayhan, Interannual variability and seasonal contribution of ME. (2015). Sea level rise in the north-western part thermal expansion to sea level in the Persian Gulf. of the Arabian Gulf. Journal of Geodynamics 81: Deep-Sea Research I 54: 1474–1485. 105–110. Hurrell JW. (1995). Decadal trends in the North Atlantic Barzandeh A, Eshghi N, Hosseinibalam F, and Hassan- Oscillation: Regional temperatures and precipitation. zadeh S. (2018). Wind-driven coastal upwelling along Science 269: 676–679. the northern shoreline of the Persian Gulf. Bollettino Johns EW, Jacobs AG, Kindle CJ, Murray PS, Carron M. di Geofisica Teorica e Applicata 59: 301-312. (1999). Arabian Marginal seas and Gulf. Report of a Box GEP, Jenkins GM. (1976). Time series analysis: Workshop held at Stennis Space Center, Mississippi, forecasting and control. Holden-Day, San Francisco, USA. USA. Juncheng Z, Jianli Z, Ling D, Peiliang L, Lei L. (2009). Candela J. (1991). The Gibraltar Strait and its role in the Global sea level and thermal contribution. Journal of dynamics of the Mediterranean Sea. Dynamics of At- Ocean University of China 8(1): 1-8. mospheres and Oceans 15(3-5): 267-299. Preisendorfer RW. (1988). Principal component analysis Church JA, White NJ, Hunter JR. (2006). Sea-level rise in meteorology and oceanography. Developments in at tropical Pacific and Indian Ocean Islands. Global Atmospheric Science, Elsevier, Netherlands, 425 pp. Planetary Change 5: 155-168. Sawa T. (1978). Information criteria for discriminating Cullen HM, deMenocal PB. (2000). North Atlantic influ- among alternative regression models. Econometrica ence on Tigris-Euphrates stream flow. International 46:1273–1291.

Research Paper 45 Mean Sea Level Variability along the Northern Coast of the Oman Sea and its Response to Monsoon and the North Atlantic Oscillation Index from Tide Gauge Measurement

Siddig NA, Al-Subhi, A. M., Alsaafani, M. A. (2019). Tsimplis MN, Josey SA, Rixen M, Stanev EV. (2004). On Tide and mean sea level trend in the west coast of the the forcing of sea-level in the Black sea. Geophysical Arabian Gulf from tide gauges and multi-missions Research Letters 109: C08015. satellite altimeter. Oeanologia 218: 1-11. Wunsch C. (1972). Bermuda sea level in relation to tides, Stammer D, Cazenave A, Ponte RM, Tamisiea, ME. weather, and baroclinic fluctuations. Reviews of Geo- (2013). Causes for contemporary regional sea level physics 10: 1–49. changes. Annual Review of Marine Science 5: 21-46. Somot S, Sevault F, Deque M. (2006). Transient climate change scenario simulation of the Mediterranean Sea for the 21st century using a high-resolution ocean. Climate Dynamics 27: 851–879.

46 SQU Journal of Agricultural and Marine Sciences, 2021, Volume 26, Issue 1 Journal of Agricultural and Marine Sciences 2021, 26(1): 47–52 DOI: 10.24200/jams.vol26iss1pp47-52 Reveived 21 April 2020 Accepted 22 Nov 2020 Research Paper Protective effect ofOxalis corniculate and Pteropyrum scoparium Leaf Extracts against Azoxymethane-induced oxidative stress and colon carcinogenesis Mostafa I. Waly*, Mohammed Al-Khusaibi, Nejib Guizani التأثري الوقائي ملستخلص أوراق النبااتت الربية العمانية ) السيداف و احلميضة( ضد اإلجهاد التأكسدي الناجم عن تسرطن القولون يف حيواانت التجارب مصطفى وايل*, حممد اخلصييب, جنيب قيزاين

Abstract. Oxalis corniculate and Pteropyrum scoparium are two edible wild Omani plants with known preventive effects on various human diseases, yet their therapeutic role in colon cancer has not been studied yet. Azoxymethane (AOM) is a common oxidizing agent that induces colon cancer in experimental animal models. In the current study, the protective effect of Oxalis corniculate and Pteropyrum scoparium leaves extracts against AOM-induced cancer and oxidative stress in rat colon was examined. Sixty Sprague-Dawley rats were randomly divided into 6 groups (10 rats/group). Control group was fed a standard diet; the AOM-treated group was fed a standard diet and received an intraperitoneal injection of AOM at a dose of 30 mg/kg body weight for each rat. The other four groups received an intra-gastric intubation of Pteropyrum scoparium or Oxalis corniculate leaves extracts (0.1 mg extract/1 mL water/ day) in the absence or presence of AOM injection. After 8 weeks, all rats were sacrificed and the colon tissues were dissected for Aberrant Crypt Foci (ACF) enumeration of cancer lesions development, and for measurements of glutathione (GSH), total antioxidant capacity (TAC), and DNA oxidative damage. The results in this study showed that the AOM-injected rats showed significant increased level of DNA oxidative damage, lower levels of GSH and TAC, and higher ACF as compared to the control group. Oxalis corniculate and Pteropyrum scoparium leaf extracts significantly suppressed the oxidative damage associated with AOM injection and mitigated its carcinogenic effect in rat colon. Both Oxalis corniculate and Pteropyrum scoparium leaf extracts acted as potent antioxidants and combat the AOM-associated oxidative stress and colon carcinogenesis. The data from this study suggest that dietary supplementation of these two wild plants might be applied as a therapeutic agent for colon cancer treatment. Keywords: Antioxidants, Colon cancer, Omani Wild Plants, Oxidative stress املســتخلص:النبااتت العمانيــة )الســيداف Pteropyrum) scoparium و )احلميضــة Oxalis ) corniculateهــي نبــااتت تنمــو يف الربيــة و صاحلــة لــأكل و أيضــاهلمــا ًآاثر وقائيــة معروفــة ضــد العديــد مــن األمــراض املزمنــة ، ومــع ذلــك مل يتــم دراســة دورمهــا العالجــي يف ســرطان القولــون حــى اآلن. فمــن املعــروف أن العوامــل املؤكســدة تســبب مــرض ســرطان القولــون لذلــك يف الدراســة احلاليــة ، مت فحــص التأثــر الوقائــي ملســتخلصات أوراق النبــااتت العمانيــة ضــد الســرطان الناجــم عــن اإلجهــاد التأكســدي يف قولــون الفئــران كنمــوذج حليــواانت التجــارب. ولقــد اشــتملت التجربــة علــى ســتون فــأراً مــن ســاللة ســ اغرب داويل ومقســمة إىل 6 جمموعــات )10فئــران / جمموعــة( كاأليت: اجملموعــة الضابطــة و اجملموعــة املعاجلــة بســرطان القولــون )الــي تلقــت حقنــة مــن مركــب AOM جبرعــة 30 جمــم / كجــم مــن وزن اجلســم لــكل فــأر( بينمــا تلقــت اجملموعــات األربــع األخــرى مســتخلصات أوراق نبــات الســيداف أو احلميضــة يف غيــاب أو وجــود مركــب AOM. اســتمرت التجربــة ملــدة 8أســابيع ، و بعــد هــذه املــدة مت التضحيــة جبميــع الفئــران ومت تشــريح أنســجة القولــون مــن أجــل رصــد تطــور األورام الســرطانية يف القولــون ، ومت ايضــاًقيــاس مركــب اجللواتثيــون ) ( GSH، والقــدرة اإلمجاليــة ملضــادات األكســدة ) (، TACوكذلــك أضــرار أكســدة احلمــض النــووي يف مجيــع أنســجة القولــون جلميــع الفئــران. ولقــد أظهــرت نتائــج هــذه الدراســة أبن الفئران احملقونة بـ AOM أظهرت زايدة ملحوظة يف مســتوى ضرر أكســدة احلمض النووي ، واخنفاض مســتوايت GSH و TAC ، وارتفاع نســبة األورام الســرطانية ابلقولــون مقارنــة ابجملموعــة الضابطــة. بينمــا أظهــرت النبــااتت العمانيــة املســتخدمة أتثــر دفاعــي ضــد الضــرر التأكســدي املرتبــط حبقــن AOM وخففــت أيضــا ًمــن التأثــرات املســرطنة يف القولــون. ختامــا ًفــإن كالًمــن أوراق نبــات الســيداف و احلميضــة تعمــل كمضــادات أكســدة قويــة وتكافــح اإلجهــاد التأكســدي املرتبــط بـــسرطان القولــون. و تشــر البيــاانت الــواردة مــن هــذه الدراســة إىل أن هــذه النبــااتت الربيــة العمانيــة ميكــن اســتخدامها كمكمــل غذائــي عالجــي ملكافحــة مــرض ســرطان القولــون. الكلمات : املفتاحيةمضادات األكسدة ، سرطان القولون ، النبااتت الربية العمانية ، اإلجهاد التأكسدي Introduction wild plants of Oman are two edible plants (Oxalis corniculate, commonly known as Hamd, and Pteropyrum man has around 1200 species of wild plants, scoparium, commonly known as Sidaf) which have ther- many of which are reported to be used in tradi- apeutic properties based on their bioactive constituents tional medicine (Divakar et al., 2016). However, (Al Attabi et al., 2015). Oxalis corniculate is short-lived Oless than 10% of these plants have been screened for their perennial plant growing only 5 – 10 cm tall but spread- medicinal use (Waly et al., 2014). Among the important ing at the roots to form a mat of growth 30 cm or wider, and it is harvested from the wild for food, medicine and Mostafa I. Waly*( ) [email protected], Department of Food Science and Nutrition, College of Agricultural and Marine Sciences, various other commodities (Divakar et al., 2016). Ptero- Sultan Qaboos University, Muscat, Oman pyrum scoparium has been used for generations as an additive to Omani traditional dishes; it is considered as Protective effect of Oxalis corniculate and Pteropyrum scoparium Leaf Extracts against Azoxymethane-induced oxidative stress and colon carcinogenesis an important herbal drug for treating various diseases, Phytochemical contents of plants leaves extracts such as diabetes, fever, skin diseases and inflammation Folin-Ciocalteu assay was used to determine the total (Divakar et al., 2016). phenol content (Suresh et al., 2016). The total pheno- Colon cancer is the third most common type of can- lic content of samples was expressed as mg Gallic Acid cer in terms of incidence and the fourth in cause of death Equivalents (mg GAE/100 g sample). The total flavo- world-wide (WHO, 2020). Clinical studies continue to noids content was determined using Catechin as stan- support the notion that oxidative stress is involved in the dard, and the results were expressed as mg Catechin (mg etiology of colon cancer (Afshari et al., 2019). Oxidative of CAE/100 g sample). (Suresh et al., 2016). stress is a condition in which oxidants level is counter- Evaluation of the free radical scavenging balancing the antioxidant-dependent cellular defense capacity of plant leave extracts mechanisms and contributes among other factors to the pathogenesis of cancer (Monteiro et al., 2020). It The capacity of each one of the two plants leaves extract has been suggested that higher intake of antioxidants to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) free is associated with a lower risk of oxidative stress-me- radical was performed by a spectrophotometric meth- diated colonic carcinogenesis (Waly et al., 2014). odology. Briefly, each plant leave extract at different Azoxymethane (AOM) induces cancer in the co- concentrations (10 - 100 µg/mL), were mixed with stable lon and rectum of animal models by causing oxida- DPPH radical in methanolic solution (0.3 mL of DPPH tive damage to DNA and its associated gene muta- radical solution 0.5 mM in 3 mL ethanol). When DPPH tion and adductions (Waly et al., 2015). Glutathione reacts with an antioxidant compound, which can donate (GSH) is the major intracellular antioxidant which hydrogen, it is reduced. The changes in color (from deep scavenged oxidants, and accordingly an increase in violet to light yellow) were read [Absorbance (Abs)] at its level is crucial to combat oxidative stress-mediat- 517 nm after 30 min of reaction using a UVVIS spec- ed colon carcinogenesis (Padmanabhan et al., 2019). trophotometer (DU 800; Beckman Coulter, Fullerton, Total antioxidant capacity (TAC) reflects the cellu- CA, USA). Controls contained all the reaction reagents lar redox status (enzymatic and non-enzymatic sys- except plant leaves extracts or 2,6-di-tert-butyl-4-hy- tems), and TAC impairment activity was reported in droxytoluene (BHT), the positive control. The free animals’ models for colon cancer (Waly et al., 2016). radical scavenging capacity of different samples were There are negligible published reports that identi- expressed as %DPPH inhibition, a higher %free radical fy the in vivo antioxidant potential properties of Ox- scavenging activity value indicates a higher antioxidant alis corniculate and Pteropyrum scoparium in relation activity and it was calculated as follows: to colon cancer pathogenesis. Therefore, this study was undertaken to evaluate these two Omani plants % DPPH inhibition = [(Absorbance of control–Absor- for their phytochemical contents and antioxidant bance of sample)/ Absorbance of control] X 100 properties in an experimental model of colon cancer. Methods Animal and Experimental Design The protocol used in this study was conducted in ac- Chemicals cordance with international laws and policies and approved by the Animal Ethics Committee at the Sultan AOM (catalogue # A5486) and sodium chloride phys- Qaboos University (SQU/AEC/2019-2020/8). Sixty male iological solution (catalogue# 52455) were purchased Sprague Dawley rats weighing 150 ± 5 gm were obtained from Sigma-Aldrich Co. (St. Louis, Missouri, USA). from the animal breed at the animal house facility, Sul- tan Qaboos University, Muscat, Oman. The rats were Plant Collection and Identification housed in individual cages at standard conditions, and they were fed a standard diet and given water ad-libitum. Three kg of each plant Oxalis( corniculate and Pteropy- The rats were randomly divided into 6 groups (n=10 rum scoparium) were collected from their natural habi- rats/group). Control group was fed a standard diet and tat and immediately washed of dust and impurities using also received a single intraperitoneal injection of 0.9% tap water. The plants were kept at room temperature un- physiological saline in week one; AOM-injected group der shade until they are completely dried, and the leaves was fed a standard diet and a single intra-peritoneal dose of each plant were ground to fine powder by use of elec- of AOM (30 mg/kg body weight) dissolved in 0.9% phys- tric grinder (Moulinex AR1043-UK0). The powdered iological saline in week one. The other four groups were samples were macerated in aqueous methanol, and the fed a standard diet and received intra-gastric intubation filtrates were then evaporated using rotary evaporator. of 1 mL of either Oxalis corniculate or Pteropyrum sco- The resulting crude extract (50 g dry solids) was stored parium leaves extracts (100 µg extract/mL sterile dis- at - 40 ºC till use for subsequent experiments. tilled water/day) in the presence or absence of AOM injection. The therapeutic dose used effective doses for the

48 SQU Journal of Agricultural and Marine Sciences, 2021, Volume 26, Issue 1 Waly, Al-Khusaibi, Guizani

two plants leaf extracts were determined based on the 30 minutes of incubation at 37oC, the samples and stan- results of DPPH assay. The plant leaf extracts were given dards were read in a fluorescence plate reader at 380/460 on daily basis at the same timing early morning, through- nm. GSH content was determined by comparison with out the 8 weeks study period. Body weight was record- values from a standard curve using freshly prepared ed weekly for the entire duration of the experiment. GSH and normalized to the protein content of the as- Animal Sacrifice sayed colon tissue homogenates. Total Antioxidant Capacity (TAC) Measurements After 8 weeks, the rats were fasted overnight, anesthe- tized with a lethal dose of a cocktail containing ketamine A colorimetric method (Randox Assay Kit, Randox (1 mg), xylazine (5 mg), and acepromazine (0.2 mg) and Laboratories Ltd, UK) was used to measure the TAC. then sacrificed. The colon tissue of each rat was excised The assay is based on the incubation of samples with for histo-pathological examination of any cancer lesions 2, 2’-azino-di-[3-ethylbenzthiazoline sulphonate (6)] development, and for biochemical measurements of ox- diammonium salt (ABTS) with a peroxidase (metmyo- idative stress indices. globin) and hydrogen peroxide to produce the radical Colon Preparation cation ABTS+ which has a relatively stable blue-green color that is measured at 600 nm. Antioxidants present The colons were carefully removed from rats and were in the assayed colonic mucosal tissue homogenate sam- kept on a glass plate in ice jackets. The colons were then ples inhibit the oxidation of ABTS to ABTS+ (cause sup- opened longitudinally, rinsed with ice-cold physiologi- pression of the color production) to a degree that is pro- cal saline, and sectioned longitudinally into two equal portional to their concentration. The assay results were halves. The first half was fixed flat in 10% buffered- for normalized to the protein content of the assayed colon malin (Fisher Scientific, Fair Lawn, NJ) between two fil- tissue homogenates. ter papers for one week before Aberrant Cypt Foci (ACF) enumeration. Meanwhile, the other half was rinsed with DNA Oxidative Damage Assay ice-cold physiological saline and was immediately homogenized in 10 mL of 100 mM potassium phosphate The DNA was isolated from the colon tissues homog- buffer (pH 7.2) by a glass-Teflon homogenizer with an enates and the DNA oxidative damage was measured ice-cold jacket and centrifuged at 6,000 g at 4°C for 60 using 8-oxo-7,8-dihydro-20-deoxyguanosine (8-oxod- minutes. The resulting supernatant was used for deter- Guo) assay as described earlier (Suresh et al., 2017). The mination of protein, GSH and TAC measurements. 8-oxodGuo and 2dG in the DNA were detected using an ESA Coulochem II electrochemical detector in line with Aberrant Cypt Foci (ACF) Enumeration a UV detector. Fixed colons were stained with 0.2% methylene blue in Statistical analysis Kreb’s ringer bicarbonate buffer for 20 minutes in a Petri dish and rinsed with physiological saline. After staining, The results are expressed as means ± standard deviation the colons were placed with the mucosal surfaces up on (SD). The statistical analysis was performed using one- a slide, to be examined with a light microscope under way analysis of variance (ANOVA) followed by Tukey’s 40X magnification and scored for ACF. In brief, the ACF test and a P value of less than 0.05 was considered signif- were distinguished from normal crypts by their darker icant (GraphPad Prism version 5.03; GraphPad Software stain, enlarged and slightly elongated size, thick epithe- Inc. San Diego, CA). lial lining, slightly elongated cryptal opening and often slit shaped. The total number of ACF was recorded for Results all examined colons (Waly et al., 2014). Polyphenols and flavonoids Protein Content Analysis Oxalis corniculate leaf extract had as higher total poly- The Protein content of colon tissues was as- phenol contents as compared to that of Pteropyrum sco- sayed by the method of Lowry et al. (1951) us- parium leaf extracts (320±13 and 252±10 mg GAE/100 g ing bovine serum albumin as standard and pro- sample, respectively, P < 0.05). A similar significant dif- tein content was expressed as mg/ml of sample. ference in the flavonoid contents was observed for both

GSH Measurements Oxalis corniculate and Pteropyrum scoparium leaves extracts (245±9 and 117±8 mg of CAE/100 g sample, re- Aliquots of supernatant (100 µL) were transferred to spectively, P < 0.05). fresh Eppendorf tubes and 2 µL of monochlorobimane (25 mmol/L) and 2 µL of glutathione-S-transferase re- DPPH agent were added, as provided by a commercial kit (Bio- As presented in Figure 1, the Oxalis corniculate and vision, Mountain View, CA, USA, Catalog # K251). After Pteropyrum scoparium leaves extracts inhibited DPPH

Research Paper 49 Protective effect of Oxalis corniculate and Pteropyrum scoparium Leaf Extracts against Azoxymethane-induced oxidative stress and colon carcinogenesis formation in a dose-dependent manner (10-100 µg/mL), and it was observed that Oxalis corniculate leaves extract exhibited a higher inhibition rate as compared to the Pteropyrum scoparium leaf extracts, P < 0.05. The plateau of the effective doses for both extracts was 50- 100 µg/ml. Therefore, the effective dose, 100 µg/mL, was

Figure 2. Changes in body weight of rats supplemented with Oxalis corniculate and Pteropyrum scoparium leaves extracts in the presence or absence of azoxymethane (AOM) carcinogen. Animals in the six groups were examined for the changes in their body weight every week for 8 weeks. *Significantly lower as compared to control group, P< 0.05. Values without superscript are not significantly different as compared to control group. Figure 1. Scavenging effect of Effects ofOxalis corniculate and Pteropyrum scoparium leaves extracts and 2,6-di-tert-butyl-4-hydroxytoluene (BHT) against 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical formation. *Significantly higher as compared toPteropyrum scoparium leaves extracts, P< 0.05.

used for subsequent animal in vivo studies. Body Weight Gain of Animals No mortality occurred in any group, and the body weight for each rat was recorded weekly for the whole duration of the experiment and as demonstrated in Fig- ure 2. The body weight increased gradually throughout Figure 3. Effects ofOxalis corniculate and Pteropyrum the experimental period for all the groups. However, all scoparium leaves extracts on aberrant crypt foci (ACF) rats in the AOM-injected group showed a consistent de- development in control and azoxymethane (AOM)-increase in body weight throughout week 2 to week 8 as jected groups. *Significantly higher than the control group, P<0.05. **Significantly lower than AOM-injected compared to control groups, P < 0.05. It was notable that group, P<0.05. Values without superscript are not signifi- the supplementation of AOM-injected group with ei- cantly different as compared to control group, P>0.05. ther Oxalis corniculate or Pteropyrum scoparium leaves extracts compensated for the weight loss due to AOM (Figure 3). injection, P < 0.05.

AOM-Associated Oxidative Stress ACF Enumeration It has been observed that the Oxalis corniculate, or All the AOM-injected rats developed the ACF; mean- Pteropyrum scoparium leaves extracts supplementation while the concomitant supplementation of AOM-inject- to the AOM-injected group resulted in combating the ed groups with Oxalis corniculate or Pteropyrum scopar- observed AOM-induced oxidative stress by restoring ium leaves extracts has abrogated the ACF production, the level of depleted GSH to a level that is comparable P < 0.05. The histopathological examination of colonic to the control group, P > 0.05 (Figure 4). The same trend tissues of rats supplemented with Oxalis corniculate, was observed for the protective effects of the plants ex- or Pteropyrum scoparium leaves extracts displayed the tracts supplementation on abrogating the AOM-medi- normal architecture of colon tissue as compared to the ated effect on TAC, (Figures 5). As illustrated in Figure control group and did not show any ACF development

50 SQU Journal of Agricultural and Marine Sciences, 2021, Volume 26, Issue 1 Waly, Al-Khusaibi, Guizani

6, AOM caused oxidative damage to the DNA in the colon tissues of rat injected with AOM and the difference was significantly higher than the control group, P<0.05, meanwhile, the plants extract supplementation showed a significant reduction in the DNA damage in the AOM-injected group, P < 0.05.

Figure 6. DNA oxidative damage (8-hydroxydeoxygua- nosine, 8-OHdG) in colonic tissue homogenates of rats supplemented with Oxalis corniculate and Pteropyrum scoparium leaves extracts in the presence or absence of azoxymethane (AOM) carcinogen. *Significantly lower as compared to control group, P<0.05. **Significantly higher than AOM injected group, P<0.05. Values without superscript are not significantly different as compared to control group, P>0.05.

Discussion Figure 4. Glutathione (GSH) measurements in colon- AOM injection acted as a colon cancer inducing agent in ic tissue homogenates of rats supplemented with Oxalis a mechanism that involves oxidative stress as evidenced corniculate and Pteropyrum scoparium leaves extracts by the significant reduction of the intracellular GSH lev- in the presence or absence of azoxymethane (AOM) carcinogen.*Significantly lower as compared to control group, el, impairment of TAC, and increase in the level of DNA P<0.05. **Significantly higher than AOM injected group, oxidative damage as compared to control non-treated P<0.05. Values without superscript are not significantly dif- group. The present study elucidated the role of Oxalis ferent as compared to control group, P>0.05. corniculate and Pteropyrum scoparium leaves extracts in alleviating AOM-induced oxidative stress and its associated colon carcinogenesis.

We reported that rats injected with AOM developed oxidative stress in the colon tissues as evidenced by GSH depletion, reduction of TAC and increased DNA oxidative damage, as well as histo-pathological changes which manifested carcinogenic effect in the examined colonic tissues. This is consistent with previous reports from our research group which indicated that AOM injection in rats resulted in a reduction in the colonic redox cellular status (Waly et al., 2014). However, Oxalis corniculate and Pteropyrum scoparium supplementation has suppressed the oxidative damage associated with AOM injection and mitigated its carcinogenic effect. These findings suggested that these two Omani wild plants can have a colon-protective effect against AOM-induced oxidative stress and its associated colon carcinogenesis.

Figure 5. Total antioxidant capacity (TAC) measurements The findings in this work are consistent with the well in colonic tissue homogenates of rats supplemented with documented role of natural plants in the treatment and Oxalis corniculate and Pteropyrum scoparium leaves extracts in the presence or absence of azoxymethane (AOM) prevention of chronic diseases, including cancer (Wang carcinogen. *Significantly lower as compared to control et al., 2020). In particular, Oxalis corniculate and Ptero- group, P<0.05. **Significantly higher than AOM injected pyrum scoparium have wide medicinal applications, as group, P<0.05. Values without superscript are not significant- previous studies have shown that Oxalis corniculate and ly different as compared to control group, P>0.05. Pteropyrum scoparium are rich in phytonutrients and

Research Paper 51 Protective effect of Oxalis corniculate and Pteropyrum scoparium Leaf Extracts against Azoxymethane-induced oxidative stress and colon carcinogenesis prevent generation of cellular oxidative stress and in- Journal of Biological Chemistry. 193(1): 265-75. flammation, hence offers a novel therapeutic approach to Monteiro HP, Rodrigues EG, Amorim Reis AKC, Longo prevent oxidative stress-induced pathogenesis (Al-Atta- LS Jr, Ogata FT, Moretti AIS, da Costa PE, Teodoro bi et al., 2015). Our study documented that Oxalis cornic- ACS, Toledo MS, Stern A. (2019). Nitric oxide and ulate and Pteropyrum scoparium scavenged the oxida- interactions with reactive oxygen species in the de- tive stress-induced colon carcinogenic effect in the used velopment of melanoma, breast, and colon cancer: A experimental model, these results address the primary redox signaling perspective. Nitric Oxide 89: 1-13. prevention of oxidative stress in relation to colon cancer. Omara T, Kiprop AK, Ramkat RC, Cherutoi J, Kagoya S, Moraa Nyangena D, Azeze Tebo T, Nteziyaremye P, Conclusion Nyambura Karanja L, Jepchirchir A, Maiyo A, Jema- AOM administration resulted in oxidative stress and tia Kiptui B, Mbabazi I, Kiwanuka Nakiguli C, Nak- increased ACF formation in the examined colon tissues abuye BV, Chepkemoi Koske M. (2020). Medicinal in rats. Oxalis corniculate and Pteropyrum scoparium Plants Used in Traditional Management of Cancer in are rich in total phenolic and flavonoid compounds, Uganda: A Review of Ethnobotanical Surveys, Phy- and their supplementation have significantly abrogated tochemistry, and Anticancer Studies. Evidence Based the AOM-mediated oxidative stress, and combated the Complementary Alternative Medicine 2020: 1-26 AOM-induced AFC formation. Our study suggests that (Article ID 3529081). dietary supplementation of these two wild plants might Padmanabhan S, Waly MI, Taranikanti V, Guizani N, Ali be applied as a therapeutic agent for prevention against A, Rahman MS, Al-Attabi Z, Al-Malky RN, Al-Mas- colo rectal cancer rather than its treatment as abberant kari SNM, Al-Ruqaishi BRS, Dong J, Deth RC. (2019). crypt foci are more of premalignant lesions and dyspla- Folate/Vitamin B12 Supplementation Combats Oxi- sia, however it is essential to conduct further studies to dative Stress-Associated Carcinogenesis in a Rat Mod- evaluate the colon-protective effect of these two Omani el of Colon Cancer. Nutrition Cancer 71(1):100-110. wild plants in human-based clinical trials. Suresh S, Waly MI, Rahman MS, Guizani N, Al-Kindi MAB, Al-Issaei HKA, Al-Maskari SNM, Al-Ruqa- Acknowledgment ishi BRS, Al-Salami A. Broccoli (Brassica oleracea). The authors declared no conflicts of interest. This- re (2017). Reduces Oxidative Damage to Pancreatic Tis- search was supported by a grant obtained from the Col- sue and Combats Hyperglycaemia in Diabetic Rats. lege of Agricultural and Marine Sciences, Sultan Qaboos Preventive Nutrition and Food Science 22(4): 277-284. University, Muscat, Oman (IG/AGR /FOOD /20/01). An Waly MI, Al-Ghafri BR, Guizani N, Rahman MS. (2015). oral presentation of this manuscript was presented at Phytonutrient Effects of Date Pit Extract against the 21st ISANH Middle East World Congress in Muscat, Azoxymethane--Induced Oxidative Stress in the Rat Sultan Qaboos University on March 4-5, 2019. The pre- Colon. Asian Pacific Journal of Cancer Prevention sentation entitled: Medicinal plants from chemopreven- (8): 3473-3477. tion to identification of potential biomarkers for colon Waly MI, Al Alawi AA, Al Marhoobi IM, Rahman MSh. cancer. Red Seaweed (Hypnea bryodies and Melanothamnus somalensis) Extracts Counteracting Azoxymeth- References ane-Induced Hepatotoxicity in Rats. Asian Pacific Journal of Cancer Prevention 2016 Dec 1; 17(12): Afshari K, Haddadi NS, Haj-Mirzaian A, Farzaei MH, 5071-5074. Rohani MM, Akramian F, Naseri R, Sureda A, Gha- naatian N, Abdolghaffari AH. (2019). Natural fla- Waly MI, Al-Rawahi AS, Al Riyami M, Al-Kindi MA, vonoids for the prevention of colon cancer: A com- Al-Issaei HK, Farooq SA, Al-Alawi A, Rahman MS. prehensive review of preclinical and clinical studies. (2014). Amelioration of azoxymethane induced-car- Journal of Cell Physiology 234(12): 21519-21546. cinogenesis by reducing oxidative stress in rat colon by natural extracts. BMC Complementary Alterna- Al-Attabi Z, AlMamri R, Al AbdAslam K. (2015). Antiox- tive Medicine 14: 1-10. idant potential properties of three Wild Omani plants against hydrogen peroxide-induced oxidative stress. Wang J, Seyler BC, Ticktin T, Zeng Y, Ayu K. (2020). An Canadian Journal of Clinical Nutrition (2): 16-22. ethnobotanical survey of wild edible plants used by the Yi people of Liangshan Prefecture, Sichuan Prov- Divakar MC, Al-Siyabi A, Varghese SS, Rubaie MA. ince, China. Journal of Ethnobiology and Ethnomed- (2016). The Practice of Ethnomedicine in the North- icine 16: 1-27. ern and Southern Provinces of Oman. Oman Medical Journal (4):245-52. WHO. 2020. World Health Organization report on cancer: setting priorities, investing wisely and pro- Lowry OH, Rosebrough NJ, Farr AL, Randall RJ. (1951). viding care for all. ISBN 978-92-4-000129-9 (elec- Protein measurement with the Folin phenol reagent. tronic version). ISBN 978-92-4-000130-5 p. 28-30.

52 SQU Journal of Agricultural and Marine Sciences, 2021, Volume 26, Issue 1 Journal of Agricultural and Marine Sciences 2021, 26(1): 53–56 DOI: 10.24200/jams.vol26iss1pp53-56 Reveived 11 May 2020 Accepted 30 Nov 2020 Technical notes Microbiological Assessment of Locally Dried Fish in Oman: Technical Note

Aaisha K. Al-Saadia, Abdulrahim M. Al-Ismaili a,*, Mohammed Al-Ruzeikib, Ismail M. Al-Bulushib

التقييم امليكروبيلوجي لألمساك اجملففة حمليا ًيف عمان: مالحظة فنية عائشة الساعدي1، عبد الرحيم اإلمساعيلي1،*، حممد الرزيقي2، إمساعيل البلوشي2

Abstract. The presence of microorganisms is one of the major factors affecting the quality of dried fish. In this project, a number of analytical tests were used to verify the presence of biochemical contamination in dried fish, as well as to propose an engineering solution to reduce the incidence of these contaminations. Two types of fish samples (anchovy and shark) were collected from two local markets (Buraimi and Seeb). The analyzed parameters included Total Fungal Count (TFC), Total Viable Count (TVC) and enumeration of Escherichia coli (E. coli), Staphylococcus aureus and Coliforms species in dried fish. The results indicated that the anchovy collected from Seeb market had the highest TVC and TFC (TVC= 5.59×105 cfu/ ml, TFC= 3.60×104 cfu/ml) compared to all other samples. It could be recommended to dry fish under more hygienic conditions using solar drier instead of direct drying on beach sands. Keywords: Solar drying, fish drying, fish contamination, dried fish, microbial assessment املســتخلص: يعتــروجــود الكائنــات احليــة الدقيقــة أحــد أهــم العوامــل الرئيســية الــي تؤثــر علــى جــودة األمســاك اجملففــة، ويف هــذه الدراســة مت اســتخدام عــدد مــن األختبــارات التحليليــة للتحقــق مــن وجــود امللــواثت البيلوجيــة يف األمســاك اجملففــة ،حمليــاً وكذلــك مت اقــراح حــل هندســي يعمــل علــى تقليــل وجــود هــذه امللــواثت، ومــن أجــل ذلــك فقــد مت مجــع عينــات لنوعــن مــن األمســاك ومهــا األنشــوجة والقــرش )تســمى حمليــا القاشــع و العــوال( مــن ســوقي حمليــن ومهــا البميــي والســيب، وقــد مت حتليــل وجــود العوامــل التاليــة: العــدد الكلــي للفطــرايت )TFC( والعــدد الكلــي احليــوي ) ( TVC وتعــداد بكتــراي E-coli و بكتــراي Staphylococcus aureus وبكتــراي الكوليفــورم يف األمســاك اجملففــة. 4 5 وقــد أظهــرت النتائــج أن العــدد الكلــي للفطــرايت ) g5.59×10 cfu/ml( والعــدد الكلــي احليــوي ) g3.60×10 cfu/ml( يف األنشــوجة الــي متمجعهــا مــن ســوق الســيب كان أكثــر منهــا يف العينــات األخــرى. وبنــاء علــى وجــود هــذه امللــواثت يف األمســاك اجملففــة فإننــا نوصــي بتجفيــف األمســاكيف ظــروف صحيــة أفضــل، ونشــجع علــى اســتخدام اجملففــات الشمســية بــدال مــن التجفيــف املباشــر علــى رمــال الشــاطىء. الكلمات :التجفيف املفتاحيةالشمسي ، جتفيف األمساك ، تلوث األمساك ، األمساك اجملففة ، التقييم امليكروبيلوجي.

Introduction and the remaining 7% is sold after being dried, salted or smoked (FAO, 2019). In 2018, the total fish production ish is the main foodstuff around many countries in of Oman was about 553 thousand tons which was 59% the world because of its high protein content and more than the production in the previous year (MAF, nutritional value. However, in the hot climates, fish 2018). In the same year, fish export constituted 44% of Fperishes quickly and it is common to increase their shelf the total production (about 245 thousand tons). life using different techniques such as drying, smoking The traditional drying process of fish causes the loss and salting (Sultana et al., 2010). In the Gulf region, of 30-40% of dried fish due to eating by dogs, birds, cats, Oman is the largest fish producer (FAO, 2019) and it has and rats, especially during winter when drying takes more than 150 kinds of fish and crustaceans (Belwal et about a week (Sablani et al., 2002). Indeed, this factor al., 2015). Most of the fish in Oman are sold fresh (93%) causes a reduction on the revenue of dried fish, which also suffers from the contamination by sand particles. Abdulrahim M. Al-Ismailia,*( ) [email protected]; abdrahim@ hotmail.co.uk, aDepartment of Soils, Water and Agricultural Engineer- It was reported that sand contamination causes high b ing, Sultan Qaboos University, 123, Al-Khoud, Sultanate of Oman, De- concentration of ash in the dried fish (Al Ghabshi et al., partment of Food Science and Nutrition, Sultan Qaboos University, 123, Al-Khoud, Sultanate of Oman 2012). In addition, sun-dried fish may become unhealthy Microbiological Assessment of Locally Dried Fish in Oman: Technical Note

when it is attached by insects and larva. It was found that Enumeration of Bacteria some fishermen apply insecticides to avoid this kind of The samples were stored in a freezer at -40ºC until used attacks (Bala & Mondol, 2001). for the microbial analysis. Then, the samples were ana- The presence of microorganisms affects the quality lyzed for 3 types of bacteria; E. coli, staphylococcus au- of dried fish. Some studies showed that bacteria, molds, reus and coliforms as total colony-forming units (cfu/ml) and yeasts are potential microorganisms that usually using different agar media, as explained below. contaminate dried fish (Akwuobu et al., 2019). Therefore, it is important to determinate the microbiological qual- Enumeration of E. coli, Staphylococcus aureus ity of dried fish. The aim of this study was to verify the and Coliforms presence of microbiological contamination in dried fish For E. coli, about 50 g of fish sample was taken, cut into collected from selected local markets; and to propose an small pieces and mixed together. Then, a stomacher bag engineering solution to reduce these contaminations. was placed in a beaker and only 25 g of the mixed pieces were placed in the bag. After that, 225 ml of diluent was Methodology added to the stomacher bag and blended for 1 min to -1 Two common types of traditionally dried fish in Oman achieve a homogenized mixture at 10 dilution. Then, -2 -3 were collected namely; anchovy and shark (locally called dilutions of 10 and 10 were prepared. -1 -2 Owal) from two different places; Buraimi and Seeb fish For plating, 0.1 ml from each tube of the 10 , 10 , -3 markets. The anchovy samples were collected from and 10 diluents were transferred to duplicate plates of packaged and unpackaged conditions from the two plac- Tryptone Bile X-Glucuronide Agar (TBXA) plate asepti- es. About 500 g was purchased from each place. They cally. Then, the mixture was spread using alcohol flamed were placed in zipped bags and transported to the Food spreading from the highest dilution to the lowest dilution -3 -1 Microbiology laboratory at the College of Agricultural (i.e. 10 to 10 ). Finally, incubation was done for all plates and Marine Sciences, SQU for analysis. aerobically at 35ºC for 24 h and only blue or green colonies were counted and reported (cfu/g) using Equation 1. Media Preparation For staphylococcus aureus, the diluents were pre- All media were prepared according to Al Bulushi (2017) pared as explained earlier for the enumeration of E. coli and each test was prepared using the media as men- in dried fish. For plating, molten Baird-Parker agar were tioned in Table 1. After preparing the media for each used instead of molten TBX Agar. Finally, black colonies test, it was mixed with distilled water. Then, each mix- were counted and reported (cfu/g) using Equation 1. ture was poured in a bottle and autoclaved at 121ºC for For coliform species, the diluents were prepared as 2-2.5 h. After autoclaving, 15 ml of the agar media was explained earlier for the enumeration of E. coli in dried placed in Petri dishes and cooled at room temperature to fish. For plating, 1 ml from each diluent was transferred solidify the media (Al Bulushi, 2017). to sterile petri dishes. For each dilution, two plates were used. Over a period of 15 min, approximately 12 Total Fungal Count and Total Viable Count ml of molten VRB Agar at 44-47ºC was added. The me- From each sample, 25 g was placed in a sterile stomach- dium with the inoculum was carefully mixed by hori- er bag, and 225 ml of maximum recovery diluent was zontal movements (pour plate method) and the medi- added in the stomacher bag (Interscience/France) to um was allowed to cool down. Finally, the dishes were achieve 1/10 (10-1) dilution. Then, 10-2 and 10-3 dilutions incubated for 24±2 h at 35ºC and only pink colonies were prepared. For plating, 0.1 ml (100 µl) was trans- were counted and reported (cfu/g) using Equation 1. ferred from each tube of the 10-1, 10-2, and 10-3 dilution Moisture Content and Water Activity mixtures to duplicate plates of the Potato Dextrose Agar (PDA) plate aseptically. Then, the mixture was spread The moisture content was determined by oven-drying o using alcohol flamed spreading from the highest dilution the samples at 105 C for 24 h (Ullah et al. 2016). The wa- to the lowest dilution (i.e. 10-3 to 10-1). All plates were inter activity (aw, unit less) of the sample was determined cubated aerobically at an ambient temperature of nearly using a water activity meter. The correlation of moisture 23ºC for 3-5 days. After that, the colonies on plates were content and water activity with the analyzed microbial counted and reported (cfu/g) using Equation 1. counts was studied using STATA 13.0 (StataCorp, USA) For Total Viable Count, all procedures were the same at α = 0.05. as Total Fungal Count except the differences with the type of agar used (SPCA), temperature (35ºC) and period of incubation of the plates (48 h).

54 SQU Journal of Agricultural and Marine Sciences, 2021, Volume 26, Issue 1 K. Al-Saadi, M. Al-Ismaili, Al-Ruzeiki, M. Al-Bulushi

Table 1. The media used for each biological test.

Tests Media Manufacturer/country

Total Fungal Count Potato Dextrose Agar (PDA) Sigma-Aldrich/USA Total Viable Count Standard Plate Count Agar (SPCA) Sigma-Aldrich/USA The diluent Maximum Recovery Diluent Sigma-Aldrich/USA Enumeration of E. coli Tryptone Bile X-Glucuronide Agar (TBXA) Sigma-Aldrich/USA Enumeration of Staphylococcus aureus Baird Parker Agar (BPA) Sigma-Aldrich/USA Enumeration of Coliforms species Violet Red Bile Agar (VRBA) Sigma-Aldrich/USA

Results and Discussion directly on the sand is more susceptible to the contamination by dust, insects, and sand (Bremner, 2002). In Microbial Contamination addition, the stability of microbial growth in dried fish depends on how much moisture they contain during The anchovy collected from Seeb market had the highest processing and storage stages (Logesh et al., 2012). Rain 5 4 TVC and TFC (5.59×10 , 3.60×10 cfu/ml, respectively) and humid conditions hamper sun-drying by increas- as compared to all other samples (Table 1). In addition, ing the moisture content of dried fish and made them the presence of 3 species of bacteria; E. coli, staphylo- susceptible to blowfly larvae attacks (Kleih et al., 2003). coccus aureus, and coliforms was detected in anchovy samples more than in shark samples as collected from Techniques to Avoid the Contamination the two markets. Previous studies reported that anchovy The presence of microbes in dried fish presents a health had more contamination than the allowable levels (Aliya hazard that needs to be prevented. To avoid the contam- et al., 2018; Kumar et al., 2017). It was observed that the ination of sand, dirt, and animals, the process of drying moisture content and water activity of the shark from has to be done quickly using drying shelves, which can Buraimi market were the highest among all samples help to keep dried fish away from these sources of con- (30.37% and 0.74, respectively). In the case of dried fish tamination (Ward & Beyens, 2015). Solar dryers, like storage, Bala and Mondol (2001) stated that microbial greenhouse tunnel dryers and forced convective solar growth was inhibited when the moisture content was dryers can also help to avoid physical and atmospher- reduced to 25% and particularly mold growth could be ic-driven contamination and they can accelerate the dry- avoided when the moisture content was not more than ing process (Sahu et al., 2016; Seerangurayar et al., 2019). 15%. However, this was not the case in this study, as re- These types of solar dryers are highly recommended as ported in Table 2, which could be related to the types of they protect dried fish from many sources of contami- contaminations present in the samples used in this study. nation like rain, humid environment, dust, insects and Although, the moisture content of anchovy was lower animals as well as increase the drying rate. than 15%, large values of TVC and TFC were observed.

Table 2. Results obtained from different tests.

Xm TVC=APC TFC E. coli S.aureus Coliforms Fish Type (Market) aw (%) (cfu/ml) (cfu/ml) (cfu/ml) (cfu/ml) (cfu/ml) Shark (Seeb) 23.66 0.64 1.05×103 2.50×102 0 6.96×103 0 Shark (Buraimi) 30.37 0.74 1.05×104 2.00×103 0 1.33×104 0 Anchovy (Seeb) 14.54 0.69 5.59×105 3.60×104 4.77×102 1.64×106 1.78×103 Anchovy (Buraimi) 14.15 0.65 1.29×105 3.70×103 6.00×102 2.27×105 2.82×102

The detected microbes in the analyzed samples could Conclusion have come from several sources, namely, unhygienic In this article, we verified the presence of microbiolog- handling of fish during drying and storage, and birds ical contamination in two types of dried fish (anchovy and animals’ droppings. In addition, long time open- and shark) available in local markets (Seeb and Buraimi). sun drying under high humidity environments enhances The major issue that affects the quality and safety of dried the growth of microorganisms (Sablani et al., 2002). In fish is the contamination caused by bacteria and fungi. general, major sources of contamination include pollut- Results from this study evidenced the presence of fungi ed coastal water and soil, dust and unhealthy treatment and three species of bacteria; E. coli, staphylococcus au- practices (Ginigaddarage et al., 2018). Placing the fish

Technical notes 55 Microbiological Assessment of Locally Dried Fish in Oman: Technical Note

reus and coliforms. The microbial contamination in an- Kleih, U., Alam, K., Dastidar, R., Dutta, U., Oudwater, chovy samples was more than in shark samples collected N., & Ward, A. (2003). Livelihoods in coastal fishing from the two local markets. To avoid the contamination communities, and the marine fish marketing system mentioned above, we recommend using solar dryers for of Bangladesh. Synthesis of participatory rural ap- fish drying instead of open-sun drying, as they protect praisals in six villages, and assessment of the market- the dried fish from different types of contamination and ing system (NRI report no. 2712). speed up the drying process. Kumar GP, Xavier KM, Nayak BB, Kumar HS, Ven- kateshwarlu G, Balange AK. (2017). Effect of differ- References ent drying methods on the quality characteristics of Pangasius hypophthalmus. International Journal of Akwuobu CA, Antiev WS, Ofukwu RA. (2019). Fungal Current Microbioly and Appllied Science 6: 184-195. Contaminants of Smoke-Dried Fish Sold in Open Markets in Makurdi, Benue State, North-Central Ni- Logesh AR, Pravinkumar M, Raffi SM, Kalaiselvam M. geria. Food and Nutrition Sciences 10(3): 290-297. (2012). An investigation on microbial screening on salt dried marine fishes. Journal of Food Resource Al Bulushi IM. (2017). The Handbook of Food Microbiolog- Science 1(1): 15-21. ical Analytical Methods. Nova Science Publishers, Inc. MAF. (2018). Statistical Book on Fishery. Ministry of Al Ghabshi A, Al-Khadhuri H, Al-Aboudi N, Al-Gharabi Agriculture and Fishery, Oman. S, Al-Khatri A, Al-Mazrooei N, Sudheesh PS. (2012). Effect of the freshness of starting material on the final Sablani SS, Rahman MS, Mahgoub O, Al-Marzouki A. product quality of dried salted shark. Advance Jour- (2002). Sun and solar drying of fish sardines. Pro- nal of Food Science and Technology 4(2): 60-63. ceedings of the International Drying Symposium, p 1662-1666. Aliya A, Sudheesh PS, Nasser AA, Umkalthoum AK, Wafaa AE, Humaid AK, Mahmood AM, Alia AZ, Sahu TK, Jaiswal V, Singh AK. (2016). A review on solar Waleed AR, Mahmood AM. (2018). Microbiological, drying techniques and solar greenhouse dryer. IOSR chemical and nutritional quality and safety of salted Journal of Mechanical and Civil Engineering (IOSR- cured fishery products from traditional dry fish pro- JMCE) 13: 31-37. cessing plants in the Sultanate of Oman. Food Re- Seerangurayar T, Al-Ismaili AM, Jeewantha LJ, Al-Habsi search 2(3): 279-86. NA. (2019). Effect of solar drying methods on color Bala BK, Mondol MR. (2001). Experimental investiga- kinetics and texture of dates. Food and Bioproducts tion on solar drying of fish using solar tunnel dryer. Processing 116: 227-239. Drying technology 19(2): 427-436. Sultana N, Hossain MT, Siddique MP, Uddin MI, Dina Belwal R, Belwal S, Al Jabri O. (2015). The fisheries of MA, Farhana Z. (2010). Microbial quality of dried Oman: A situation analysis. Marine Policy 61: 237-248. fish of different areas Chittagong and Mymensingh districts of Bangladesh. International Journal of Bremner HA. (2002). Safety and Quality Issues in Fish Bioresearch 2(8): 1-5. Processing. Woodhead Publishing and CRC press, New York. Ullah N, Hazarika P, Handique PJ. (2016). Biochemical Quality Assessment of Ten Selected Dried Fish Spe- FAO. (2019). Fishery and Aquaculture Country Profiles. cies of North East India. International Advanced Re- [http://www.fao.org/fishery/facp/OMN/en (accessed search Journal in Science, Engineering and Technol- 11 October 2020) ogy 3(1): 30-33. Ginigaddarage PH, Surendra IH, Weththewa WK, Ari- Ward A, Beyens Y. (2015). Fish handling, quality and yawansa KW, Arachchi GG, Jinadasa BK, Hettiarachchi processing: training and community trainers manual. KS, Edirisinghe EM. (2018). Microbial and chemical qual- Smartfish Working Papers. 001. Port Louis, Commis- ity of selected dried fish varieties available in Sri Lankan ion del’Ocean Indien, Mauritius. market. Sri Lanka Journal of Aquatic Sciences 23(1).

56 SQU Journal of Agricultural and Marine Sciences, 2021, Volume 26, Issue 1 Journal of Agricultural and Marine Sciences 2021, 26(1): 57–61 DOI: 10.24200/jams.vol26iss1pp57-61 Reveived 14 Oct 2020 Accepted 05 Dec 2020 Technical notes Correlation between Sensory and Instrumental Textural Attributes of Date Palm (Phoenix dactylifera L.) fruits: Technical Note

Vandita Singh1,*, Mohammad Shafiur Rahman2, Nejib Guizani2, Hakikulla Shah3

االرتباط بني السمات املقيمة حسيا و ابألجهزة لفاكهة شجرة النخيل )التمر( ).Phoenix dactylifera L(: مالحظة فنية فانديتا سينغ1 ، * ، حممد شفيور الرمحن2 ، جنيب غيزاين2 ، حقيق هللا شاه3

Abstract. Food industries are constantly looking for optimum instrumental methods that can consistent- ly estimate sensory textural qualities of food products. Monitoring texture using instrumental methods is cheaper over time than maintaining a sensory quality panel. However, a good correlation between sensory and instrumental textural attributes is highly needed. In the present research, we aimed to report the correlation between instrumental and sensory textural attributes of date fruit varieties. Specifically, Instru- mental Texture Profile Analysis(TPA) and sensory textural attributes were correlated. We found significant correlations between sensory and instrumental TPA attributes of date fruit varieties and this suggests a great promise for developing quality control. Keywords: Date fruits, Sensory analysis, Instrumental texture, Phoenix dactylifera, Correlation املســتخلص:تبحث الصناعــات الغذائيــة ابســتمرار عــن األســاليب اآلليــة املثلــى اللــي متكنهــا مــن تقديــر جــودة صفــات الرتكيــب النســيجي احلســي للمنتجــات الغذائيــة. تعــد متابعــة النســيج ابســتخدام األجهــزة أرخــص مــع مــرور الوقــت مــن احلفــاظ علــى لوحــة ملقيمــي اجلــودة احلســية. ومــع ذلــك، مــن الضــرورة أن يوجــد ارتبــاط وعالقــة جيــدة بــن الســمات احملــددة حســيا و تلــك احملــددة ابألجهــزة. هدفنــا يف البحــث احلــايل هــو حتديــد االرتبــاط بــن الســمات املقيمــة حســيا و ابألجهــزة لنســيج أصنــاف مــن فاكهــة التمــر. و ابلتحديــد، كان هنــاك ارتبــاط بــن الســمات احملــددة حســيا و ابســتخدام اجلهــاز املخصــص لتحليــل النســيج ) ( TPAلفاكهــة التمــر و قــد كان هــذا االرتبــاط ذو أمهيــة إحصائيــة؛ ممــا يعــي أن هنــاك إمكانيــة لتطويــر مراقبــة اجلــودة ابســتخدام األجهــزة. الكلمات املفتاحية: مثار التمر، التحليل احلسي، النسيج اآليل، فينيكس داكتيليفريا )Phoenix dactylifera ،( االرتباط

Introduction it is also useful to improve the instrumental method for better pairing with sensory results (Aguirre et al., 2018; exture, defined as the sensory manifestation of Kurotobi et al., 2018). Date Fruits (DFs) are popular sta- food structure and the way this structure reacts ple food in the Middle East as well as, source of income to the forces applied and it represents the junc- for many families. The DFs are commercially import- Ttion of all the mechanical, geometric, and superficial ant and sold as fresh (i.e. Rutab) and dried (i.e. Tamar) attributes of a product, sensed through mechanical, tac- (Chandrasekaran and Bahkali, 2013). Hence, there is a tile, visual, and hearing receptors (Rahman, 2009; Rah- great amount of research in the field of DF including man et al., 2020). Assessment of textural attributes by their phytochemical contents (Al-Hinai et al., 2013; Essa either instrumental method (i.e. Textural Profile Anal- et al., 2019; Hossain et al., 2014; Singh et al., 2013; Singh ysis, TPA) and or by sensory methods is of great inter- et al., 2012). The growing food industry is also utilizing est in food technology (Rahman, 2019). The correlation the DFs to produce variety of products (e.g. biscuits, fla- obtained between sensory and instrumental texture vored dairy products, and chocolate). Texture is a criti- measurements could be used to assess quality control cal property of the fruit that can dominate quality of the parameters, consumers liking and their overall accept- product. In the past decade few studies have focused on ability for product development or improvement, and the instrumental texture of the DF (Al-Hinai et al. 2013). Vandita Singh1,*( ) [email protected], 1Department of Food The growing date industries demands for assessing the Science and Human Nutrition, College of Applied and Health Sci- sensory analysis of date fruits. 2 ences, A’Sharqiyah University, P. O. Box 42, Ibra, Oman, Depart- The fruits quality is assessed based on texture, flavor, ment of Food Science and Nutrition, College of Agricultural and Marine Sciences, Sultan Qaboos University, Muscat, Oman, 3De- color, and nutritional properties (Ismail et al., 2008).The partment of Biological Science and Chemistry, College of Arts and sensory textural characteristics are recognized as crit- Sciences, University of Nizwa, Post Box 33, PC 616, Nizwa, Oman, ically important factors of food choice (Grunert, 2015; Correlation between Sensory and Instrumental Textural Attributes of Date Palm (Phoenix dactylifera L.) fruits: Technical Note

Rahman, 2019). Generally, sensory methods are more Instrumental Texture Profile Analysis (TPA) useful in developing new products and defining product Different instrumental textural attributes (i.e. hardness; standards in comparison with instrumental method (i.e. adhesiveness; springiness; cohesiveness; resilience; TPA). Although sensory analysis (i.e. descriptive meth- gumminess; chewiness; elasticity) of date fruits samples od) require a panel training and maintenance, however, were measured earlier (Singh et al., 2013). Briefly, all ex- it is not only time-consuming and expensive, but also periments were conducted at room temperature (25 ± demands proper reference standards for calibration 2°C). One pitted date was divided into two halves and (Joyner, 2018). Hence, attempt have been made to estab- one side was placed over another. It was then pressed to lish the relationship or predictive model between sen- prepare a flat slab. A typical force-time graph of two-cy- sory attributes and instrumental parameters (Li et al., cle instrumental TPA for different date samples was an- 2020; Taniwaki et al., 2010). alyzed (Singh et al., 2013). There is continuous industrial search for certain instrumental techniques for forecasting the sensory tex- Textural Sensory Analysis tural attributes of final processed products and/or even The textural sensory attributes (i.e. hardness; adhesive- raw materials (Barbieri et al., 2018; Li et al., 2020; Rah- ness; springiness; cohesiveness; resilience; gumminess; man et al., 2020; Taniwaki et al. 2010). Instrumental chewiness; elasticity) of date fruits were assessed by 20 methods have advantage, as they tend to offer precise trained-panels (SQU students) using descriptive test. results (Rahman et al., 2020). Generally, instrumental The panelists were trained on how to assess the defined results can be directly linked to chemical and physi- attributes with respect to the provided references. The cal properties permitting the investigator to achieve a training proceeds with the actual samples. More details mechanistic understanding of experimental differences. were presented in the earlier published work (Singh et Instruments are more sensitive to small alterations be- al. 2015). tween samples and capable to detect trends in quality loss before it can be detected by humans (Mestres et al., Statistical Analysis 2019; Rahman et al., 2020; Yu et al., 2017). Instruments Experimental data were analyzed using PAST Software. can be used to yield large amounts of data without ob- Multivariate Analysis (MVA) was performed to deter- jection, making them excellent screens in quality control mine the correlations between sensory and instrumen- operations (Yu et al., 2017). The data on the instrumental textural characteristics of DFs (Hammer et al., 2001). tal and sensory textural attributes of 9 date fruit varieties MVA including Pearson’s (i.e. linear) and Spearman’s as a function of their physicochemical characteristics correlation matrix were run using all sensory and instru- were published earlier (Singh et al., 2013; Singh et al., mental textural attributes. Linear and Spearman’s cor- 2015). Hence, we aimed in this paper to report the correlations were used to determine the relationships be- relation between the instrumental and sensory textural tween each variable for the P values ≤ 0.05 and P≤ 0.10. attributes of date fruit varieties. Materials and methods Results and Discussion Nine batches of DFs at Tamar stage (Figure 1) with dif- The instrumental forces for texture analysis were cor- ferent quality levels were obtained from the local market related with sensory attributes. Correlation results at Muscat. All the samples were stored at -20˚C until showed that instrumental hardness were significantly used for the analysis (Singh et al., 2013). correlated with sensory hardness, along with adhesive-

Figure 1. Photos of date samples used for the textural studies

58 SQU Journal of Agricultural and Marine Sciences, 2021, Volume 26, Issue 1 Singh, Shafiur, Guizani, Hakikulla Shah

ness, springiness, cohesiveness, chewiness and elasticity relations. Similar results were reported in the case of (P<0.05) in both linear and spearman’s correlation, and cooked rice, where instrumental adhesiveness did not with sensory resilience (P<0.1) linearly (Table 1). In the show any correlation with sensory stickiness (P>0.05) literature, often instrumental hardness are significant- (Prakash et al., 2005). The poor correlation between sen- ly correlated with the sensory hardness (Prakash et al., sory and TPA springiness was not surprising since simi- 2005; Tao et al. 2020). Similar correlation was report- lar results were reported recently (Nishinari et al., 2019). ed for Instrumental hardness with sensory hardness in Moreover, instrumental gumminess showed linear cooked rice (P<0.05) (Prakash et al., 2005). Significant correlation with sensory hardness and elasticity (P<0.05) correlations were also observed in the cases of instru- and with sensory adhesiveness, springiness, cohesive- mental hardness and springiness with sensory hardness ness and chewiness (P<0.10). Instrumental chewiness and springiness (P<0.001) when 21 different foods sam- was significantly correlated with sensory chewiness ples, for examples caramel, egg white, cream cheese, (P<0.05) and with all others sensory attributes except corn muffin were considered (Meullenet et al. 1998). In gumminess. In the case of cereal snack bars, senso- the case of baked product, Young’s modulus correlated ry attributes of chewiness, firmness, and crumbliness with sensory elasticity. Conversely, instrumental cohe- showed very high degrees of correlations (P<0.001) with siveness and chewiness did not show correlations with the instrumental TPA (Kim et al., 2009). Similarly, Chi- sensory cohesiveness and chewiness (P>0.05). Howev- nese moon cake showed instrumental hardness, chewi- er, correlations of these two attributes were significant- ness, and stickiness highly correlated with the sensory ly improved when the variables were transformed with data (Jia et al., 2008). logarithmic function (i.e. non-linearity) (P<0.05) (Meul- Instrumental Elasticity 1 was correlated with senso- lenet et al., 1998). We observed similar results for our in- ry elasticity in both linear and spearman’s correlation. It strumental cohesiveness, which did not show any linear was linearly correlated with sensory cohesiveness chew- correlation however, correlation was improved in spear- iness (P<0.05), hardness, adhesiveness (P<0.1). Further, man’s correlation with sensory cohesiveness (P<0.1), correlation with sensory hardness (P<0.05), springi- chewiness and resilience (P<0.05). ness (P<0.1) was improved in Spearman’s. Instrumen-

Table 1. Coefficients of Linear and Spearman correlation between sensory and instrumental texture measurements for nine varieties of Date fruits

Instrumental Sensory attributes attributes Linear correlation Spearman’s correlation HA AD SP CO RE GU CH ES HA AD SP CO RE GU CH ES HA * * * * * * NS * * * * * * NS NS * * AD NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS SP NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS CO1 NS NS NS NS NS NS NS NS NS NS NS * * * NS * NS RE * * * * * * NS * * * * * * * * NS * * GU1 * * * * * * * NS NS * * * * * NS * NS NS NS NS * * CH1 * * * * * NS * * * * * * * NS * * E1 * * * * NS * NS NS * * * NS * * NS NS NS NS * E2 NS NS NS NS NS NS NS NS NS NS * * NS NS * NS NS * p<0.05; ** p<0.10; NS: No significant correlations Note: HA: hardness; AD: adhesiveness; SP: springiness; CO: cohesiveness; RE: resilience; GU: gumminess; CH: chewiness; E: elasticity

Further, our results showed that instrumental resil- tal Elasticity 2 did not show any linear correlation with ience was correlated with sensory resilience (P>0.10) respective sensory attributes however, in spearman cor- and with other sensory attributes, such as hardness, relation, it was related to sensory gumminess (P<0.05), adhesiveness, springiness, cohesiveness, chewiness and springiness (P<0.1). Out of eight sensory attributes elasticity in both Pearson’s and Spearman’s correlations. studied, four were well predicted with their respective Instrumental adhesiveness and springiness did not show instrumental measurements, while others i.e. adhesive- significant correlations (P>0.10) with the any of the sen- ness, cohesiveness, springiness and gumminess were not sory attributes in both Pearson’s and Spearman’s cor- correlated with their respective instrumental attributes.

Technical notes 59 Correlation between Sensory and Instrumental Textural Attributes of Date Palm (Phoenix dactylifera L.) fruits: Technical Note

This may be due to the difference in compression plate Essa MM, Singh V, Guizani N, Manivasagam T, Then- size and test sample in TPA, which may lead to variance mozhi AJ, Bhat A, Ray B, Chidambaram SB. (2019). in major cutting or shearing of the sample (Kim et al., Phoenix dactylifera l. Fruits date fruit ameliorate ox- 2009). The lack of cutting or shearing may lower the cor- idative stress in 3-np intoxicated pc12 cells. Interna- relation values between instrumental and sensory attri- tional Journal of Nutrition, Pharmacology, Neurolog- butes (Battaglia et al., 2020; Paula and Conti-Silva, 2014). ical Diseases 9(1): 41-47. Grunert KG. (2015). The common ground between sen- Conclusion sory and consumer science. Current Opinion in Food Science 3: 19-22. In the current study, sensory and instrumental textural attributes were correlated. The evaluation of texture Hammer Ø, Harper DA, Ryan PD. (2001). Past: Pale- obtained by instrumental measurements of dates had ontological statistics software package for education a significant correlation with the sensory evaluation of and data analysis. Palaeontologia Electronica 4(1): textural parameters. Among the eight sensory attributes 1-9 (Article 4). studied, four were well predicted with their respective Hossain MZ, Waly MI, Singh V, Sequeira V, Rahman instrumental measurements. These attributes were MS. (2014). Chemical composition of date-pits and hardness, resilience, chewiness, and elasticity. The sig- its potential for developing value-added product-a nificant correlations between the sensory attributes and review. Polish Journal of Food and Nutrition Sciences the instrumental measurements showed great promise 64(4): 215-226. for developing quality control during the selection of Ismail B, Haffar I, Baalbaki R, Henry J. (2008). Physi- dates for commercial processing. co-chemical characteristics and sensory quality of two date varieties under commercial and industrial Acknowledgement storage conditions. LWT-Food Science and Technol- Authors acknowledge the Sultan Qaboos University for ogy 41(5): 896-904. PhD Scholarship to Vandita Singh. She appreciates the Jia C, Kim YS, Huang W, Huang G. (2008). Sensory support of the A’Sharqiyah University to complete this and instrumental assessment of chinese moon cake: manuscript from her thesis. The Authors declare no Influences of almond flour, maltitol syrup, fat, and conflict of interest. gums. Food Research International 41(9): 930-936. Joyner HS. (2018). Explaining food texture through rhe- References ology. Current Opinion in Food Science 21: 7-14. Aguirre M, Owens C, Miller R, Alvarado C. (2018). De- Kim EJ, Corrigan V, Hedderley D, Motoi L, Wilson A, scriptive sensory and instrumental texture profile Morgenstern M. (2009). Predicting the sensory tex- analysis of woody breast in marinated chicken. Poul- ture of cereal snack bars using instrumental measure- try Science 97(4): 1456-1461. ments. Journal of Texture Studies 40(4): 457-481. Al-Hinai KZ, Guizani N, Singh V, Rahman MS, Al-Sub- Kurotobi T, Hoshino T, Kazami Y, Hayakawa F, Hagu- hi L. (2013). Instrumental texture profile analysis of ra Y. (2018). Relationship between sensory analysis date-tamarind fruit leather with different types of hy- for texture and instrument measurements in model drocolloids. Food Science and Technology Research strawberry jam. Journal of Texture Studies 49(4): 359- 19(4): 531-538. 369. Barbieri S, Bendini A, Balestra F, Palagano R, Rocculi P, Li P, Wu G, Yang D, Zhang H, Qi X, Jin Q, Wang X. Toschi TG. (2018). Sensory and instrumental study (2020). Applying sensory and instrumental tech- of taralli, a typical italian bakery product. European niques to evaluate the texture of french fries from Food Research and Technology 244(1): 73-82. fast food restaurant. Journal of Texture Studies 51(3): 521-531. Battaglia C, Vilella GF, Bernardo AP, Gomes CL, Biase AG, Albertini TZ, Pflanzer SB. (2020). Comparison Mestres C, Briffaz A, Valentin D. (2019). Rice cooking of methods for measuring shear force and sarcomere and sensory quality. Rice. Elsevier. p.385-426. length and their relationship with sensorial tender- Meullenet JF, Lyon B, Carpenter JA, Lyon C. (1998). Re- ness of longissimus muscle in beef. Journal of Texture lationship between sensory and instrumental texture Studies 51(2): 252-262. profile attributes. Journal of Sensory Studies 13(1): Chandrasekaran M, Bahkali AH. (2013). Valorization 77-93. of date palm (phoenix dactylifera) fruit processing Nishinari K, Fang Y, Rosenthal A. (2019). Human oral by-products and wastes using bioprocess technology processing and texture profile analysis parameters: - review. Saudi Journal of Biological Sciences 20(2): Bridging the gap between the sensory evaluation and 105-120. the instrumental measurements. Journal of Texture Studies 50(5): 369-380.

60 SQU Journal of Agricultural and Marine Sciences, 2021, Volume 26, Issue 1 Singh, Shafiur, Guizani, Hakikulla Shah

Paula AM, Conti-Silva AC. (2014). Texture profile and Singh V, Guizani N, Al-Zakwani I, Al-Shamsi Q, Al-Ala- correlation between sensory and instrumental analy- wi A, Rahman M. 2015. Sensory texture of date fruits ses on extruded snacks. Journal of Food Engineering as a function of physicochemical properties and its 121: 9-14. use in date classification. Acta Alimentaria 44(1): Philipp C, Buckow R, Silcock P, Oey I. (2017). Instru- 119-125. mental and sensory properties of pea protein-for- Singh V, Guizani N, Essa M, Hakkim F, Rahman M. tified extruded rice snacks. Food Research Interna- (2012). Comparative analysis of total phenolics, fla- tional 102: 658-665. vonoid content and antioxidant profile of different Prakash M, Ravi R, Sathish H, Shyamala J, Shwetha M, date varieties (phoenix dactylifera l.) from sultanate Rangarao G. (2005). Sensory and instrumental tex- of oman. International Food Research Journal 19(3): ture measurement of thermally processed rice. Jour- 1063-1070. nal of Sensory Studies 20(5): 410-420. Taniwaki M, Sakurai N, Kato H. (2010). Texture mea- Rahman MS. (2009). Food properties: An overview. surement of potato chips using a novel analysis tech- Food Properties Handbook. CRC Press, Boca Raton, nique for acoustic vibration measurements. Food Re- FL. p. 16-23. search International 43(3): 814-818. Rahman MS. (2019). Traditional foods, sensory excite- Tao K, Yu W, Prakash S, Gilbert RG. (2020). Investigat- ments and pleasure. Traditional foods. Springer, New ing cooked rice textural properties by instrumental Yourk. p.273-292. measurements. Food Science and Human Wellness 9(2): 130-135. Rahman MS, Afaf K-E, Al-Attabi Z, Khan MS, Al Bu- lushi IM, Guizani N, Al-Habsi N. (2020). Selected Yu L, Turner M, Fitzgerald M, Stokes J, Witt T. (2017). sensor technology innovation in food quality and Review of the effects of different processing technol- safety. Science and technology innovation for a sus- ogies on cooked and convenience rice quality. Trends tainable economy. Springer, New York. p.59-88. in Food Science & Technology 59: 124-138. Singh V, Guizani N, Al-Alawi A, Claereboudt M, Rah- man MS. (2013). Instrumental texture profile analysis (TPA) of date fruits as a function of its physico-chemical properties. Industrial Crops and Products 50: 866-873.

Technical notes 61 Journal of Agricultural and Marine Sciences 2021, 26(1): 62–65 DOI: 10.24200/jams.vol26iss1pp62-65 Reveived 09 Sep 2020 Accepted 30 Nov 2020 Perspective Papers Effect of COVID-19 pandemic situation on the teaching of Graduation Projects and Internship type courses in undergraduate degree programs

Hemanatha P. W. Jayasuriya

أتثري حالة جائحة COVID-19 على تدريس مشاريع التخرج والتدريب امليداين يف برامج درجة البكالوريوس هيمانثا جاايسرياي

Abstract. The COVID-19 pandemic has negatively impacted all aspects of social life all over the world. It has also significantly affected the global education system from primary to tertiary levels. The effect on college education has likely to be substantial, as some specializations and academic activities have undergone severe setbacks by virtue of the need for the presence of dynamic, face to face student-teacher interactions to provide effective teaching delivery. This article pinpoints the evident setbacks from a quality assurance perspective, when considering selected components such as graduation projects, internships, laboratory and field work in certain degree programs. Keywords: COVID-19 pandemic, accreditation criteria, student learning outcomes, teaching delivery, graduation projects, internships

املســتخلص:أثرت جائحــة COVID-19 ســلباعلــى ًمجيــع جوانــب ومناحــي احليــاة االجتماعيــة يف مجيــع أحنــاء العــامل لــكل مــن البلــدان املتقدمــة والناميــة. كمــا أثــرت بشــكل كبــ علــى رينظــام التعليــم العاملــي مــن املرحلــة االبتدائيــة إىل املراحــل اجلامعيــة املتقدمــة. ولقــد كان التأثــري علــى مرحلــة التعليــم

اجلامعــي كبــ ا، ًريحيــث تعرضــت بعــض التخصصــات واألنشــطة األكادمييــة النتكاســات شــديدة بســبب احلاجــة إىل وجــود تفاعــل ديناميكــي وجهــاً لوجــه بــن الطــاب واحملاضريــن لتقــدمي تعليــم فعــال. حتــدد هــذه املقالــة النكســات الواضحــة مــن منظــور ضمــان اجلــودة مــن خــال اختيــار عناصــر للتقييــم مثــل مشــاريع التخــرج، والتدريــب امليــداين، والعمــل املخــ ي ربوامليــداين لعــدد مــن الربامــج أالكادمييــة. الكلمات املفتاحية: جائحة كوفيد-19، معايري االعتماد، خمرجات التعليم، طرق التدريس، مشاريع التخرج، التدريب العملي.

Perspectives emerged with online or distance teaching, however there are significant components such as; laboratory he COVID-19 pandemic has been denominat- practical’s, field work, field visits, projects, internships, ed as a public health crisis by the World Health and co-op type training coming under secondary and Organization (WHO) (WHO COVID-19, 2019). tertiary education that must not be compromised in TWithout discrimination, the virus has affected all coun- order to avoid any detriment to the students education. tries, developed and developing, including the span of The impediments due to the pandemic on tertiary edu- different societal levels. The pandemic has had a mon- cation may have an adverse effect as some of the online umental effect on the livelihood of people resulting in teaching and evaluation techniques utilized are grossly all gatherings being prohibited including the sectors violating the stipulated accreditation requirements in pertaining to education. The effect on education at all some college degree programs. levels has become one of the main concerns for academ- Identification of effective teaching methods in light ic institutions at primary, secondary and tertiary levels. of the COVID-19 pandemic is in continuous discussion One positive is various new technological developments amongst academics and educational institutions. The Hemantha P. W. Jayasuriya ( ) [email protected], Department of uses of e-learning techniques and computer-based in- Soils, Water and Agricultural Engineering, College of Agricultural and novations have largely answered some of the prevailing Marine Sciences, Sultan Qaboos University, Muscat, Oman areas of concern (Hetsevich, 2017; Parashchenko, 2020; Rosel, 2020). However, there are obstacles to be met for Hemantha P. W. Jayasuriya

courses with a specific nature that relies on active inter- surance requirements. Considering the importance of actions to meet particular teaching objectives such as not delaying the graduation of students, alternative on- courses with projects, fieldwork and, laboratory compo- line teaching and assessment methods have been iden- nents. In addition to that, the execution of internships tified by academic institutions and relevant authorities widely used in engineering, science and technology ed- around the globe. ucation at college level that needs hands-on experiences Having stated the possibilities of online teaching with were notably affected. new technologies, there are components of teaching that This article has taken a few examples to provide cannot be compromised and compensated by this online an overview of the challenges encountered due to the approach, illustrating the harsh effects of the COVID-19 pandemic in the teaching delivery of capstone cours- pandemic. Two such areas in undergraduate programs es, graduation projects and the execution of internship are Internships and Graduation Projects (shown in Fig- programs embedded in the study plan of the Agricul- ure 1); both are considered essential components of any tural Engineering degree program at Sultan Qaboos undergraduate curriculum. When it comes to the intern- University, Oman. The course outlines of these courses ship component, undergraduate students are supposed are adhered to the ABET (Accreditation Board for Engi- to undergo training with career-guidance professionals neering and Technology) accreditation criteria and the at relevant work establishments where they are given teaching objectives, continuous and final assessments status as trainee employees. Due to the pandemic, some are aligned with ABET specified Student Learning Out- institutions and programs have initiated online intern- comes (SLOs). ship programs; however, the success of these approaches During the course teaching delivery in capstone-grad- will be program-specific or depend on the nature of the uation projects, students are expected to engage with degree program, but would not be properly replicated. real-world, meaningful projects that are low-cost and Similarly, for the Graduation Project component, use appropriate-technology. As a part of creative think- undergraduate students individually, or in small groups ing process with direct interactions by the instructor, should engage in realistic projects relevant to their field the project topic identification is given as a prominent of study under the supervision of an academic or pro- brain-storming task and follows an area of national or fessional in the same specialization. These projects en- regional importance that is feasible for a small group of able them to accomplish some of the SLOs stipulated by students to carry out. In capstone project type courses, the degree program objectives under the accreditation students are required to select a project, design and de- process. Such SLOs include the; application of scien- velop, prototype fabrication, performance evaluation, tific or engineering principles, a creative thinking ap- and provide reports and oral presentations defending proach, the use of appropriate strategies and standard the outcomes of their project for assessment. Conse- procedures for solving realistic problems, engagement quently, evaluations are based on the accomplishment of in life-long learning, team work and brain-storming SLOs; such as the application of engineering principles, for acquiring solutions, and finally the successful in- use of a creative thinking approach, and adoption of ap- terpretation and presentation of the project outcomes. propriate strategies and standard procedures for solving The above-mentioned learning outcomes are specified design problems, engagement in life-long learning, team as requirements by ABET (ABET Criterion 3, 2019). work for interpretation and presentation of project out- Project Based Learning (PBL) method (PBL, 2020) comes are also of significance (ABET Criterion 3, 2019). is currently one of the recommended approaches that Before this pandemic situation, student teaching eval- facilitates online delivery of teaching and instructions uations were on the high end (above 3.5/4.0) and with for successful completion of specific project type tasks highly positive comments under open-ended questions, such as graduation projects to some extent. However, such as “satisfaction on achievements of making some- the projects of development and validation nature that thing workable solving a identified problem”, “success fall under engineering and technology areas will not due to teamwork and continuous instructor interac- be completely successful without having the necessary tion” etc. Some of the prototypes developed by student student-teacher interactions and hands-on activities. groups won competitions (TRC/OCC Awards, 2019; Al Watan, 2019), and were submitted for patents and Conclusion commercialization programs, and some extended for postgraduate research studies (Al-Hinai and Jayasuriya, As the pandemic seems to continue for the present and 2020; Al-Hinai et al., 2019; Jayasuriya et al., 2018). Before until uncertain future, there are major challenges for the COVID-19, the teaching delivery of these courses could academics in these specific areas to find alternative active be considered as high-impact teaching practice making teaching delivery methods to overcome possible learn- it a captivating learning approach for students. However, ing deficiencies that may impact their graduates during under the influence of this pandemic, teaching delivery the pandemic period. As a short-term alternative, de- of these courses has become a serious challenge along grees can be awarded pending completion of such com- with the need to satisfy the accreditation and quality as- ponents once the cessation of the pandemic situation.

Perspective Papers 63 Effect of COVID-19 pandemic situation on the teaching of Graduation Projects and Internship type courses in undergraduate degree programs

Figure 1. Examples of graduation projects (a and b) and internship activities (c) with essential hands-on practice needed for creative thinking and skills development in undergraduate studies

Unfortunately, an enormous level of uncertainty lies TRC/OCC Awards. (2019). Sawsan Al-Khanbashi won ahead due to uncontrollable fluctuations in COVID-19 the best project idea in the first phase of the Inno- infections with multiple waves appearing in some coun- vation Room Award for a project “designing a dried tries. It is time for academic institutions and potential lime pulp extraction machine” The Research Coun- employers around the globe to create internationally cil and Oman Chamber of Commerce awards 2019, Oman TV, September 16, 2019. acceptable guidelines on accreditation and quality assurance standards for the graduates completing their Al Watan. (2019). “Anfal Al Hamdani wins a project degrees during the COVID-19 global pandemic. More- related to a dried lime extraction machine at Qa- over, there is a dire need for innovating and developing tar foundation competition”, Al Watan Newspaper, Oman, November 11, 2019. new teaching delivery methods to mitigate abovemen- tioned deficiencies as long-term solutions, not only for Jayasuriya HPW, Al-Hinai, A, Al-Adawi S, Al-Mah- COVID-19, but also for any future pandemic situation. douri, A. (2018). Comparison of ergonomic performance evaluation in mechanized and traditional date stripping processes, ASABE Library paper No. References 1800790, ASABE Annual International Meeting ABET Criterion 3. (2019). https://www.abet.org/accred- 2018 (doi:10.13031/aim.201800790.. itation/accreditation-criteria/criteria-for-accredit- Hetsevich I. (2017). Advantages and disadvantages of ing-engineering-programs-2019-2020/#GC3 E-learning technologies for students. https://www. Al-Hinai A, Jayasuriya H, Al-Adawi S, Al-Mahdouri A. joomlalms.com/blog/guest-posts/elearning-advan- (2019). Ergonomic Performance Evaluation of Date tages-disadvantages.html (accessed 20 October, Stripping Process, Advances in Intelligent Systems 2020) and Computing, SpringerBook Series (AISC), vol- Parashchenko T. (2020). The undeniable benefits of ume 789, p. 74-84. E-learning in the education industry. https://husky- Al-Hinai A, Jayasuriya, H. (2020). Development of a jam.com/blog/what-are-the-benefits-of-e-learning/ stripper machine for Al-Mabsili dates and evaluation (accessed 18 October, 2020) of human interactions and performances, Advances PBL (2020). PBL works. https://www.pblworks.org/ in Intelligent Systems and Computing, Springer Book what-is-pbl (accessed 15 October, 2020) Series (AISC), Volume 1018, p. 737-742.

64 SQU Journal of Agricultural and Marine Sciences, 2021, Volume 26, Issue 1 Hemantha P. W. Jayasuriya

Rosel, C. D. (2020). Advantage of e-learning. Blog CAE. https://www.cae.net/advantage-of-elearning/ (accessed 15 October,2020) WHO COVID-19. (2019). Coronavirus disease (Covid-19) https://www.who.int/emergencies/diseases/novel-coronavirus-2019 (accessed 10 October, 2020).

Perspective Papers 65 Guidelines for authors

Guidelines for Authors

The Journal of Agricultural and Marine Sciences (JAMS) is an manuscript. open access international peer-reviewed journal that publishes If suitable for the journal, the editors will choose 2-3 reviewers original fundamental and applied research articles in a wide among researchers working in a similar field and listed in the jour- variety of disciplines of the agricultural and marine sciences. nal database. The selection of reviewers is based on several factors: The journal provides a forum for specialists and practitioners expertise, reputation, specific recommendations of the author or of and brings together quality papers dealing with agricultural a reviewer, and our own previous experience of a reviewer’s char- economics, natural resource economics, animal and veterinary acteristics. The editors will request a minimum of two independent sciences, bio-resources, biotechnologies, soil sciences, water reviews but can if necessary request additional evaluations, par- management, agricultural engineering, fisheries, marine sci- ticularly if 2 reviewers have severely contradictory opinions on a ences, food science, human nutrition, plant production, plant particular submission. protection, rural environment, coastal zone management and Following the reviews, the section editor will place the manuscript oceanography. All issues of the Journal of Agricultural and Ma- among 4 categories: rine Sciences are freely available online and do not carry any publication charges. 1. Accepted with minor modifications; the paper requires mostly Types of manuscript published editorial and typographic modifications). 2. Accepted conditionally to a revision of the papers following the Manuscripts submitted for publication in the Journal of Agricul- recommendations and specific comments or concerns of the re- tural and Marine Sciences must be based on original work and viewers (the reviewers found incomplete or unclear statements have not been published, accepted for publication or submitted for that needs to be revised; some of the results may need to be rein- publication elsewhere. The journal accepts the following types of terpreted or some figures redrawn; part of the discussion may need manuscripts: some additional work). The acceptance remains conditional until 1. Editorials (by invitation only) the editor is satisfied with the revision. 2. Reviews (Review papers not exceeding 6000 words or 14 print- 3. Acceptable but only after after a second round of reviews (the pa- ed pages including figures, with prior approval from the Editor in per cannot be accepted without a thorough revision of its structure Chief) or significant changes in its presentation. The author will receive all 3. Research Articles (Original research not exceeding 6000 words or comments from the first set of reviewers and requested to resubmit 14 printed pages including figures) the paper with the suggested modifications and amendments. 4. Notes (Original research papers not exceeding 3000 words or 6 4. Not acceptable. There are major flaws in the experimental -de printed pages including figures and bibliography) sign, sampling protocol or analytical protocol that preclude a sound analysis or if the reviewers found significant overlap with 5. Perspectives (short papers, not exceeding 3000 words or 6 pages, published results. that present an opinion or a novel interpretation of existing ideas) The editor will then inform the corresponding author of his edi- 6. Snapshots (single page paper focusing on a high quality illustra- torial decision and convey the comments and suggestions of the tion, and a very short —5 references— bibliography). reviewers to which the author has to respond normally within 2-4 weeks. Authors may contact the editor through the journal email Submission system if they require an extension. New manuscripts should be submitted online through the jour- After reception of a revised manuscript, it may be subjected to nal management system (https://journals.squ.edu.om/index.php/ an additional round of review, particularly if the manuscript was jams). Note that authors who are not yet registered with the journal originally placed in the “acceptable” category. The final decision of management system, need to first create an identity by register- acceptance or rejection lies with the Editor in Chief in coordination ing on the journal website(https://journals.squ.edu.om/index.php/ with the whole editorial board and the Sultan Qaboos University jams). Once registered, corresponding authors can login with their Academic Publication Board. chosen username and password. All communications between authors, editors and reviewers are To facilitate the preparation of manuscripts that correspond to the made using the Editorial Management System at: http://journals. Journal structure, the Editorial boards has prepared a series of tem- sfu.ca/squjams/index.php/squjams/index plates in Microsoft Word and Apple Pages. They can be download- Authorship ed from the main submission page : https://journals.squ.edu.om/ index.php/jams/about/submissions#authorGuidelines. Authorship must be based on all of the following criteria: (1) sub- We also provide export style files for Endnotes (.ens) and Zotero, stantial contribution to the conception and design of the study, Papers and other bibliographic software that use the .csl citation data acquisition, analysis and interpretation of the data; (2) draft- format files. These as well as a pdf version of this documents can ing the article or revising it critically and; (3) final approval of the be downloaded from both the Journal Submission page (https:// version of the manuscript to be published. Contributors who do journals.squ.edu.om/index.php/jams/about/submissions#au- not meet all 3 of these criteria should be listed in the acknowledge- thorGuidelines). ments section of the manuscript. The corresponding author is responsible for taking all necessary coordinating actions for revising Reviewing policy the manuscript, receiving authorization from other authors, etc. The Journal of Agricultural and Marine Sciences uses a blind re- Scientific misconduct view process in which the peer reviewers’ names are not disclosed to the authors, although the reviewer can make himself known According to standard practices in scientific journals, SQU Journal should he choose to do so. Before submitting the papers for re- of Agricultural and Marine Sciences follows the recommendations view the editors will evaluate the manuscript suitability for the of Council of Science Editors (www.councilscienceeditors.org) and journal (language, readership, format), insure the completeness of define misconduct as: the submission and make an initial “plagiarism” assessment of the 1. Data Corruption: falsifying data, inventing data, ignoring part

66 SQU Journal of Agricultural and Marine Sciences, 2015, Volume 19, Issue 1 of the data purposefully, or any form of omission, suppression or of the paper should be based on a high quality photographic evi- distortion of data. dence of rare organisms, new records, unusual observation, severe 2. Plagiarism: using published or unpublished texts, ideas or pathology, etc. These submissions, because of their short nature, do thoughts of another writer without acknowledgements and pre- not have abstracts. The illustration needs to have an accompanying senting them as one’s own. Plagiarism includes duplicate publica- legend. tions or submissions in the same or in another language. The journal will follow COPE guidelines to identify and manage cases of Language and translations plagiarism or text recycling. The journal publishes papers in the English language with trans- 3. Authorship misconduct: Exclusion of involved researchers, or lation into Arabic of the title, authors and abstract of all papers. inclusion of researchers who have not contributed significantly to Arabic speaking authors are invited to provide the editorial board the work (see section on authors), or publication without the con- with an Arabic translation of the title and abstract. For non-Arabic sent of all authors. speakers, the board will provide a translation. 4. Ethical misconducts: Failure to follow legal requirements in British English spelling, usage, and punctuation are used through- acquiring the necessary permission to sample, collect, export or out the journal. Papers accepted for publication will be edited by import specimens, collect data, use chemicals or obtain ethical the Journal editorial office for conciseness, clarity, grammar, spell- permits in the country of the author’s institution. ing and style. Should the editing be extensive and possibly alter the SQU Journal of Agricultural and Marine Sciences takes all forms intended meaning of the author(s), queries will be sent by email to of misconduct very seriously. It follows the Committee for Pub- the corresponding author requesting clarifications. lication Ethics (COPE) recommendations and guidelines (publi- Style cationethics.org/resources/guidelines). Final decisions regarding The Journal follows the overall evolution of the scientific language. scientific misconducts are taken by the Editor in Chief. When preparing manuscripts please avoid jargon and long or complex sentences but aim at clear, concise and simple grammatical Types of articles structures. The editorial board encourages the use of the active The journal accepts several types of articles and recommends the voice when it is appropriate. following submission length and subsections Abstract Editorials (by invitation only) The Editorial board strongly suggests the use of a “structured ab- Editorials should not exceed 2000 words and a maximum of 25 ref- stract” not exceeding 300 words. These abstracts, although com- erences. posed of a single paragraph, include 5 sections that summarize Reviews the content of the paper: introduction, objectives, methodology, results and conclusion. Each section is introduced by a heading fol- Reviews should not exceed 6000 words and 14 pages and approxi- lowed by a colon and a series of sentences. mately 100 References. Authors who would like to submit a review are requested to send to the Editor in chief ([email protected]. Preparation of the manuscript om) a one page letter of intention outlining the focus and scope of the projected review before submitting their review online. The All papers will be typeset by the editorial team of the journal at abstract of a review paper, although structured, does not have to publication time. Therefore, the editorial board requests the au- follow the “5 section template”. thors to follow a clear and simple format for their manuscript Research Articles (original research not exceeding 6000 thereby facilitating the reviewing and editorial process. Templates for Microsoft Word™ and Apple Pages™ are provided to assist au- words) thors in preparing their manuscripts. Research papers should not exceed 6000 words or 14 pages and 50 The editorial board recommends the use of a classic typeface references. They should be divided into the following 6 sections: (Times, Helvetica, Garamond, Myriad-Pro, …) with 12 point size Abstract, Introduction, Materials and Methods, Results, Discus- and at least 14-16 points leading (line spacing) for the text of the sion and References. Additional sections such as Acknowledge- manuscript with minimum formatting as most of layout and ty- ments, Conclusions or Recommendations can also be included. pographical formats will be applied at the typesetting stage. The Although merging results and discussion is possible, it is not a manuscript page size should be A4 or US Letter and the editorial structure encouraged by the editorial board. board recommends that a margin of at least 3 cm be included on Notes (original research not exceeding 6 printed pages) all sides of the paper. Notes are short original research articles. They should not exceed To facilitate the reviewing process, the text of the submission 3000 words and 30 references or 6 printed pages. They should have should have line numbers in the left hand margin restarting at 1 on the same overall structure as Research Articles including a struc- each page and a page number in the footer of the document. Use tured abstract. standard typographic conventions for the text presentation: italic typeface for species names (not underline), bold face for vectors, Perspectives (short papers, not exceeding 3000 words) true superscript and subscripts when necessary. Emphasis is better Perspective papers are short papers that present an opinion or nov- marked through italic rather than bold face. el interpretation of existing ideas or data. They may also present an Typography historical perspective on one of the themes of the journal. These manuscripts should follow a structure and a logical sequence of The journal uses standard typographic convention throughout. The sections related to the content and purpose of the paper. editorial board recommends that you follow these in the preparation of the manuscript. Snapshots Italic should be used throughout for the Latin name of species A Snapshot manuscript is a single page paper focusing on a high (please do not use underlined text). Emphasis can be placed on quality illustration. The paper itself should not exceed one page and some elements of text using bold face. lists only a maximum of 3 references. Snapshot papers illustrate the : Avoid non-standard abbreviations whenever pos- common say “One picture is worth a thousand words”. The topic Abbreviations sible, particularly in headings and subheading. If, for the sake of

Guide for Authors 67 Guidelines for authors

conciseness, the author wishes to use abbreviations, define each manuscript on separate pages and the legend/caption of each table abbreviation when they first appear in each section of the man- should be placed on the same page and above the table. uscript. Standard abbreviation such as RNA, DNA, ATP, ADP, Equations and numbers EDTA… do not need to be defined as most readers will be familiar with them. Others such as PAH (Polycyclic Aromatic Hydrocar- Equations should be placed on separate lines and numbered se- bon) or ICP (Inductively Coupled Plasma) should be defined as quentially at the end of the line. They should be typeset using an most reader may not be familiar with their meaning. equation editor. If this is not possible scan or photograph a clear handwritten version of the equation which will be typeset by the Units: Always use the International System of Units (SI) for all editorial team. units. For large or small units use the standard multiplier prefix for the units (k for 1000, M for 1000000, m for 1/1000 and µ for 10- The Journal uses the modern scientific number styles recommend- 6). Prefer whenever possible negative exponents to slash: kg·m-2 ed by the Council of Science Editors. This styles uses digit numbers rather than kg/m2. To separate units, use either a mid-line point (· (1, 2,4.5, 7, etc.) for all numeric representations, even single digit =ASCII code 183 – Unicode U+00B7) or a non-breaking space. The ones. The main exceptions are when a digit starts a sentence, or abbreviated symbols (k, kg, s, P, W, etc. ) should be used whenever when the single digit number is part of an idiomatic expression possible and combined with Arabic numbers (5 kg, 2 m2, 5.2 MP, such as in “one or both”, a “zero-tolerance policy”, a “one-to-one 6.78 MW·h). The only exception is when a number is grammatical- interview”, “one has to agree that”… ly placed at the beginning of the sentence. A non-breaking space (Unicode U+00A0 ) should be used between the number and its References units to insure that they stay together in the final document. The SI SQU Journal of Agricultural and Marine Sciences uses a variation unit of time is s (second), h stands for hora, min for minuta, d for of the Author-Date style of references developed by the Council dies (day) and a for annum (year). of Science Editors (CSE). Output style files for Endnote and CSL When necessary, non-SI units can be added between parenthesis (Citation Style Language) are available for download on the Journal to allow comparison with older literature or traditional systems of Submission Management Web Page: measurements. This includes usual units, such as surface of farm- https://journals.squ.edu.om/index.php/jams/about/submis- ing units (faddan, acres, ares, hectares), or traditional depth units sions#authorGuidelines (fathoms, brasses, Ba’,…) or distance (nautical miles, miles) or other non SI units (gallons, inch, foot, bushels, etc. ). In-text citations Illustrations Citation in the text should be either Name (date) or (Name date) depending on whether the authors of the cited paper have a gram- Illustrations should be numbered consecutively and submitted as matical function in the sentence or not. Note the absence of punc- individual files, not embedded in the article file. To insure com- tuation between the author and the date. When several references patibility, the journal accepts the following file format: JPEG, TIFF, are grouped in a single inline citation, the different references are PNG, PDF, EPS and SVG. Although the journal is normally pub- separated by a semi-colon (; ). lished in black and white, color illustrations can be used when color Jones et al. (2007) listed 4 main types of … is clearly necessary to convey the intended message. Although the According to Jones et al. (2007), the main reason for…. authors can suggest the inclusion of color figures in the paper, the The prevalence of coral parasites was considerably lower than final decision to include them or not is left to the editorial board. that reported in Tanzanian coral reefs (Mwaniki, 1996). The editorial team will strive to provide the best possible graph- ic output from the material submitted by the authors and may in Different papers that share the same in-text citation format (same some cases decide to redraw some figures to improve readability. authors and same year of publication) are identified by a small let- They may also request better quality photographs or color figures if ter (a, b, c) following the date of publication. When used in a single necessary. Typically black and white line figures should have a res- citation, the author’s name is not repeated. olution of at least 600 dpi (at the final printed size) and color figures The ticks collected on camels were not different from that found or photographs 300 dpi (at the final printed size) but should not on goats (Bobade, 2004a) or sheep (Bobade, 2004b). exceed 10 MB. For line graphics, vector based file formats (SVG, There were no differences in the species of ticks collected on PDF, EPS) are preferred as they are resolution independent. different farm animals (Bobade, 2004a; 2004b)… Each illustration should have at the bottom of the page a brief iden- The family name of the first author is always used. For publications tifier such as the name of the first author, the word Figure and the with 2 authors, the 2 family names with the conjunction “and” are sequential number of the figure. (Al-Oufi, Figure 7 for instance). used followed by the year of publication. For more than 2 authors, The full captions of all figures should be presented in numerical the abbreviation et al. (Latin et alii – and others) is used to replace order on a separate page at the end of the text manuscript. all but the first author’s name. Jones et al. (2007) listed 4 main types of soft coral communi- In the figure use Helvetica as the standard typeface for all text (axis, ties… legend, axis legend, equations, labels, etc.) and ensure that all text Al-Barwani and Jones (2005) found 3 genetically distinct popu- remain legible even after size reduction for final printing. Figures lations of mussels… will be printed either as a single column (7 cm wide) or double The Omani clownfish has a distribution restricted to 400 km column (14 cm) figure along the Arabian Sea coast of Oman (Simpson et al. 2014). Macro-photographs, micro-photograhs, SEM photographs, an- End of text references atomical drawings, morphological illustrations, should have an appropriately labeled scale bar. Avoid multiplication factors (x100, The bibliographic information for all cited references in the articles x10000) as these will change with the rescaling of the figure when are listed at the end of the papers under the heading “References”. printed. The list of references is sorted first following the alphabetical order Tables of the authors and if necessary, by the date of publication. Please follow the examples shown below, including punctuation. The Tables should be presented in a clear manner and designed to fit on Journal names follow a “Title case” capitalization—all words are the width of a page. Exceptionally wide tables may be typeset, side- capitalized except for articles (a, an, the); for prepositions (against, ways, along the height of a printed page. All unnecessary decimals of, in, to), for conjunctions (and, for, not, or)—and should NOT be should be removed. Tables should be included at the end of the abbreviated. Titles of articles, books, on the other hand follow a

68 SQU Journal of Agricultural and Marine Sciences, 2015, Volume 19, Issue 1 sentence case capitalization (i.e. words are capitalized according to Submission checklist the grammar of the language of publication): the first word, the first word that follow a colon or a semi colon, names of geographic lo- 1. The current submission has not been previously published nor is cations, or proper nouns, etc. For articles published in non-English it currently submitted to another journal for consideration. languages, provide the original title if the language uses roman 2. The submission text files are in Microsoft Office (.doc, .docx), characters or a translation of the title for other languages (Arabic OpenOffice (.odt), RTF (rtf) or Apple Pages (.pages) document file for instance) and add the name of language between 2 periods at format. the end of the reference. 3. The text of the document uses a 12-point standard font with a 14- For online references, follow the overall same standard as for print 16 point leading (space between lines) on A4 or US-Letter format publication, but include a date of access and if possible a DOI num- pages with page numbers and line numbers. Manuscript conforms ber. to the journal recommended styles, length and number of sections. Volume and issues, if available, follow directly the Title of the 4. The Abstract of the paper follows the structured format de- Journal with the issue number between parenthesis. Page num- scribed in the guide for authors and includes a single paragraph bers follow a colon and are separated by an hyphen. For books, the (<300 words) with 5 inline headings (Introduction, Objectives, total page number is used with the abbreviation “pp.” whereas for Method, Results and Conclusions) and keywords for the manu- sections of books, the abbreviation is “p.” followed by the range of script are provided. pages of the section (p. 25-44). All references ends with a period. 5. Photography (or photographic plates) are submitted in the jpeg Journal reference with 1 author (.jpg) file format at 300 dots per inch (dpi) with 80% compression Adams NA. (2001). UV radiation evokes negative phototaxis quality or better. Line drawings and other figures should be prefer- and covering behavior in the sea urchin Strongylocentrotus ably submitted as vector graphics such as pdf, eps or svg files. Al- droebachiensis. Marine Ecology Progress Series 213: 87-95. ternatively, high resolution (600dpi) image format are acceptable Journal reference with 2 authors (PNG, TIFF, GIF). Zhou M, Huntley ME. (1997). Population dynamics theory of 6. All tables including (legend, description and footnotes) and all plankton based on biomass spectra. Marine Ecology Prog- figure captions are part of the submission main text file. ress Series 159: 61-73. 7. The text adheres to the stylistic and bibliographic requirements Journal reference with more than 2 authors outlined in this document which can also be found in About the Schlacher TA, Thompson l, Price S. (2007). Vehicles versus Journal on the Journal web site. conservation of invertebrates on sandy beaches: Mortalities 8. The manuscript has been “spell-checked” and “gram- inflicted by off-road vehicles on ghost crabs. Marine Ecology mar-checked”. 28: 354-367. Whole book Supplementary material Parsons TR, Maita Y, Lalli CM. (1984). A manual of chemical and JAMS accepts electronic supplementary material to support pub- biological methods for seawater analysis. New York: Pergam- lished manuscripts. These may include high-resolution images, on Press. 173 pp. sound-tracks, datasets and will be published online along with the Book chapter from an edited book electronic version of the published paper. Data should be provided Brooks HA, Probert TH. (1984). Let’s ask GMDH what effect the in one of the supported format (pdf, doc, docx, otd, rtf, pages, jpeg, environment has on fisheries. In: Farlow SJ, editor. Self-orga- png, tiff, svg…) for printable documents and standard formats for nizing methods in modeling. Gmdh type algorithms. New non-printable documents (AIFF, MP4, MP3, etc.). York and Basel: Marcel Dekker, Inc. p.169-178. Report Copyrights Stransky C. (2001). Preliminary results of a shape analysis of The content of the journal is licenced under the Creative Common redfish otoliths: Comparison of areas and species. Northwest (CC BY ND) licensing schemes the details of which can be found at Atlantic Fisheries Organization. NAFO SCR No. 4382. https://creativecommons.org/licenses/by-nd/4.0/legalcode. Thesis Al-Masroori HS. (2002). Trap ghost fishing problem in the area Contact details between Muscat and Barka (Sultanate of Oman); an evaluation study [MSc.]. [Muscat]: Sultan Qaboos University. 112 pp. The Editor-in-Chief Article not in English JAMS Editorial Office Samimi NS. (2004). Soft-corals and gorgonians of the Iranian College of Agricultural and Marine Sciences shore of the Straight of Hormuz. Iranian Journal of Oceanog- Sultan Qaboos University raphy 7(2): 45-49. Farsi. P.O. box 34, Postal Code 123 Conference proceedings Al-Khod, Muscat Campbell AC. (1988). The echinoderm fauna of Dhofar (southern Sultanate of Oman Oman) excluding holothuroids. In: Burke RD, Mladenov PV, Lambert P, editors. Proceedings of the Sixth International Tel: (968) 2141 1257 Echinoderm Conference; 23-28 August 1987; Victoria, Cana- da: Balkema. p. 369-378. Submission at https://journals.squ.edu.om/index.php/jams Email: [email protected] Alternate email: [email protected]

Guide for Authors 69 احملتوايت ورقة ابحاث

التقييم املكاين والزماين للغطاء النبايت يف والية السويق وحتليله ابستخدام صور األقمار الصناعية 1 كاذية العويف ومالك الوردي وبيماانغود تشودري ومشتاق أمحد وغازي الرواس وايسني املال أتثري ظروف التخزين على جودة الطماطم بعد احلصاد: دراسة حالة على مستوى السوق 13 مي الدايري، ابنكاج ابثري، عادل احملذوري ِ ِ ِ ِ إلتهاب الضرع َحتت َّالس ِرير َّي يف اإلبل يف عمان: د َراسة إْرتيَاديَّة 21 حممد ندمي عاصي، وليد املرزوقي، ايمسني الطاهر، الغالية الطويب، سارة الرئيسي، هيثم علي، الشفيع إبراهيم الشفيع، يوجني هاربر جونسون الكفائة و التحكم البيولوجي يف مفاعل حيوي غشائي و عملية احلمأة املنشطة التقليدية ملعاجلة مياه الصرف الصحي البلدية 27 بثينة الوهييب، عبدهللا املأمون، حماد سعيد ابعوين، أمحد سنا متوسط التباين يف مستوى سطح البحر على طول الساحل الشمايل لبحر عمان واستجابته للرايح املومسية ومؤشر تذبذب مشال األطلسي من مقياس املد واجلزر 37 س. امسعیل حسن زاده و ف. حسینی ابالم التأثري الوقائي ملستخلص أوراق النبااتت الربية العمانية ) السيداف و احلميضة( ضد اإلجهاد التأكسدي الناجم عن تسرطن القولون يف حيواانت التجارب 47 مصطفى وايل، حممد اخلصييب، جنيب قيزاين

مالحظة فنية

التقييم امليكروبيلوجي لألمساك اجملففة حمليًا يف عمان: مالحظة فنية 53 عائشة الساعدي، عبد الرحيم اإلمساعيلي، حممد الرزيقي، إمساعيل البلوشي االرتباط بني السمات املقيمة حسيا و ابألجهزة لفاكهة شجرة النخيل )التمر( ).Phoenix dactylifera L(: مالحظة فنية 57 فانديتا سينغ، حممد شفيور الرمحن، جنيب غيزاين، حقيق هللا شاه

وجهة نـظـر

أتثري حالة جائحة COVID-19 على تدريس مشاريع التخرج والتدريب امليداين يف برامج درجة البكالوريوس 62 هيمانثا جاايسرياي www.squ.edu.om/agr/JAMS جملة العلوم الزراعية والبحرية

مواقع أخذ عينات الرتبة واملياه.

العناوين اجمللد 26، العدد 1، 2021 •التقييم املكاين والزماين للغطاء النبايت يف والية السويق وحتليله ابستخدام صور األقمار الصناعية •أتثري ظروف التخزين على جودة الطماطم بعد احلصاد: دراسة حالة على مستوى السوق ِ ِ ِ •إلتهاب الضرع َحتت َّالس ِرير َّي يف اإلبل يف عمان: د َراسة إِْرتيَاديَّة •الكفائة و التحكم البيولوجي يف مفاعل حيوي غشائي و عملية احلمأة املنشطة التقليدية ملعاجلة مياه الصرف الصحي البلدية •متوسط التباين يف مستوى سطح البحر على طول الساحل الشمايل لبحر عمان واستجابته للرايح املومسية ومؤشر تذبذب مشال األطلسي من مقياس املد واجلزر •التأثري الوقائي ملستخلص أوراق النبااتت الربية العمانية ) السيداف و احلميضة( ضد اإلجهاد التأكسدي الناجم عن تسرطن القولون يف حيواانت التجارب •التقييم امليكروبيلوجي لألمساك اجملففة حمليا ًيف عمان: مالحظة فنية •االرتباط بني السمات املقيمة حسيا و ابألجهزة لفاكهة شجرة النخيل )التمر( ).Phoenix dactylifera L(: مالحظة فنية •أتثري حالة جائحة COVID-19 على تدريس مشاريع التخرج والتدريب امليداين يف برامج درجة البكالوريوس