Preservation of Farmed Carp (Naini) Fish by Salting Followed by Drying

cess Pro ing d & o o T F e c f h o Basnet et al., J Food Process Technol 2013, 4:3

o DOI: 10.4172/2157-7110.1000212

r Journal of Food

y o

J Processing & Technology ISSN: 2157-7110

Research Article Open Access Preservation of Farmed Carp (Naini) Fish by Salting Followed by Drying and it’s Quality Evaluation Dharma Raj Basnet1*, Rewati Raman Bhattarai1, Achyut Mishra2 and Basanta Kumar Rai2 1Central Campus of Technology, Hattisar, Dharan, Nepal 2Scientific Officer, Nepal Agricultural Research Council (NARC), Kathmandu, Nepal

Abstract Salting and drying of fish was studied for preservation ofNaini fish. Quality evaluation was done to study the shelf life. Naini fish was procured from Regional Agricultural Rearch station, Tarahara, Sunsari, Nepal. Three different treatment temperature (RT, 4°C and 10°C), different brine of salt concentration (4%, 8%, 12% and 16%) and four different brine treatment times (6, 12, 18, 24 hours) were optimized in this study. Sensorically, at RT (26°C) in brine of 12% salt concentration for 12 hours, at 4°C in brine of 16% salt concentration for 24 hours and at 10°C in brine of 16% salt concentration for 18 hours were optimized for Naini fish preservation. Peroxide values of these three best samples were evaluated for quality (shelf life) upto three months at 1.5 months interval. At the end of present study,

peroxide value of all three samples were within acceptable limit (PV<8 meq O2/kg). Peroxide value of sample treated

at10°C in brine 16% salt concentration for 18 hours was found to be significantly least (5.46 meq O2/kg). Thus for preservation and longer shelf life, treatment of Naini fish at 10°C in brine of 16% salt concentration for 18 hours and drying thereafter to about 8% moisture is the best condition.

Keywords: Naini fish; Salting and drying; Chemical composition; They inhabit altitudes ranging from a few hundred metres above sea Sensory evaluation; Shelf life level to as high as 4000 metres. Three indigenous major carps (rohu- Labeo rohita, catla-Catla catla and Naini-Cirrhinus mrigala) are Introduction already included in the country’s aquaculture production systems [2]. Fish is highly recommended diet particularly to the small children Preservation of fish in developing countries like Nepal is generally as well as to pregnant and breast feeding women to meet their protein done by traditional method i.e., salting or drying; salting and requirement for better growth. Fish forms and excellent for human drying or by salting, smoking and drying. The combination effect of being because of many reasons like, easily digestible rich protein and salting, smoking and drying is more effective to extend the self- life. less fatty with cholesterol free meat [1]. Fishes commodity is relatively a new investment in Nepal therefore this field is relatively in infant Preservation for a long term is generally done by freezing or canning and under developing stage. Major part is pond fishes, where about but in developing country like Nepal is not possible due to expensive 6735 hectare of village ponds, 12500 hectare wetland, 500 hectare operations. lakes, 395000 hectare rivers and 1500 hectare reservoirs of water bodies The principle aim of preservation is to delay, reduce or inhibit the have been exploited for fish production in Nepal but significantly in spoilage. In case of fatty fish, the preservation may also aim at reducing Terai region. There are around 186 fish species in Nepal, among them or inhibiting oxidation and other undesirable changes in the fish oils, some catfish have high economical/ecosystem values as their taste, which are highly unsaturated and capable of going rancid at various aboundances, fishing characters and growing habit [2]. stages of processing [5]. Carp is one of the oldest domesticated species of fish for food. According to the FAO statistics of 2004 [3], production of farmed Materials and Methods common carp was about 13% (3,387,918 tones) of the total global The study was conducted at Central Campus of Technology, freshwater aquaculture production. Asia is the main producing region Hattisar, Dharan during 2011-2012. of the species with the majority of production consumed domestically. Carp are considered as delicacy in many countries throughout the Fish world. They are tolerant to wide range of temperature, oxygen levels and salinities. Fresh Naini fish weighing total of 6 kg, each around 30-40 g was purchased from Regional Agricultural Research Station, Tarahara, Naini (Cirrhinus mrigala), a carp, is one of the three major carp species cultivated widely in Southeast Asian countries. This species has long been important in polyculture with other native species, mainly *Corresponding author: Dharma Raj Basnet, Central Campus of Technology, in India. In addition, Naini has become an important component in Hattisar, Dharan, Nepal, Tel: 9779842128728; E-mail: [email protected] the fish culture systems of Nepal, Bangladesh, Pakistan, Myanmar, Received November 19, 2012; Accepted December 28, 2012; Published January the Lao People’s Democratic Republic and Thailand. Naini has also 10, 2013 been introduced into Sri Lanka, Vietnam, China, Mauritius, Japan, Citation: Basnet DR, Bhattarai RR, Mishra A, Rai BK (2013) Preservation of Malaysia, Philippines and the former USSR [4]. Naini is fast growing Farmed Carp (Naini) Fish by Salting Followed by Drying and it’s Quality Evaluation. fish & therefore preferred for pisciculture. When cultured artificially J Food Process Technol 4: 212. doi:10.4172/2157-7110.1000212 Naini can grow to a great size. Rich in protein content as food [3]. Copyright: © 2013 Basnet DR, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits There are 186 species of fish in Nepal. It has been reported that a unrestricted use, distribution, and reproduction in any medium, provided the total of 186 fish species are found in various water bodies in Nepal. original author and source are credited.

J Food Process Technol ISSN:2157-7110 JFPT, an open access journal Volume 4 • Issue 3 • 1000212 Citation: Basnet DR, Bhattarai RR, Mishra A, Rai BK (2013) Preservation of Farmed Carp (Naini) Fish by Salting Followed by Drying and it’s Quality Evaluation. J Food Process Technol 4: 212. doi:10.4172/2157-7110.1000212

Page 2 of 9 sunsari, Nepal. It was brought by keeping in a clean polythene bag within 20 minutes in the laboratory of Central Campus of Technology. Fish Naini

Methodology Preliminary Processing (Gut, scales, fins were removed)

Fish were dressed using knife and then gutted, fins were removed Washing and washed with tap water. Brine solutions were made of 4%, 8%, 12% Brining in salt concentration and 16% salt concentration and fish were dipped in this solutions which are kept at room temperature (at 26°C ), at 4°C and at 10°C. These 12% 4% At RT (268%°C) , at 4°C and at 10°C 16% samples were drawn at 6 hours, 12 hours, 18 hours and 24 hours from this different temperature and were brought to dry in cabinet dryer. Samples were ta ken after 6 hrs, 12 hrs, 18 hrs and 24hrs

Drying

The brined fishes were simply introduced into cabinet dryer of Central Campus of Technology. Preliminary drying was done at 45- • Preliminary drying, at 50°C for 1 hour 50°C for about 1 hour to prevent from case hardening and then thermal • Thermal treatment, at 80°C for 1 hour treatment was done at 80-85°C for 1 hour to denature protein and final Cooling • Final drying, at 60°C until moisture becomes about drying was done at 60°C to the final moisture content of the fish about 8%. 8%. The product obtained after drying were cooled and packed in clean

PP (30µm) by heat sealing machine. The flow chart for the preparation Packaging in PP of salted-dried fish is shown in figure 1. Labeling Chemical analysis Storage

Fresh fish was analyzed for moisture, crude protein, crude fat, ash, Figure 1: Flowchart for preparation of salted- dried fish. carbohydrate and peroxide value was determined for the final product. Moisture content was determined according to [6]. Crude protein content in the fresh fish was determined according to AOAC and Constituents Value (%) Subba [6,7]; crude fat in the fresh fish as per AOAC and Subba [6,7]; Moisture content 78.3(0.31) ash content as per Subba [6]; carbohydrate content by difference and Crude protein 17.4(0.41) peroxide value for the final product as per Subba [6]. Crude fat 2.5(0.21) Ash 1.6(0.13) Sensory evaluation Carbohydrate 0 The final products were evaluated for texture, flavor, color, taste The values in the parenthesis give standard deviation of three replicates. and overall acceptance on 9 point hedonic rating test by a selected Table 1: The chemical composition of fresh fish flesh on wet basis. panel of 6 judges. Concentration (%) Color Flavor Texture Taste OA Statistical data analysis 4 4.33a 4.33a 5.17a 5a 5.16a The data were subjected to statistical analysis and the scores 8 5b 5.5b 6b 5.8b 5.83b given by the panelist were analysed by Two-way Analysis of Variance 12 6.67c 5.66b 6.5b 6bc 6.5c (ANOVA) at 5% level of significance to determine whether the samples 16 7.33d 6.5c 7.5c 6.33c 7.33d were significantly different from each other and also to determine LSD (P<0.05) 0.608 0.476 0.605 0.498 0.53 which one is superior between them. The values are the mean of six panelist score. The values having same superscript in a column did not differ significantly at 5% level of significance. Results and Discussion Table 2a: Summary of the statistical test showing the difference between the treatments and within the variates for optimization of salt concentration in brine at Chemical composition of fresh fish flesh room temperature (26°C) for 6 hours. The fresh fish flesh taken from the fish (Naini) of Tarahara Farm Concentration (%) Color Flavor Texture Taste OA was analysed in the laboratory for its chemical composition. The 4 5.33a 5.17a 5.33a 5.33a 5.66a scientific name of the fish is Cirrhinus mrigala. The table 1 shows the 8 6b 6b 6.33b 5.50a 7b chemical composition of fresh fish flesh. 12 7.83c 7.33c 8.50c 7.17b 8c Sensory analysis of salted dried fish 16 6.66d 6.83c 7d 6.33c 7b LSD (P<0.05) 0.53 0.686 0.498 0.622 0.317 A nine point hedonic rating of the salted dried fish was carried out The values are the mean of six panelist score. The values having same superscript with 6 panelists. The sensory scores for optimization of concentration in a column did not differ significantly at 5% level of significance. and time are given in table 2a-2e, table 3a-3e and table 4a-4e. Table 2b: Summary of the statistical test showing the difference between the treatments and within the variates for optimization of salt concentration in brine at Sensory analysis of salted dried fish treated at RT (room room temperature (26°C) for 12 hours. temperature) for optimization of salt concentration in brine and time: The mean sensory scores for optimization of salt concentration for sample dipped in brine of 8 and 12% salt concentration in 6 hr but in brine and time are given in table 2a-2e. The graphical representation significantly different (p<0.05) for 4 and 16% salt concentration in 6 hr. for optimization of salt concentration at room temperature (26°C) for No significant difference was found for taste in 6 hr for brine of 12% and 6 hours is shown in figure 2a. The statistical analysis shows that there 16% salt concentration whereas brine of 4% and 16% salt concentration was no significant difference (p>0.05) between flavor, texture and taste were significantly different. The color and overall acceptance (OA)

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Concentration (%) Color Flavor Texture Taste OA The sample treated in brine of 16% concentration for 6 hr had higher 4 5.33a 5.16a 5.5a 5.5a 5.5a score for color. More preference to this sample by panelists may be 8 6a 6.16b 6.17b 6.5b 6b due to the satisfactory glossy skin. Protein dissolves in brine of suitable 12 7.66c 7c 7.67c 7c 7.33b concentration to give a sticky solution, during the dripped period this 16 6.5d 6.33b 6.83d 6d 6.66c dries on the outer surface and produces the familiar glossy skin [8]. LSD (P<0.05) 0.481 0.467 0.658 0.389 0.576 The sample dipped in brine of 16% salt concentration was accepted in The values are the mean of six panelist score. The values having same superscript terms of texture and flavor by panelists may be due to the sufficient salt in a column did not differ significantly at 5% level of significance. penetration into the sample. Higher the salt concentration, the greater Table 2c: Summary of the statistical test showing the difference between the the replacement of water [9]. treatments and within the variates for optimization of salt concentration in brine at room temperature (26°C) for 18 hours. The graphical representation for optimization of salt concentration in brine at room temperature (26°C) for 12 hours is shown in figure Concentration (%) Color Flavor Texture Taste OA 2b. The statistical analysis shows that there was significant difference 4 5.5a 5.66a 5.66a 5.67a 5.6a (p<0.05) between color, flavor, texture and overall acceptance for 8 6.16b 6.33b 6.16a 6b 6.16b sample dipped in brine of 4%, 8%, 12% and 16% salt concentrations 12 7.5c 7.16c 7.5b 7c 7.5c 16 6.66d 7c 6.83c 6.5d 6.33b Concentration (%) Color Flavor Texture Taste OA LSD (P<0.05) 0.498 0.425 0.53 0.463 0.565 4 5.66a 5.67a 5.83a 5.5a 5.83a The values are the mean of six panelist score. The values having same superscript 8 5.83a 6a 6.5b 6.17b 6.33b in a column did not differ significantly at 5% level of significance. 12 6.5b 6.66b 7c 6.67b 6.83c Summary of the statistical test showing the difference between the Table 2d: 16 7.83c 7.83c 7.82d 7.33c 7.83d treatments and within the variates for optimization of salt concentration in brine at room temperature (26°C) for 24 hours. LSD (P<0.05) 0.53 0.481 0.383 0.608 0.463 The values are the mean of six panelist score. The values having same superscript Time (hr) Color Flavor Texture Taste OA in a column did not differ significantly at 5% level of significance. 6 6.67a 5.66a 6.5a 6a 6.5a Table 3c: Summary of the statistical test showing the difference between the b b b b b 12 8.16 7.5 8.33 7.16 8.16 treatments and within the variates for optimization of salt concentration in brine at 18 7.66bc 7c 7.67c 7b 7.33c 4°C for 18 hours. 24 7.5c 7.16bc 7.5c 7b 7.5c LSD (P<0.05) 0.594 0.43 0.686 0.40 0.594 Concentration (%) Color Flavor Texture Taste OA 4 6a 5.67a 5.83a 5.66a 5.66a The values are the mean of six panelist score. The values having same superscript b b b b b in a column did not differ significantly at 5% level of significance. 8 6.33 6.33 6.33 6.16 6.33 12 7.33c 7c 7.33c 6.83c 7.16c Table 2e: Summary of the statistical test showing the difference between the d d d d d treatments and within the variates for optimization of time at room temperature 16 8.33 7.66 8.5 7.5 8.33 (26°C) for brine of 12% salt concentration. LSD (P<0.05) 0.317 0.518 0.389 0.481 0.383 The values are the mean of six panelist score. The values having same superscript Concentration (%) Color Flavor Texture Taste OA in a column did not differ significantly at 5% level of significance. 4 4.5a 5.33a 4.66a 5.33a 5a b a b a b Table 3d: Summary of the statistical test showing the difference between the 8 5.16 5.83 5.66 5.5 5.5 treatments and within the variates for optimization of salt concentration in brine at 12 6.66c 6.16a 6b 6.33b 6.16c 4°C for 24 hours. 16 6.83c 6.83b 6.83c 6.16b 6.83d LSD (P<0.05) 0.425 0.514 0.36 0.467 0.425 Time (hrs) Color Flavor Texture Taste OA 6 6.83a 6.83a 6.83a 6.17a 6.83a The values are the mean of six panelist score. The values having same superscript b b b a b in a column did not differ significantly at 5% level of significance. 12 7.66 7.5 7.66 5.67 7.67 18 7.83b 7.83b 7.82b 7.33b 7.83b Table 3a: Summary of the statistical test showing the difference between the 24 8.33c 7.66b 8.5c 7.5b 8.33c treatments and within the variates for optimization of salt concentration in brine at 4°C for 6 hours. LSD (P<0.05) 0.389 0.425 0.481 0.608 0.449 The values are the mean of six panelist score. The values having same superscript Concentration (%) Color Flavor Texture Taste OA in a column did not differ significantly at 5% level of significance. a a a a a 4 5.5 5.5 5.66 5.8 5.66 Table 3e: Summary of the statistical test showing the difference between the 8 5.83a 6.16b 6.33b 6a 6.16a treatments and within the variates for optimization of time at 4°C for brine of 16% 12 6.66b 6.5b 7c 7.16b 7b salt concentration. 16 7.66c 7.5c 7.66d 5.66a 7.66c Concentration (%) Color Flavor Texture Taste OA LSD (P<0.05) 0.343 0.55 0.565 0.565 0.514 4 4.67a 5.16a 4.83a 5.16a 5a The values are the mean of six panelist score. The values having same superscript 8 5.5b 5.66b 5.66b 5.5a 5.66b in a column did not differ significantly at 5% level of significance. 12 6.5c 6b 6b 6.33b 6.33c Table 3b: Summary of the statistical test showing the difference between the 16 6.83c 6.33b 7c 6.5b 7d treatments and within the variates for optimization of salt concentration in brine at 4°C for 12 hours. LSD (P<0.05) 0.619 0.481 0.481 0.481 0.41 The values are the mean of six panelist score. The values having same superscript scores for all concentrations were significantly different in 6 hr, hence, in a column did not differ significantly at 5% level of significance. significantly higher scores were awarded for sample treated with brine Table 4a: Summary of the statistical test showing the difference between the of 16% salt concentration in 6 hr at RT. treatments and within the variates for optimization of salt concentration in brine at 10°C for 6 hours.

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Concentration (%) Color Flavor Texture Taste OA in brine at room temperature (26°C) for 18 hours is shown in figure 2c. 4 5.66a 5.67a 5.83a 5.67a 5.83a The statistical analysis shows that there was no significant difference 8 6a 6.33b 6.33b 6a 6a (p>0.05) between flavor for sample treated with brine of 8% and 16% 12 6.83b 6.66b 7c 6.83b 7b salt concentration and OA for 4% and 8% salt concentration but 16 7.83c 7.33c 7.83d 7b 8c significantly different (p<0.05) for 12% and 16% salt concentration LSD (P<0.05) 0.343 0.534 0.449 0.619 0.251 in 18 hr. Significant difference was found for color and texture in all The values are the mean of six panelist score. The values having same superscript the concentration. Significantly highest score was awarded for sample in a column did not differ significantly at 5% level of significance. treated in brine of 12% salt concentration for all the sensory parameters. Table 4b: Summary of the statistical test showing the difference between the treatments and within the variates for optimization of salt concentration in brine at The sample treated in brine of 12% concentration for 18 hr had 10°C for 12 hours. higher score for color. More preference to this sample by panelists may be due to the satisfactory glossy skin. Protein dissolves in brine Concentration (%) Color Flavor Texture Taste OA of suitable concentration to give a sticky solution, during the dripped 4 5.83a 5.5a 5.83a 5.5a 5.83a period this dries on the outer surface and produces the familiar glossy 8 6.16b 6a 6.5b 6.16b 6.33b 12 7.16c 6.66b 7.33c 6.66b 7.16c skin [8]. The sample dipped in brine of 12% salt concentration was 16 8.16d 7.66c 8.5d 7.83c 8.16d accepted in terms of texture and flavor by panelists may be due to the LSD (P<0.05) 0.317 0.59 0.383 0.576 0.383 sufficient salt penetration into the sample. Optimum salt penetration The values are the mean of six panelist score. The values having same superscript in a column did not differ significantly at 5% level of significance. 9 Table 4c: Summary of the statistical test showing the difference between the 4% 8% 12% 16% treatments and within the variates for optimization of salt concentration in brine at 8 d c d 4°C for 18 hours. c c 7 b c c e b b bc b Concentration (%) Color Flavor Texture Taste OA o r b

s c b 6 a a 4 5.83a 5.5a 6a 5.66a 5.83a b a b b b a a 8 6.33 6.33 6.5 6.16 6.16 nsor y 5 a a s e

12 8.16c 7.5c 8.16c 7.5c 7.83b n 4 d b d a c 16 7.16 6.83 7.33 6.66 7 Me a LSD (P<0.05) 0.383 0.591 0.41 0.502 0.361 3 The values are the mean of six panelist score. The values having same superscript 2 in a column did not differ significantly at 5% level of significance. 1 Table 4d: Summary of the statistical test showing the difference between the treatments and within the variates for optimization of salt concentration in brine at 0 10°C for 24 hours. Color Flavor Texture Taste OA

Sensory parameters Time (hr) Color Flavor Texture Taste OA 6 6.83a 6.33a 7a 6.5a 7a (Similar alphabet above the bars indicates not significantly different (p>0.05). The error bars show the standard deviation.) 12 7.83b 7.33bc 7.83b 7a 8b 18 8.16b 7.66b 8.5b 8b 8.16b Figure 2a: Optimization of salt concentration in brine at room temperature (26°C) for 6 hours. 24 7.16a 6.83ac 7.33ab 6.67a 7a LSD (P<0.05) 0.485 0.561 0.58 0.605 0.251 The values are the mean of six panelist score. The values having same superscript in a column did not differ significantly at 5% level of significance. Figure 2a: Optimization of salt concentration in brine at room temperature (26°C) for 6 hours. 10 4% 8% 12% 16% Table 4e: Summary of the statistical test showing the difference between the c treatments and within the variates for optimization of time at 10°C for brine of 16% 9 c salt concentration. c c 8 b b c d b in 12 hr but no significantly different (p>0.05) in taste for 4% and 8 7 d b c b b % salt concentration in 12 hr. There was significantly different in taste e a a o r 6 a s c a a between the samples dipped in brine of 12% and 16% salt concentration. a Similarly significantly highest score was awarded for 12% for all sensory 5 nsor y parameters. s e n 4

The sample treated in brine of 12% concentration for 12 hr had Me a 3 higher score for color. More preference to this sample by panelists 2 may be due to the satisfactory glossy skin. Protein dissolves in brine of suitable concentration to give a sticky solution, during the dripped 1 period this dries on the outer surface and produces the familiar glossy 0 skin (Burgess et al., 1967). The sample dipped in brine of 12% salt Color Flavor Texture Taste OA concentration was accepted in terms of texture and flavor by panelists Sensory parameters may be due to the sufficient salt penetration into the sample. Figure 2b: Optimization of salt concentration in brine at room temperature (26°C) for 12 hours. The graphical representation for optimization of salt concentration

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Sensory analysis of salted dried fish treated at 4°C for 9 4% 8% 12% 16% optimization of salt concentration in brine and time c c 8 b c c The mean sensory scores for optimization of salt concentration d c 7 d b b b and time are given in table 3a-3e. The graphical representation for b b d a

e optimization of brine concentration at 4°C for 6 hours is shown in 6 a a o r a a a s c figure 3a. The statistical analysis shows that there was no significant

5 difference (p>0.05) between color and taste for sample treated with nsor y

s e 4 brine of 12% and 16% salt concentration in 6 hr. There was no significant n different between flavor for 4%, 8%, and12% but significantly different

Me a 3 for 16% salt concentration. No significant different was found between 2 textures for 8% and 12% salt concentration but significantly different 1 for 4% and 16% salt concentration. Significant difference was found between color for 4% and 8% but no significant difference in taste. 0 Color Flavor Texture Taste OA Significant difference was found between OA for all the concentration. Sensory parameters Significantly highest score was awarded for 16% salt concentration for Figure 2c: Optimization of salt concentration in brine at room temperature color, flavor, texture and OA. (26°C) for 18 hours. The sample treated in brine of 16% concentration for 6 hrhad higher score for color. More preference to this sample by panelists in fish product improves the texture and makes the final product may be due to the satisfactory glossy skin. Protein dissolves in brine appreciated by consumers [10]. of suitable concentration to give a sticky solution, during the dripped The graphical representation for optimization of salt concentration in brine at room temperature (26°C) for 24 hours is shown in figure 2d. 9 4% 8% 12% 16% The statistical analysis shows that there was no significant difference 8 c b c c c c (p>0.05) between flavor for sample treated with brine of 12% and 16% d c 7 d b b b b salt concentration but significantly different (p<0.05) for 4% and 8 a b % salt concentration in 24 hr. There was no significant difference in 6 a a a a a e texture for 4% and 8% salt concentration but significantly different for o r 5 s c

12% and 16% salt concentration. No significant difference was found 4 for OA in 8% and 16% salt concentration but significantly different for nsor y s e 3 4% and 12% salt concentration. Significant difference was found for n color and taste for all the concentration. Significantly highest score was Me a 2 awarded for 12% salt concentration for all the sensory parameters. 1 The sample treated in brine of 12% concentration for 24 hr had 0 higher score for color. More preference to this sample by panelists Color Flavor Texture Taste OA may be due to the satisfactory glossy skin. Protein dissolves in brine Sensory parameters of suitable concentration to give a sticky solution, during the dripped Figure 2d: Optimization of salt concentration in brine at room temperature period this dries on the outer surface and produces the familiar glossy (26°C) for 24 hours. skin [8]. The sample dipped in brine of 12% salt concentration was accepted in terms of texture and flavor by panelists may be due to the sufficient salt penetration into the sample. 10 6hr 12hr 18hr 24hr The graphical representation for optimization of time at room b 9 b b temperature (26°C) for brine of 12% salt concentration is shown in bc c 8 c b c b c c figure 3e. The statistical analysis showed that there was no significant c bc b b a a a difference (p>0.05) between texture for 18 and 24 hr; between flavor for 7 a

re a 18 and 24 hr, 12 and 24 hr; between color for 18 and 24 hr, 12 and 18 6 sc o

hr; between taste for 12, 18 and 24 hr and between OA for 18 and 24 hr r y 5 but significantly different (p<0.05) for others. Significant higher score s o

se n 4 was awarded for all the sensory parameters for 12 hrs. n

e a 3 M The sample treated in brine of 12% concentration for 12 hr had 2 higher score for color. More preference to this sample by panelists 1 may be due to the satisfactory glossy skin. Protein dissolves in brine 0 of suitable concentration to give a sticky solution, during the dripped Color Flavor Texture Taste OA period this dries on the outer surface and produces the familiar glossy Sensory parameters skin [8]. The sample dipped in brine of 12% salt concentration for 12 hr was accepted in terms of texture and flavor by panelists may be due to Figure 2e: Optimization of time at room temperature (26°C) for 12% brine the sufficient salt penetration into the sample. concentration.

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The sample treated in brine of 16% concentration for 24 hr had

8 4% 8% 12% 16% higher score for color. More preference to this sample by panelists c c b c d may be due to the satisfactory glossy skin. Protein dissolves in brine 7 b a b b c of suitable concentration to give a sticky solution, during the dripped a b 6 a a a b period this dries on the outer surface and produces the familiar glossy b a e a a skin [8]. The sample dipped in brine of 16% salt concentration for 24

o r 5 s c

4 nsor y

s e 3 n 10 4% 8% 12% 16%

Me a 9 2 c c d c 8 1 c b b b b 7 b b a a 0 re a a a a a a a Color Flavor Texture Taste OA sc o 6 ry Sensory parameters 5

sens o 4 Figure 3a: Optimization of salt concentration in brine at 4°C for 6 hours. ean 3 M 2 period this dries on the outer surface and produces the familiar glossy 1 skin [8]. The sample dipped in brine of 16% salt concentration for 6 hr 0 was accepted in terms of texture and flavor by panelists may be due to Color Flavor Texture Taste OA the sufficient salt penetration into the sample. The rate of salt uptake is Sensory parameters very important with regard to weight change, water holding capacity Figure 3b: Optimization of salt concentration in brine at 4°C for 12 hours. (WHC) and even the taste of the final product [11]. The graphical representation for optimization of salt concentration in brine at 4°C for 12 hours is shown in figure 3b. The statistical analysis 9 showed that there was no significant difference (p>0.05) between d d c 4% c 8% 12% 16% color, taste and OA for sample treated with brine of 4% and 8% salt 8 c c c concentration in 12 hr but significantly different (p<0.05) for 12% 7 b b b b b b and 16% salt concentration in 12 hr. There was no significant different a a a a a a between flavor for 8% and 12% salt concentration but significantly 6 a e different for 4% and 8%. Significant difference was found between o r 5 s c texture for all the concentration. Significantly highest score was 4 awarded for 16% salt concentration for color, flavor, texture and OA. nsor y s e 3 n The graphical representation for optimization of salt concentration Me a 2 in brine at 4°C for 18 hours is shown in figure 3c. The statistical analysis showed that there was no significant difference (p>0.05) between 1 color and flavor for sample treated with brine of 4% and 8% salt 0 concentration in 18 hr but significantly different (p<0.05) for 12% and Color Flavor Texture Taste OA 16% concentration. No significant difference was found for taste for Sensory parameters 8% and 12% salt concentration but significantly different for 4% and Figure 3c: Optimization of salt concentration in brine at 4°C for 18 hours. 16%. Significant different was found between texture and OA for all the concentration. Significantly highest score was awarded for 16% salt concentration in 18 hr. 10 4% 8% 12% 16% The graphical representation for optimization of salt concentration 9 d d d in brine at 4°C for 24 hours is shown in figure 3d. The statistical d d 8 c c c analysis showed that there was significant difference (p<0.05) between c c 7 e b b color, flavor, texture, and overall acceptance for all the concentration. a b b b o r a a a a

s c 6 The mean score awarded highest for 16% salt concentration for all the sensory parameters. 5 nsor y

s e 4 The graphical representation for optimization of time at 4°C for n 3 brine of 16% salt concentration is shown in Figure 3e. The statistical Me a analysis shows that there was no significant difference (p>0.05) was 2 found between color, texture and OA for 12 hr and 18 hr but significantly 1 different for others. There was no significant difference between taste 0 for 18 hr and 24 hr, 6 hr and 12 hr. No significantly different was found Color Flavor Texture Taste OA between flavor for 12 hr, 18 hr and 24 hr, but significant different for 6 Sensory parameters hr and others. The mean score awarded highest for color, texture, taste Figure 3d: Optimization of salt concentration in brine at 4°C for 24 hours. and OA for 24 hr.

Page 7 of 9 hr was accepted in terms of texture and flavor by panelists may be due to the sufficient salt penetration into the sample. The rate of salt uptake 9 c 4% 8% d 12% 16% c is very important with regard to weight change, water holding capacity 8 c b c b (WHC) and even the taste of the final product [11]. b b b 7 b b

re a a a Sensory analysis of salted dried fish treated at 10°C for 6 a a a a a sc o optimization of concentration and time r y 5 s o

se n 4

The mean sensory scores for optimization of salt concentration in n brine and time are given in table 4a-4e. The graphical representation for e a M 3 optimization of salt concentration in brine at 10°C for 6 hours is shown 2 in figure 4a. The statistical analysis shows that there was no significant difference (p>0.05) between color for sample treated with brine of 12% 1 and 16% salt concentration in 6 hr but significantly different (p<0.05) 0 for 4% and 8%. No significantly difference was found between flavor Color Flavor Texture Taste OA for 8%, 12% and 16% salt concentration but significantly different Sensory parameters for 4%. There was no significant different between taste for 4%and Figure 4b: Optimization of salt concentration in brine at 10°C for 12 hours. 8%, 12% and 16%; between texture for 8% and 12% but significantly different for others. There was significant difference between OA for all the concentration. The mean score awarded highest for 16% salt concentration for all the sensory parameters. 10 4% 8% d 12% 16% 9 d d The sample treated in brine of 16% salt concentration for 6hr c c 8 c c c b b

achieved good texture. High salt concentration causes small protein e 7 b b loss by the osmotic effect of the appropriate salt and gives appreciable o r b a b

s c a a a

a a texture [12]. The sample treated in brine of 12% concentration for 24 hr 6

nsor y 5 s e

n 4

10 Me a 3 6hrs 12hrs c18hrs 24hrs 9 c b c 2 b b b b b b b b b 8 b 1 a a a a 0

e 7 a a Color Flavor Texture Taste OA o r

s c 6 Figure 4c: Optimization of salt concentration in brine at 10°C for 18 hours. 5 nsor y

s e 4 n 3 Me a 10 2 4% 8% 12% 16% 9 d 1 d d c c 8 c c c 0 b b Color Flavor Texture Taste OA e 7 b b o r b a b

s c a a a Sensory parameters 6 a a Figure 3e: Optimization of time at 4°C for brine of 16% salt concentration nsor y 5 s e

n 4

Me a 3

8 2 c c 4% 8% 12% 16% d b 1 7 c b b c b b 0 6 b b b b Color Flavor Texture Taste OA a a a e a a o r 5 a Figure 4d: Optimization of salt concentration in brine at 10°C for 24 hours. s c

4 nsor y s e

n 3 had higher score for color. More preference to this sample by panelists

Me a may be due to the satisfactory glossy skin. Protein dissolves in brine 2 of suitable concentration to give a sticky solution, during the dripped 1 period this dries on the outer surface and produces the familiar glossy 0 skin [8]. Color Flavor Texture Taste OA Sensory parameters The graphical representation for optimization of salt concentration in brine at 10°C for 12 hours is shown in figure 4b. The statistical analysis Figure 4a: Optimization of salt concentration in brine at 10°C for 6 hours. shows that there was no significant difference (p>0.05) between color

Page 8 of 9

significant different between taste for 6 hr, 12 hr and 24 hr, between 10 6hrs 12hrs 18hrs 24hrs OA for 6 hr and 24 hr but significantly different for others. Significantly 9 c higher score was awarded for 18 hr for texture, taste and OA. b b b c b b b 8 bc ab a ac a a a a Shelf life study of product a a 7 a a

e The products were packed in packaging material polypropylene

o r 6

s c (PP). The shelf life analysis was carried out on the basis of chemical

5 analysis. Increase in peroxide value (PV) was evaluated to study shelf

nsor y 4 life. The graphical representation between peroxide value and storage s e

n 3 time (months) is shown in figure 5. Me a 2 The statistical analysis showed that there was significant difference 1 between samples for PV with storage days. In the beginning, the PV 0 of best three samples were found to be 2.89, 1.85 and 2.32 for samples Color Flavor Texture Taste OA treated RT, 4°C and 10°C respectively. Highest PV in zero months was Sensory parameters found for RT followed by 10°C and lowest for 4°C. This might be due Figure 4e: Optimization of time at 10°C for 16% brine concentration. to the lower temperature in case of 4°C. PV was found to be increased in linear fashion and the increase and OA for 4% and 8% salt concentration but significantly different in PV was significantly different between the samples. At the end of (p<0.05) for 12% and 16%. No significantly different between flavor storage days in present study, PV of sample treated at RT was 6.55, for 8% and 12% but significant different for 4% and 16%. There was at 4°C were 6.97 and at 10°C were 5.46. The values at the end of 3 no significant different between taste for 4% and 8%, 12% and16% months were within acceptable limit. According to Lawson [13], the but significantly different for others. Significantly highest score was product having peroxide value above 8meq/kg was not acceptable. awarded for 16% salt concentration in 12 hr. Thus we can concluded that the sample treated at 10°C in brine of 16% salt concentration dipped for 18 hours was best in terms of PV. The The graphical representation for optimization of brine lower PV in this case might be due to optimum storage temperature concentration at 10°C for 18 hours is shown in figure 4c. The statistical and brine treatment time which favored proper salt penetration that analysis showed that there was significant difference (p<0.05) between enhance shelf life. color, texture and OA for all the concentration. No significant difference was found between flavor for 4% and % salt concentration Conclusions but significant different was found for others. There was no significant Various conclusions were drawn from the present research. different between taste for 8% and 12% but significant different for Optimum conditions for preservation of Naini fish by salting and others. drying was found to be at 10°C treated in brine of 16% salt concentration The graphical representation for optimization of salt concentration for 18 hours. Alternative preservation conditions of Naini fish can be in brine at 10°C for 24 hours is shown in figure 4d. The statistical done at room temperature (26°C) in brine of 12% salt concentration analysis showed that there was significant difference (p<0.05) between for 12 hours and at 4°C in brine of 16% salt concentration for 24 hours color and texture for all the concentration. There was significant treatment. The peroxide value for best three samples packed in PP were different between taste and OA for 4% and 8% salt concentration but within acceptable limit (PV<8 meq O2/kg) in three months so quality significantly different for 12% and 16%. No significant difference was of fish at three months of storage was found to be acceptable. Hence found between flavor for 8% and 16% but significantly different for by these treatments shelf life were extended satisfactorily for three others. The mean score awarded highest for 12% salt concentration for months. As per PV, the best preservation technology is the treatment all the sensory parameters. at 10°C in brine of 16% salt concentration for 18 hours. Treatment at 10°C in brine of 16% salt concentration for 18 hours is most economic The sample dipped in brine of 12% salt concentration for 24 hr was way of preservation. accepted in terms of texture and flavor by panelists may be due to the sufficient salt penetration into the sample. The rate of salt uptakeis 9 very important with regard to weight change, water holding capacity RT, 12%, 12 hrs 4°C, 16%, 24 hrs 10°C, 16%, 18 hrs (WHC) and even the taste of the final product [11]. The sample treated 8 in brine of 12% concentration for 24 hr had higher score for color. More 7 preference to this sample by panelists may be due to the satisfactory 6 glossy skin. Protein dissolves in brine of suitable concentration to give 5 a sticky solution, during the dripped period this dries on the outer ) surface and produces the familiar glossy skin [8]. 4

meq/k g 3

The graphical representation for optimization of time at 10°C for V ( brine of 16% salt concentration is shown in figure 4e. The statistical P 2 analysis showed that there was no significant difference (p>0.05) 1 between color for 6 hr and 24 hr, 12 hr and 18 hr but significantly 0 different for others. There was no significant different between flavor 0 1.5 3 for 6 hr and 24 hr, 12 hr and 18 hr but significantly different for others. Storage time (months) No significant different was found between texture for 6 hr and 24 hr, Figure 5: Change in peroxide value of salted-dried fish packed in PP. 12 hr and 24 hr but significantly different for others. There was no

Page 9 of 9

References 7. AOAC (2005) Offical Method of Analysis. Association of Official Analytical Chemists, Washington, D.C, USA. 1. Jhingran VG (1991) Fish and fisheries of India. Hindustan publishing corporation, India. 8. Del Valle FR, Nickerson JTR (1967) Studies on Salting and Drying Fish. I. Equilibrium Considerations in Salting. J Food Sci 32: 173-179. 2. Thapa AB, Mehata SN, Shah PK (2008) Preliminary observation on domestication of Bhunna (Notopterus chitala) in pond condition at Tarahara. 9. Clucas IJ (1982) Fish Handling, Preservation and Processing in the Tropics, Fisheries Research Program RARS Tarahara, eastern Nepal. Part II. Tropical Development and Research Institute, UK.

3. FAO (2005). FISHSTAT Plus - Version 2.30 for 2003 statistics. 10. Andres A, Rodriguez-Barona S, Barat JM (2005) Analysis of some cod- desalting process variables. J Food Eng 70: 67-72. 4. Jhingran VG (1968) Synopsis of Biological Data on Rohu, Cirrhinus mrigala (Hamilton, 1822). FAO Fisheries Synopsis No. 32, FAO, Rome, Italy. 11. Poernomo A, Gyatmi, Fawzya YN, Ariyani F (1992) Salting and drying of Mackerel (Rastrelliger Kanagurta). ASEAN Food Journal 7: 141-146. 5. Afolabi OA, Arawomo OA, Oke LO (1984) Quality changes of Nigerian traditionally processed freshwater fish species. Int J Food Sci Tech 19: 333- 12. Rajbhansi KG (1996) Fisheries Development in Azad Jammu and Kashmir, 340. Handbook of Fish Culture.

6. Subba D (2010) Practical book of meat, poultry and fish technology. National 13. Lawson RM (1977) Socio-economic aspects of fisheries development. College of Food Science and Technology, Nepal. In:Proceedings of the conference on the Handling, Processing and Marketing of Tropical Fish, London, UK.

J Food Process Technol ISSN:2157-7110 JFPT, an open access journal Volume 4 • Issue 3 • 1000212