See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/322520649 EFFECTS OF SALTS ON PRESERVATION AND METABOLIC ACTIVITIES OF FISH AND MEAT MICROFLORA Article · January 2018 CITATIONS READS 0 63 3 authors: Oranusi Solomon Abah Kingsley Covenant University Ota Ogun State, Nigeria Covenant University Ota Ogun State, Nigeria 99 PUBLICATIONS 755 CITATIONS 4 PUBLICATIONS 1 CITATION SEE PROFILE SEE PROFILE Selina Anosike Covenant University Ota Ogun State, Nigeria 9 PUBLICATIONS 4 CITATIONS SEE PROFILE Some of the authors of this publication are also working on these related projects: Biogas and biofertilizer production from local biomasses View project Food safety; Public and environmental health View project All content following this page was uploaded by Oranusi Solomon on 16 January 2018. The user has requested enhancement of the downloaded file. EFFECTS OF SALTS ON PRESERVATION AND METABOLIC ACTIVITIES OF FISH AND MEAT MICROFLORA ORANUSI, 5.*, ABAH, K. A. AND ANOSIKE S.O. Department of Biological Sciences, Covenant University, Ota, Nigeria *Corresponding Author; Email: [email protected]; +2348065299155 Abstract Foods usually carry a mixed population ofmicroorganisms derived from both the natural microfloro of the food plant or animo/ and those introduced during handling, processing, and storage. Salt is a widely used additive and preservative, which, influences microorganisms in different concentrations. This study aims to determine the effect of salts on food preservation and metabolic activities of food microfloro. Two food samples (row fish and raw lean meat) were investigated. Sodium chloride (NaCI), Potassium chloride {KCI} and Calcium chloride {CoCI,) were grouped into varying concentrations of2, 2.5 and 4.5% respectively. The food samples were pulverized and salted according to these concentrations and on unsalted group served os the control. Storage was for fifteen days with samples analysis on days 0, 7 and 15. The first category of food sample was preserved under room temperature (28 ± 2 ·c), with the second and third under refrigeration (4 t 2 •C) and freezer (-18 t 2 •C) temperature respectively. Total protein and Lipid Peroxidation were assayed during the duration ofstor age. Organisms isolated from the samples were identified based on biochemical and cultural characteristics to include Staphylococcus oureus, Escherichia coli, and species of Pseudomonas, Klebsiella, Enterobocter, Aspergillus, Moulds, and Yeasts, with Bacillus spp mostly predominant. There was a decrease in microbial population along concentration and temperature gradient, the population, however, increosed.along the duration of storage. The toto/ protein decreased while lipid peroxidotion increased along the duration ofstorage. NaCI showed the highest efficiency in preservation, with KCI showing the least efficacy. Freezer temperature (-18 t 2 •C) and 4.5% salt concentrations were the most effective. Salts alone at concentrations acceptable in food cannot effectively contra/ on initio/ high load of natural and cantominont micraflora in row foods. Use of salts in synergy with ather preservatives/ methods like refrigeration will drastically reduce the activities offood microflora whilst enhancing the shelf-life ofthese foods. Keywords: Salts, food preservation, metabolic activities, lipid peroxidation, Microflora Introduction foods (Hall, 1997). Foods are rarely sterile Food is essential for the growth and because these organisms are present in the survival of man but becomes harmful air surrounding the food, water, and soil through the presence and action of from where the food plants and animals spoilage organisms and foodborne are harvested (ICMSF, 1996). Foods usually pathogens (ICMSF, 1996). Microorganisms carry a mixed populatio n of are known to be ubiquitous in nature; they microorganisms derived from both the can be found almost everywhere including natural microflora of the original plant or Journal of Industrial Research and Technology... 1/RT Vol. 6, No 1, 2017 90 Oranusl eta/: Effects of Salts on Preservation and Metabolic activities of Fish and Meat Microflora animal and those introduced during a/., (2010), salt is one of the most preferably harvest/slaughter and subsequent handling, used addit ives in food industries because of processing, and storage (Hall, 1997). Quality its low cost and varied properties. Its unique deterioration caused by th ese properties lie in the preservative and microorganisms may include a wide range of antimicrobial effect as a direct consequence types of spoilage that are not desirable of the capacity of sodium chloride to reduce commercially, because they limit shelf life or water activity values (Albarracin et a/., lead to quality complaints, but are safe from a 2010). Salt, which interacts with other public health point of view (ICMSF, 1996). The physicochemical parameters, have been presence or growth of infectious or toxigenic used as a preservative to inhibit the growth microorganisms (foodborne pathogens) of microorganisms while maintaining the represents the worst forms of quality shelf-life of food products (Andres et a/., deterioration because they threaten the 2005). Furthermo re, sodium ch loride health ofthe consumer (ICMSF, 1996). ICMSF, influences the activity of different proteases (1996) observed that despite the extensive and proteins such as (a-dependent scientific progress and technological protease; Cathepsin D and Cathepsin L developments achieved in recent years, food (Armenteros eta/., 2009). An increase in the safety problems continue to exist and may concentration of NaCI has been reported to actually increase in the future. Both intrinsic decrease protease activities and thus and extrinsic factors act synergistically to prevent the spoilage of meat (Armenteros et enhance or retard the growth of a/.,2009). microorganisms in food (Jay eta/., 2005).Salt is a widely used additive and preservative, Food-borne illnesses that occur from enhancing the flavour (Silva eta/., 2003) and consuming contaminated food with improving water adsorption in foods pathogenic bacteria have been of serious (Lawrence et a/., 2003). A high salt public health concern all over the world. concentration generates changes in cellular Food-borne illnesses associated with £. coli metabolism because of its osmotic effect, 0157:H7, Staphylococcus aureus, which, influences microorganisms in Salmonella enteritidis, Salmonella typhi and different concentrations. Bautista et a/ Listeria monocytogenes, is a major concern (2007) and Blesta eta/ (2008) reported that (Beuchat 1996, Hall, 1997 and Farber, 2000). the salts, NaCI, KCI and CaCI2 or their The result also informs of the need to wash combination drastically reduced water raw food products in potable water to activity in meat. Addition of salts leads to a reduce microflora before preservation sudden onset of plasmolysis, which causes because, in the presence of a high initial inhibition of nutrient uptake, DNA microbial load, preservation may virtually be replication and triggers an increase in the impossible. This work aims to determine ATP levels of cells, which further leads to the effects of salts on metabolic activities of inhibition of macromolecular biosynthesis food (meat and fish) microflora as (Csonka, 1989). Accord ing to Albarracin et purchased from the market Journal of Industrial Research and Technology... JIRT Vol. 6, No 1, 2017 91 Oranusi eta/: Effects of Salts on Preservation and Metabolic activities of Fish and Meat Microflora M aterials and M ethods Isolation and Enumeration of Bacteria and Sampling points Fungi Fish and Meat samples were collected from All inoculated plates were incubated at three different locations in a local market in 3rc for 24- 48 h to obtain viable bacterial Ota {Oja-Ota). Ota is located in Ogun state, counts, except, however, Saboraud Nigeria {7.9452"N, 4.7888°N). This market Dextrose agar plates that were incubated was chosen because it is the major one in at laboratory room temperature of 28 ± 2 town and many vendors patronize the oc for 72 h. Colonies were counted at the market for sales. Food grades of NaCI, KCI, expiration of incubation period using the colony counter (Gallenkamp, England). and CaCI were obtained from reputable 2 Counts were expressed as colony forming vendors. units per ml of sample homogenate (cfu/ml). Characteristic discrete colonies Collection of Samples on the different media were isolated and Major vendors of fresh fish and meat were purified by repeated sub-culturing on identified in the market. Samples were nutrient agar. Pure cultures were stored on randomly obtained from six vendors, three agar slants at 4°C for further (3) each for raw fish and meat samples. All characterization. the samples were collected in polyethylene bags as sold and transported in cold pack (2 Coliform Test ± 2"C) to the Microbiology Laboratory of The standard method of Speck, (1976) as Covenant University, Ota for analysis described by Oranusi et a/., (2013) was within 30 minutes-1hour after col lection. adopted. One gram of each sample was transferred to a sterile test tube containing Sample Preparat ion lactose broth and inverted Durham tubes. A sterile knife was used to remove fatty Incubation was for 24-48 h at 3rc before portions of the meat to obtain lean meat. tubes were checked for gas production. Twenty-five grams (25g) portions of the This was the presumptive test. A loop full of samples were minced in a laboratory inoculum