Studies on contamination and quality of fresh fish meats during storage

Abstract

The aimed of this study showed the possibility to evaluate the quality and find out the degree of contamination of local fresh fish meats, this fish its common name in Yemen is (Gahsh), and its scientific name is (Lethrinus elongatus). The samples taken from Taiz city markets [Republic of Yemen], and stored at room temperature, the microbiological, physical and chemical changes were followed by examination of samples during storage at zero time as (control samples) and every day. The results illustrate the microbial contamination increasing and the evaluation of the physical and chemical characteristics quality were decreased and deteriorated during storage. As well as isolation seventeen species of bacteria identified and classification to six groups of Bacillus spp obtained from prior samples. On other hand the population of Aerobic, Anaerobic, Spore formers, Yeast and Moulds Enterobacteriaceae, Coli form groups, Salmonella spp, Staphylococcus spp, Streptococcus spp, Clostridium spp, Bacillus spp, Enterococcus spp and Proteolysis bacteria, were increased by the following percentages: 68.56%, 43.2%, 26.75%, 28.82%, 49.59%, 16.66%, 15.00%, 30.53%, 24.24%,16.92%, 14.52%, 14.49%, and 50.50% respectively. The nutrition chemical characteristics i.e [Moisture, Protein and Fat content] were decreased as following percentages: 0.81 %, 0.54% and 0.63 % respectively, and the Carbohydrate content increasing as 43.97%. The chemical indicates for spoilage i.e [Total volatile nitrogen ,Tri methyl amine, Ammonia nitrogen, Thiobarabituric acid, Total energy value and Water holding capacity] increasing as following percentages: 147.87%, 114.74%, 82.55%, 62.57%, 1.43 % and 16.36% respectively. The pH value and Bound water decreased as 7.00% and 3.89% respectively, as compared with the control samples.