Effect of Different salt Concentrations on the Quality and Chemical Composition of the Fish Hydrocynus spp

Abstract

This piece of work was done in an attempt to evaluate the issue of the traditional fish salting practice in the Sudan. Fassiekh was selected as one of the widely consumed salted fish product, of great preference among Sudanese consumers.The study was directed towards the study of the proximate chemical composition to compare the effect of the different salt concentrations on the nutritive value of fish, mineral content and heavy metal concentration. In both fresh fish and fassiekh. Beside this, some other parameters including: the microbiological analysis of fresh fish and fassiekh, and the effect of salting on the final product weight were studied. One kind of fish species preferable by Sudanese consumers in fasseikh making was selected for this study namely hydrocynus spp (kass). Samples were taken from Elmawrada fish market in Omdurman, and subjected to three salt concentration levels (15%, 20%and 25%) by weight to achieve the goals of the study. Fresh fish were carefully handled throughout the preparation process; they were eviscerated and cleaned up and divided in to two groups then three sup groups to be treated with different salt concentration. After the fermentation process sample were taken to do the proximate, minerals, microbiological analysis after 10 days. The loss in weight after 10 and 20 day. Proximate analysis targeted the determination of moisture%, protein%, ash%, fat and pH. Minerals contents were determined by wet samples. The analysis of results obtained show that the weight loss in the salting process has significant difference between fresh and salted fish on different salt concentration; in the salt concentration 15% the loss in weight was 158g after 10 th day and 210g after 20 th day. in 20% salt the loss was 179 in 10 th day and 247g on the 20 th day and in 25% the loss was 221g in the 10 th and 262g in 20 th . The proximate composition of the fresh samples was 70.9%, 24.2%, 3.8%, 1.2% and VII 7.05 for moisture, protein, fat, ash and pH respectively. The proximate composition of fassiekh (moisture, protein, fat, ash and pH) for 15% salt was 60.3%, 21.7%, 3.4%, 10.5% and 6.6 respectively. And for 20% salt was 56.7%, 19.2%, 3.2%, 12.9% and 6.0 respectively. And for 25% salt was 52.2%, 17.6%, 1.9%, 14.1%, and 5.8 respectively.As for the proximate composition of fassiekh it is clearly observed that all the studied parameters are significantly different in fresh treated samples. Variations appeared to be due to the interaction of the salting treatment. It was also observed that, the minerals contents of the fresh fish (Potassium, Sodium, Iodine, Phosphorous, Chlorine, Zink, Copper and Iron) were significantly different in different salt concentration while Calcium and Magnesium and the heavy metal (Arsenic, Cadmium and lead) concentration were not significant. The microbiological analysis result showed significant decrease in total bacterial count in all concentrations.