Effect of local processing methods (cooking, frying and smoking) on three fish species from Ghana: Part I. Proximate composition, fatty acids, minerals, trace elements and vitamins

Abstract

The effect of processing methods (cooking, frying and smoking) on the chemical composition of two marine fish ( Sardinella sp., Dentex sp.) and a freshwater fish ( Tilapia sp.) was studied. The proximate compositions of the fish were similar to those of other fish reported in the literature. Processing per se had no effect on the composition of fish. Smoking and cooking did not affect the fatty acid composition of the fish. The palm-kernel oil used in frying masked the fatty acid pattern in the fried fish. Freshwater fish contains high levels of n-6 fatty acids. However, similar amounts were found in the freshwater fish and the marine fish. This is probably due to the freshwater fish feeding on mosquito larvae. The fish contained appreciable amounts of Na, Ca, P and Mg. Trace elements (Fe, Cu, Zn and As) were also determined. There was no thiamine in flat sardine and tilapia, probably due to thiaminase activity. The content in Dentex sp. was low. Vitamins B 2 and B 6 were very low in all the fish.