QUANTITATIVE QUALITY TESTS FOR SOUTH AFRICAN FISH MEAL: AN INVESTIGATION INTO THE VALIDITY OF A NUMBER OF QUALITY INDICES

Fish meals from different factories were analysed for moisture, protein, and fat content. Pre-processing spoilage of the fish was assessed by determining total volatile basic nitrogen (TVBN), free fatty acid (FFA) and phospholipid (PL) contents of the meals. Heat damage during drying was assessed by determining polyunsaturated fatty acid (PUFA) content of the meal lipids. Results indicated that the PL level of the meals is a better indicator of pre-processing fish spoilage than either its TVBN or FFA content. The PUFA content of the meal lipids proved to be an excellent guide towards detecting heat abuse during drying of the meals. No evidence was found for concluding that steam dryer causes more heat damage to meals than flame dryer.