ASSESSMENT OF PHYSICAL AND CHEMICAL CHANGES IN SOME SMOKED FISH SPECIES DURING STORAGE

Abstract

Physical and chemical changes in five smoked freshwater fish species: Heterotis niloticus, Labeo coubie, Parachanna obscura, Oreochromis niloticus and Clarias gariepinus during storage were assessed. The fish were smoked-dried to an average moisture content of 10.41 ± 0.02% and stored without preservative in plastic baskets for 56 days under ambient conditions. Samples of fish were assessed weekly for physical attributes such as colour, fragmentation, odour, taste and texture. Analyses for the proximate composition were based on changes in moisture content, crude protein, lipid and ash content. Chemical assessments were based on Total Volatile Nitrogen (TVN) , pH, Peroxide Value (PV) and Free Fatty Acid (FFA). There were significant changes in the physical and chemical characteristics of the smoked fish species as from the 6th week (42 days) of storage, except for the odour which did not differ significantly (P>0.05) during the storage period. There were significant differences (P <0.05) in the initial and final values of proximate and chemical constituents for different species of fish. The study showed that quality of smoked fish stored under ambient conditions decreases with increase in length of storage.