Quality Assessment of Fresh and Frozen Clarias Gariepinus and Tilapia Zilli found in Tagwai River and Shiroro Dam in Niger State, Nigeria

Abstract

Fresh samples (30 each) of Clarias gariepinus and Tilapia zilli were purchased from fish mongers at the fish landing sites of Tagwai and Shiroro dams in Niger State. Of this nomber, 10 samples of each species were assessed fresh and 10 were frozen for one week, while the remaining 10 samples of each species were frozen for two weeks. Some organoleptic, chemical and microbial parameters were assessed. The organoleptic assessment was done by a five-man panel. The scores for fillets indicate that fresh specimens of both species stored at ambient temperature started deteriorating in quality between 8 and 12 hours of storage. The fish became unacceptable after the 12 hours of storage. From both organoleptic and chemical assessment of fish stored at -3° C, the limit of acceptability of Clarias gariepinus and Tilapia zilli was between seven and fourteen days. The organoleptic assessment appeared to be more reliable than the chemical and microbial indices. However, there was no significant difference (P<0.05) between the two species investigated.