DEVELOPMENT OF SENSORY SCORING SCHEMES FOR FARM-RAISED FISH (TILAPIA NILOTICA AND BAGRUS BAYAD)

The aim of the present investigation is to establish a guide for the post-mortem changes in sensory    characteristics of farm-raised Tilapia nilotica (T. nilotica) and Bagrus bayad (B. bayad) which are   among the most popular Egyptian freshwater fishes. Fish under experiment were kept in crushed-ice and the changes in the different sensory criteria were followed during storage by sensory evaluation of the skin surface, gills, eyes, smell and muscles stiffness of raw fish, as well as the eating quality criteria (odor, flavor and texture) for cooked samples. Numerical schemes using simplified descriptive terms were developed to make sensory evaluation more reliable and facilitate its application in industrial field. The scales were constructed into many features and the final judgement was performed according to summation of all investigated characteristics. The quality grades of raw examined samples of T.nilotica and B. bayad were categorized as excellent (grade A =10 marks) for samples stored for first three days, very good (grade B = 8 marks) for samples stored for 7days, good (grade C = 6 marks) for samples stored for 9 days, acceptable (grade C = 4 marks) for samples stored for thirteen days, while samples stored for more than thirteen days in crushed ice were considered rejected (grade E =2 marks).