Sensory quality assessment of fresh and smoke-dried fish in SE Nigeria

Abstract

In weekly surveys undertaken during April to September 2012, fresh and smoke-dried specimens of the three most important species of the artisanal fishery in the Cross River Estuary, namely Pseudotolithus elongatus (Bobo croaker), Chrysichthys nigrodigitatus (Estuarine catfish) and Ethmalosa fimbriata (Bonga shad), were sampled at four locations. A sensory quality assessment table for fresh fish was modified from literature and developed for smoke-dried fish. The sensory method using the human senses (sight, touch, smell, taste) can assess different factors nearly synoptically and is non-destructive. Up till now, no non-sensory method can replace the sensory method. Correlation analyses between size of the fishes and quality grades indicated that with increase in fish size the sensory quality increased. Correlation analyses between the environmental factors 'air temperature' and 'relative air humidity' showed that with increasing values of these factors the fish quality decreased. Mechanical quality impacts from the catch, transportation and processing activities were, in comparison to the bacteriological and enzymatic 'spoilage' processes, of minor significance. There was no specimen found with insect infestation. On the average for all samples, grade 2 (good quality) dominated with 59%, followed by grade 1 (very good quality) with 29% and grade 3 (fair quality) with 12%.