Abstract

Proximate composition and shelf-life studies of wild and pond-raised catfish (Clarias gariepinus) were determined using chemical, microbiological and sensory analyses. Proximate composition of both wild and pond-raised catfish showed differences in the lipid and protein levels. The pond-raised fish had higher lipid (6.30%) and protein (20.00%) than the wild fish lipid (4.48%) and protein (18.05%). Whole ungutted wild and pond-raised catfish was in good and satisfactory conditions for 17 and 22 days, respectively when stored in ice immediately after harvesting. There was no significant difference (p > 0.05) in the storage life in ice of the wild and pond-raised catfish. The descriptive sensory evaluation showed that the fish underwent changes in eyes, gills, texture, odour and general appearance. The statistical analysis showed that the correlations between the cooked odour, texture and flavour of both samples were significant at p < 0.05. The wild and pond-raised catfish showed a decline in sensory parameters during storage in ice with concomitant increase in bacteria counts and total volatile bases (TVB). The microbial population was dominated by bacilli, the counts ranged from 11.5 × 10² cfu/g to 15.4 × 10² cfu/g for wild catfish and 9.7 × 10² cfu/g to 11.1 × 10² cfu/g for the pond-raised catfish. Rejection of the catfish after 22 days was based mainly on rancid, putrid, feacal, ammoniacal and sulphide odours. TVB ranged from 2.41 to 20.50 mg/100 g for wild catfish and 2.86 to 22.88 mg/100 g for pond-raised catfish.

Key words: Sensory changes, farmed Clarias, wild Clarias, shelf-life.