Chemical Composition, Microbial Content and Sensory Evaluation of Smoked Farmed Catfish Clarias gariepinus (Burchell, 1822) Raised Under Different Culture Systems in Ibadan, Nigeria

Abstract

This paper examined chemical composition, microbial content and sensory evaluation of smoked farmed catfish Clarias gariepinus raised in different culture systems with a view to determining its quality and shelf life at ambient temperatures (28 ±2^oC) and relative humidity (75% - 85%). Six farms with the two most common fish culture systems (3 concrete tanks (CTs) and 3 earthen pond (EPs) were selected based on frequency of harvest and yield. Fish samples (500±10g) obtained from these farms after 4 months of culture were processed, smoked, packaged and stored for 36 weeks. The values of moisture content, ether extract, crude protein, ash, crude fibre and nitrogen free extract obtained from smoked farmed C. gariepinus during storage ranged from 4.67% – 21.69%; 21.00% - 20.79%; 65.02% - 49.35%; 5.51% - 0.03%; 1.00% - 1.37% and 2.81% - 6.60%, respectively. Highest total viable count (TVC) in processed catfish from both systems (1.27x10⁶±0.01cfu/g) were obtained in the 36^th week of storage. Storage time has significant effects (p<0.05) on TVC. Smoked fish from local fish processor (LFP) had highest TVC >10⁷cfu/g. Best sensory scores in processed catfish were 7.0±0.01; 6.5±0.01 and 5.0±0.03 at 24 week of storage for fish from EP, CT and LFP, respectively. All quality and safety indices were within International Commission of Microbiological Specification for Foods acceptable limits.

Keywords: Total viable count, smoked fish, quality changes, protein content, texture