Effect of post-slaughter time intervals on the quality of the African catfish, Clarias gariepinus (Burchell, 1822).

摘要

Effects of post-slaughter time were investigated on the quality of fresh and hot-smoked African catfish (Clarias gariepinus). A total of 104 catfish (average wt. 700 +or- 7.0 g) were slaughtered and smoked. 10 freshly slaughtered samples were selected for sensory analysis at 0, 4, 8 and 12 h after slaughter. 3 fresh and 3 smoked fish were selected for physicochemical and microbiological analysis. Microbial loads increased significantly with time after slaughter (P < 0.05) from 5.52 +or- 0.03 to 5.87 +or- 0.03 log cfu/g in fresh fish and 2.04 +or- 0.02 to 3.09 +or- 0.1 log cfu/g in smoked fish samples. Bacteria identified in fresh fish included Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Bacillus spp. and Staphylococcusaureus, whereas those identified in smoked fish included E. coli, S. aureus and Bacillus spp. Protein and ash contents of fresh fish samples increased and moisture contents decreased with time after slaughter, but lipid contents remained unchanged. However, protein, lipid and ash contents of smoked fish significantly decreased with increasing time after slaughter (P < 0.05), whereas moisture content increased significantly (P < 0.05). Result suggest that in order to maintain quality, African catfish should be smoked immediately after slaughter.