Preliminary Study on the Antioxidative and Antimicrobial Effects of Fresh Garlic ( Allium sativum ) on the Shelf Life of Hot-smoked Catfish ( Clarias gariepinus )

摘要

Clarias gariepinus is a fish that is of high demand in Nigeria. However, a lot of the output from wild and aquaculture deteriorate in quality because of improper preservation methods. This study investigated the effects of fresh garlic ( Allium sativum ) on lipid oxidation and microbial growth of hot-smoked catfish ( Clarias gariepinus ). Three garlic concentrations and control (0 (control), 10, 30 and 50 g garlic kg-1 fish) were prepared, hot-smoked and stored for 28 days at ambient temperature of 20-26°C. During the storage period, the samples were subjected to weekly chemical and microbial analyses. The highest Thiobarbit uric acid (TBA) (4.32±0.39 mg malonaldehyde kg-1 sample), peroxide (12.31±2.06 milliequivalent peroxide kg-1 of sample) and microbial load (12.03±0.56 Log10 CFU g-1 fish) were recorded in the control while the lowest peroxide (6.91±1.08) and microbial count (11.15±0.43 Log10 CFU g-1 fish) occurred in sample with 50 g garlic kg-1 fish. However, the lowest TBA (3.06±0.26 mg malonaldehyde kg-1 sample) was observed in sample containing 30 g garlic kg-1 fish. The results of analyses suggest that fresh garlic possesses antioxidant and antimicrobial properties, which can extend the shelf life of Clarias gariepinus .