The Anti-Oxidative and Anti-Fungal Effects of Garlic (Allium sativum) Products on the Shelf-Life of Hot Smoked Clarias gariepinus (Burchell, 1822)

Abstract

Abstract

Garlic powder was obtained through dry blending and sun-drying while garlic paste was produced by hand grating. Garlic oil was extracted from fresh garlic through hydro-distillation process. Ninety freshly killed Clarias gariepinus(250±20 g were procured and were gutted, washed, and spices with garlic paste, powder and oil. Fifteen fish samples were treated with garlic paste at three different concentrations (0, 10 and 30 g garlic paste/kg of fish). Each garlic paste concentration was applied to five fish. A similar process was used for the treatment of gutted fish samples in garlic powder (3 experimental units) and garlic oil (3 experimental units). The experimental setup is as follows: fifteen fish samples were spiced with garlic paste at 0 grams garlic paste/kg of fish (control), 10 grams garlic paste/kg of fish and 30 grams garlic paste/kg of fish. Another fifteen gutted fish samples were spiced with garlic powder at a concentration of 0 grams garlic powder/kg of fish (control), 5 grams garlic powder/kg of fish and 10 grams garlic powder/kg of fish. The last set of experimental unit had fifteen gutted fish samples treated with garlic oil at a concentration of 0 ml garlic oil/kg of fish (control), 1 ml garlic oil/kg of fish and 1.5 ml garlic oil/kg of fish. The treatments were replicated twice. The fish o were smoked using a gas-powered smoking kiln at 85 C for 6 hours. Thiobarbituric acid (TBA), peroxide value (PV), microbiological and sensory analyses were performed to investigate quality changes and to determine the shelf stability of the products. The lowest TBA(23.02 ± 3.14 MDA/kg) and Peroxide (10.46 ± 2.31 mEq/kg) values were recorded in 1.0 ml garlic extract (oil) treated samples, while the highest TBA(31.27 ± 5.01 MDA/kg) and peroxide value (14.25 ± 3.41 mEq/kg) occurred in the control. However, TBA value, peroxide value and microbial count were not significantly different (P>0.05) among the treatments. Organoleptic assessment among treatments was significant (p<0.05). The study showed that garlic products could extend shelf life of Clarias gariepinus.