ANTIBACTERIAL AND ANTIFUNGAL PROPERTIES OF GINGER AND GARLIC ON THE SHELF LIFE OF SMOKED AFRICAN CATFISH Clarias gariepinus

This study investigates the effects of additives (ginger and garlic) on the shelf life of smoked and preserved fish and also carry out proximate composition, microbial analysis and sensory evaluation of a commercially important freshwater fish species, Clarias gariepinus. The fish samples were collected from a private fish farm in Anyigba, Dekina Local Government Area of Kogi State. Three different spices were prepared to treat the fish before smoking. The fish were smoked dried and stored. The proximate composition and sensory assessments of the smoked fish were analyzed, after 8 and 12 weeks respectively, however, from the organoleptic results of taste, colour, texture and overall acceptability of the smoked fish, samples soaked in 10% ginger and garlic concentration had the best acceptance and significantly different at (P<0.05) when compared to the non treated control after 8 weeks of storage. The microbiological analysis of stored fish were carried out to determine the sample with the lowest and highest microbial load. The results show that the fish samples treated with the two spices of ginger and garlic as preservatives prior to smoking have the lowest microbial load. In general, the investigated spices (ginger and garlic) caused a significant difference at (P<0.05) in extending the shelf-life of the smoked fish through retardation of spoilage and enhancement of the microbiological and sensory quality of Clarias gariepinus during storage as compared to the untreated samples. Samples treated with 10% ginger and garlic in brine solution has the best treatment, followed by samples treated with 10% ginger in brine solution and treated with 10% garlic in brine solution compared with the untreated samples. Such smoked fish products treated with ginger and garlic can be stored for ten (10) weeks without any yeast-mold growth. Therefore, the tested spices had a high effectiveness as antimicrobial agents and should be utilized for extending the shelf-life and enhancing quality attributes of smoked African catfish during storage.

Key words: Clarias gariepinus, ginger, garlic and Kogi State.