The Significance of Processing Techniques on the Quality of Smoked African Cat Fish (Clarias gariepinus) Using Different Energy Sources

Abstract

There is unavoidable need for fish smoking as a preservative technique to reduce rampant post harvest losses in the tropical Africa. However the imperative of healthier and quality smoked products through improved processing method were however investigated. Organoleptic and chemical assessment of African catfish collected from a reputable fish farm in Ogbomoso, Oyo state Nigeria was carried out. Eviscerated and non-eviserated fish samples were smoked using four different smoke sources: Gmelina (Gmnelina arborea), Parkia (Parkia biglobosa), Neem (Azadirachita indica) and charcoal. Overall acceptability was based on 5-point Hedonic scale (excellent (5) - poor (1). Chemical test was on Polycyclic Aromatic Hydrocarbon contents (benzo(a)pyrene, Fluoranthene, Napthalene, Acenapthalene, Chrysene and Benzo(ghi) perylene). Data were subjected to one way Analysis of Variance (ANOVA) using general linear mode (GLM) of Factorial Experimental Design and means were separated by Duncan’s multiple range tests (P<0.05). Non- eviscerated smoked African catfish samples had lower scores for colour than eviscerated smoked samples for energy sources used. Eviscerated samples had mean scores of 4.64, 3.91, 3.36 and 2.82 for charcoal, Gmelina, Neem and Parkia smoked samples respectively, much better than scores of 4.36, 2.46, 2.36 and 2.27 obtained for non-eviscerated samples. Total concentrations of polycyclic aromatic hydrocarbons (PAH) were highest in samples produced using Gmelina as smoke source and Neem for eviscerated (15.25 µg/kg) and non-eviscerated (29.43 µg/kg) samples respectively. Evisceration of fish prior to smoking enhances its sensory characteristics however; concentrations of PAHs for both eviscerated and non-eviscerated fish samples were within the recommended international standard limit.