Comparative Study of the Proximate Composition and Sensory Evaluation of Fresh and Smoke-dried Fish Species from Omambala River, Anambra State, Nigeria

Abstract

This study investigates the proximate composition and organoleptic properties of fish species from the Omambala River in Anambra State. A total of 40 fresh fish samples, specifically Clarias gariepinus and Heterotis niloticus, with a mean length of 25 cm and mean weight of 380 g, were analyzed. The fish samples, initially scaled, had their viscera removed and were washed in clean water before undergoing brining. This involved immersing the fish in a 75% saturated brine solution, prepared by dissolving 27 g of NaCl in 100 ml of water for 30 seconds. The samples were then smoke-dried in a smoking kiln. Proximate composition was assessed using standard methods from the Association of Analytical Chemists (AOAC), while organoleptic properties were evaluated using a 9-point hedonic scale. Data were collated and analyzed using a two-way analysis of variance (ANOVA) with GENSTAT version 4 software, and mean separation was performed using the Least Significant Difference at a 5% probability level. Results indicated that the proximate analyses revealed an increase in all nutrient compositions after smoke-drying, except for moisture and carbohydrates, which significantly decreased from 44.58% to 14.15% and from 37.10% to 7.88%, respectively, for C. gariepinus. In the case of H. niloticus, increases were noted in ash, fiber, fat, and protein, while moisture decreased significantly (p<0.05) from 44.87% to 17.89%. Organoleptic evaluation showed a preference for C. gariepinus, which had a significantly higher overall acceptability mean score of 8.40±0.66 compared to 6.70±2.26 for H. niloticus. This research demonstrates that smoke-drying fish effectively reduces moisture content, enhances nutrient composition, and improves organoleptic properties, thereby increasing shelf life. It is recommended that both C. gariepinus and H. niloticus be hygienically smoke-dried to maximize organoleptic qualities, nutrient composition, and shelf life, ultimately yielding better economic returns. Keywords: Nutrient composition, organoleptic properties, Smoking kiln, Fish species