DEPARTMENT OF AQUACULTURE AND FISHERIES

This study investigated the effects of different processing methods and natural spices on the proximate composition and sensory characteristics of Merluccius merluccius (Meluza). The experiment employed a 4 × 3 factorial designs consisting of four spice treatments, control (no spice), black pepper, cinnamon, and a combination of black pepper + cinnamon across three processing methods: deep frying, air frying, and smoking. Proximate and organoleptic analyses were carried out over a three-month period following standard procedures. Results revealed that both processing method and spice type significantly influenced the nutritional and sensory quality of the fish. Deep frying generally increased lipid content and enhanced juiciness, while smoking reduced moisture and increased ash concentration, reflecting mineral concentration through dehydration. Spiced samples, especially those treated with black pepper + cinnamon, showed higher carbohydrate and protein retention than controls, indicating antioxidant and preservative effects of the spices. Sensory evaluation indicated that deep-fried and spiced samples were most preferred in terms of aroma, flavour, texture, and overall acceptability. The combination of black pepper and cinnamon proved particularly effective in improving taste and aroma without compromising nutritional value. The study concludes that integrating natural spices with suitable processing methods enhances both the nutritive and organoleptic quality of M. merluccius. It is therefore recommended that deep frying with black pepper + cinnamon is suitable for the production of high-quality and consumer-preferred fish products.

This study investigated the growth performance of African catfish (Clarias gariepinus ) fry raised with a commercial feed (Coppens) and a farm made feed. Three treatments were used with three replicates per treatment. A total of 1800 fry were obtained and the experiment was conducted for a period of four weeks using experimental plastic bowls, with 200 fry per bowl. The water quality parameters (Temperature, pH, Ammonia content, Dissolved oxygen) were recorded and were within acceptable range. The effects of different diets on specific growth rate (SGR), survival rate (SR) and feed utilization were determined. Among the various experimental feeds, Treatment 1(Coppens) produced a better result compared to the others in terms of weight gained and specific growth rate. The lowest growth performance was with fry in Treatment II (Fry fed farm made feed). Estimated cost of feeding was higher in farm made feed and combined feed (N5,260), with lowest values occurring in fry fed with it Coppens (N4,600). During the experiment Coppens performed better than the other experimental feeds, it showed a higher survival rate and low pollution level. It also showed a better feed
utilization and the highest performance index..