ABSTRACT
Peanuts have been recognized as a great tasting plant-based protein that has many different nutritional applications. The study was carried out to determine the appropriate level of peanut flour inclusion in fish ball production using catfish (Clarias gariepinus) and mackerel (Trachurus symmetricus). The peanut flour fish balls were formulated to contain 0%, 10%, 15%, 20% and 25% of full-fat peanut flour which was combined with fish and some other condiments. The minced fish and other condiments were blended and mixed homogeneously with the peanut flour and manually rolled with hands into balls of 2.28cm in diameter, the balls were steamed and also deep fried in hot vegetable oil using a fat fryer at 1700C for 3 minutes. In total, twenty samples of peanut flour fish balls were processed, ten fried samples of catfish and Mackerel fish balls and ten steamed samples of catfish and mackerel fish balls. The fried sample were placed in coded dish and presented to sixty semi-trained sensory panelists. The panelists were asked to assign appropriate score to each product tested for the characteristics of colour, taste, flavor, texture and overall acceptability of the fried fish balls prepared from combination of peanut flour. A 5-point hedonic scale was used to evaluate the sensory characteristics (colour, taste, texture, flavor and overall acceptance) of the products. Proximate analysis and microbial culture was carried out at Day 0, Week 1, and Week 2 after storage under a refrigerated condition. This excise was carried out to examine the shelf stability of peanut flour fish balls. A 5×2×2 factorial arrangement in a Completely Randomized Design (CRD) was used to accommodate all the experimental treatments in this study.
Results from the sensory evaluation showed that catfish balls with peanut flour inclusions at 15% and 25% were most acceptable. The 10% and 20% level of soy flour inclusion were moderately acceptable, thereby indicating acceptability up to 25% level of peanut flour inclusion. The most preferred colour (4.43) was observed at 0/15 inclusion level of soy/peanut flour in catfish balls. The most accepted in all treatment was catfish balls (4.20) at 0/15 soy/peanut inclusion. The least accepted (3.20) was Mackerel ball at 0/20 soy/peanut four inclusion level.
Result from proximate analyses shows that 10 % peanut flour inclusion level in fried catfish ball yielded the highest protein level. The level of crude protein (CP) and crude fat (CF) content of catfish and mackerel balls reduces with length of storage. Irrespective of colour, taste, texture, and flavor the product of Catfish were generally accepted than the products of Mackerel. Significant p < 0.05 growth of bacteria was observed after 48 hours of culture in both fried and steamed catfish and mackerel balls. The results of successful incorporation of peanut flour in catfish and mackerel balls indicate that peanut flour can be used as functional ingredient in the production of fish ball and other comminuted conventional fish products. Since Catfish is widely cultured in Nigeria, Peanut flour inclusion in Catfish balls production holds great prospects in increasing availability of cheaper Ready to Eat protein food products in Nigerian markets.
