Optimization of protein content of fish feed formulated using compositions of groundnut cake, milk powder, lemon grass and corn cob

This work presents the optimization of protein content of fish feed formulated using compositions of groundnut cake, milk powder, lemon grass and corn cob. The ingredients (precursors of the feed) were characterized in terms of proximate analysis, and they were used for the formulation fish feed. Functional groups of the feed were ascertained using Fourier transform infrared spectroscopy. The protein content of the feed was optimized using response surface methodology. From the analyses of the results, ash contents of 2.78 %, 6.74%, 3.53%, and 4.91% were recorded for groundnut cake, milk powder, lemon grass and corn cob respectively. It indicates high content of minerals. Also, there high protein contents, 21.69%, 35.13%, 31.02% and 3.40% for groundnut cake, milk powder, lemon grass and corn cob samples respectively, which show that the samples are suitable for the fish feed formulation. The major functional groups of the fish feed are; C-H stretch, O-H stretch, N-H symmetric, C-H stretch, ≡C-H stretch, N-H bend, CH(CH3)2, C-F stretch, C-O-C sym, =C-H bend and C-H bend. It revealed the presence of alkane and alkyls and carboxylic acids. Heteroatoms (O, N) are present in the feed. Quadratic equation represents the relationship between the feed protein content and the compositions of the feed raw materials. The predicted protein content (33.68%) compare significantly with the experimental protein content of 33.88%, with percentage deviation of 0.59% (< 5%). Thus, the feed’s protein content obtained at appropriate quantities of groundnut cake, milk powder, lemon grass and corn cob was successfully optimized.