Preparation of Nile tilapia (Oreochromis niloticus) waste meal for human consumption

This study aimed to prepare and characterize Nile tilapia (Oreochromis niloticus) waste meal. The experimental design consisted of three treatments (carcass meal, mechanically separated meat meal - MSM, and head meal) and five replications of each treatment. Yield, microbiological quality, pH, water activity, proximate composition, energy value, mineral composition, fatty acid profile, amino acid composition, color, and particle size fractions and the geometric mean particle diameter (GMD) analyses were performed. Data were subjected to ANOVA, and means were compared by Tukey's test at P < 0.05. Carcass, mechanically separated meat, and head meals had a protein content of 56.45%, 78.60%, and 50.33%, respectively, a lipid content of 7.16%, 13.15%, and 4.58%, respectively, and an ash content of 32.61%, 4.26%, and 38.41%, respectively. The mean yield of fish waste meals was 13%. Oleic, palmitic, and linoleic acids were the major fatty acids in the three fish waste meals, and glutamic acid, leucine, lysine, and glycine were the major amino acids. Color analysis showed that lightness (L*) ranged from 55.32 to 77.19, redness (a*) from 4.44 to 4.88, and yellowness (b*) from 4.13 to 9.51. The GMD ranged from 0.37 to 0.99 mm. The results indicate that Nile tilapia waste meals have high nutritional value and adequate pH, water activity, and microbiological quality for use in human nutrition.