Composition and Detailed Characterization of Amino Acids, Peptides, Proteins, Fatty Acids, and Minerals of Tuna Trimming Fish Meal

Tuna processing byproducts hold significant nutritional value, though their quality can vary based on species, size, environment, and processing level. This study aimed to evaluate the nutritional value of tuna trimming fish meal raw material for developing high-value products. The analysis showed that the material is 56.90% protein, 21.30% ash, 12.39% lipid, 6.40% moisture, and 0.88% carbohydrate. It contains essential amino acids, including methionine and lysine. The profiles of proteins and peptides were determined using nano-flow liquid chromatography-tandem mass spectrometry (nanoLC–MS/MS), which revealed that the most abundant proteins are myosin and collagen. Of 3204 nonredundant peptides identified, 17 peptides have high bioactive potential, including 7 with antioxidant properties. Fatty acid profiling showed higher levels of saturated fatty acids (SFA) compared to those of polyunsaturated fatty acids (PUFA). Among PUFA, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) were present at 20.98% and 4.46%, respectively. Mineral analysis indicated high levels of macro- and microelements, such as calcium and phosphorus. Washing the tuna trimming fish meal at different pH levels decreased ash and increased the level of essential amino acids, highlighting tuna trimming fish meal as a valuable resource for various applications.