Amino Acid and Fatty Acid Composition of the Muscle Tissue of Yellowfin Tuna (Thunnus Albacares) and Bigeye Tuna (Thunnus Obesus)

Abstract

The nutritional compositions of yellowfin tuna (Thunnus albacares) and bigeye tuna (Thunnus obesus) were investigated. The two species had high protein (23.52 – 23.72%) and low fat content (1.93 – 2.06%). No significant differences were found in the moisture, protein, fat, and ash contents between the two tuna fish species. Eighteen amino acids were identified in both fish species, and glutamic acid was the most predominant (12.45% in yellowfin tuna and 11.28% in bigeye tuna). The total amino acid (TAA) content ranged between 82.66% and 84.49% (dry weight). The ratios of essential amino acids (EAA) to TAA in yellowfin tuna and bigeye tuna were 44.95% and 45.64%, respectively. With the exception of tryptophan, the other EAA scores were >100 %. The major fatty acids were C16:0, C18:1, C22:6 (DHA), and C18:0. Yellowfin tuna had a higher concentration of DHA (20.22%, % of total fatty acids), however, no significant differences in C20:4 (ARA) and C20:5 (EPA) were found between the two tuna fish. The n-3/n-6 ratios of yellowfin tuna and bigeye tuna were 3.29 and 4.56, respectively. This study shows that these tuna species have high nutritional qualities.