SIZE AND ORGAN-SPECIFIC VARIATIONS IN PROXIMATE COMPOSITION OF FRIGATE TUNA (Auxis thazard)

Abstract

Different species of tuna are well-known seafood items for their economic importance and nutritional profiles. Tuna is a cheap marine fish of Bangladesh but is not popular with consumers compared to other coastal and marine fishes. In this study, the proximate composition of tuna (Auxis thazard) was compared based on their size and body portions because size and body portions might have a significant impact on the nutritional value of the fish. Three different sizes, i.e., ≤500 g, ≤750 g, and ≥1 kg, and three different body portions, i.e., head, middle, and tail, were subjected to study for proximate analysis. Standard methods (Kjeldal and AOAC) were followed for the determination of biochemical parameters. Among different sizes of fish, the highest average percentage of protein (23.07±0.82), lipid (2.80±0.41), and ash (1.62±0.12) were calculated in the ≥1 kg size group, and among different body portions, the highest average percentage of protein (23.03±0.91), ash (1.62±0.09), and lipid (2.85±0.39) were calculated in the muscle from the middle portion of the fish. The highest average percentage of moisture (73.91±0.95) was found in the tail portion of the small-sized group. This study revealed that the comparatively larger fish and the middle portion of the body are nutritionally rich compared to the other sizes and body parts. Therefore, it is of utmost importance to raise awareness among consumers to ensure adequate nutrition at a cheap price.