Comparative study on the nutritional composition of small and large size Tenualosa ilisha of Meghna River, Bangladesh

• Energy, protein, and lipids content higher in large-sized Hilsa than the small ones. • No significant variation in vitamin content between small and large-sized Hilsa. • Higher magnesium, zinc, sodium, and potassium in small-sized Hilsa. • Both indispensable and dispensable amino acids content higher in large-sized Hilsa. • The percentage of total PUFA and total omega-3 fatty acids greater in the larger Hilsa. The study aimed to explore the comparative nutritional composition of small and large-sized Hilsa of the Meghna River in Bangladesh. Proximate composition revealed that energy (291 vs 245 kcal, p = 0.004), total protein (22.50 vs 18.14 %, p < 0.001), and total lipids (22.32 vs 19.13 %, p = 0.005) contents were significantly higher in large-sized Hilsa. The small, and large-sized Hilsa contained 89.88 and 81.69 µg/100 g of vitamin A, respectively. The content of folate (7.27 vs 7.00 µg/100 g, p = 0.041) was significantly higher in small-sized Hilsa. However, no significant variation was found in vitamin A, thiamin, riboflavin, niacin, and pyridoxine contents between small and large-sized Hilsa. Among the minerals, the contents (mg/100 g) of magnesium (19.44 vs 18.15, p = 0.008), zinc (0.96 vs 0.88, p = 0.008), sodium (55.26 vs 51.51, p < 0.001), and potassium (9.20 vs 8.60, p = 0.026) were significantly higher in small-sized Hilsa. On the contrary, the content of calcium (352.67 vs 228.00 mg/100 g, p < 0.001) was significantly higher in large-sized Hilsa compared to small-sized Hilsa. Both total indispensable amino acid, total dispensable amino acids, total PUFA and total omega-3 fatty acids contents were higher in large-sized Hilsa.