Nutritional composition and total collagen content of two commercially important edible bivalve molluscs from the Sea of Japan coast

The study aimed to evaluate the chemical composition and nutraceutical potential of two commercially significant edible bivalve mollusc species (Anadara broughtonii and Mactra chinensis). The edible parts (motor muscle, mantle and adductor) of these molluscs were analyzed for their proximate composition, collagen content, amino acid profile, chemical score and elemental constituents. Both molluscs had low fat content (2.43–6.91 g/100 g dry weight), and protein (55.36–68.01 g/100 g dry weight) and carbohydrates (11.36–20.37 g/100 g dry weight) were their main components. Total collagen content of the edible bivalve molluscs varied from 30.5 to 39 mg/g wet weight, accounting for approximately half of their total protein content. Among amino acids, glycine, glutamate, aspartic acid, alanine, leucine, lysine and arginine were present at high levels in the edible parts of both bivalve molluscs, while the major elements present were sodium, potassium, magnesium, calcium, iron, zinc and nickel. Having high-quality protein content, edible bivalve molluscs could be excellent sources of nutritive ingredients and, after further study, may find applications in nutricosmetics and functional foods.