The Chemical Composition of Giant Clam (Tridacna gigas) Tissues

Abstract

Mantle tissue and adductor muscle from 7.5-year old giant clams, Tridacna gi­gas, were analyzed for their water, protein, fat, fiber, cholesterol and ash contents and their amino acid and fatty acid compositions. Water made up 95.2% and 74.4% of the fresh wet weight of mantle tissue and adductor muscle, respectively. The chemical composition of T. gigas tissues is generally similar to that of other bivalves. Both mantle tissue and adductor muscle had high protein contents of 44.5% and 57.0%, respectively. Both tissues had l ow fat and cholesterol contents of 3.57% and 0.05%, respectively, for mantle tissue and 1.95% and 0.032%, respectively, for adductor muscle. On a wet-tissue basis, the fat and cholesterol contents of T. gigas were sig­nificantly lower than reported for whole tissues of other bivalves. Both tissues contained high levels of polyunsaturated fatty acids (PUFA) which made up 45.0% of the total fatty acids in mantle tissue and 45.8% in adductor muscle. As a proportion of the total fatty acids, levels of 20:Sn-3 and 22:6n-3, which are considered important in human nutrition, are lower in T. gigas tissues than reported for some other bivalves.