Seasonal variation in the chemical composition and fatty acid profile of Pacific oysters (Crassostrea gigas)

The chemical composition and fatty acid profile of the tray-cultured Pacific oyster (Crassostrea gigas) were measured and compared over a 13 month period. Oysters (120–150 g) were cultured in Cork Harbour and samples taken for analysis at monthly intervals. The moisture, fat, protein, glycogen and ash contents of the flesh were analysed. The fatty acid profile of the flesh was analysed by gas chromatography. The condition indices of the oysters were determined. The chemical composition of the oysters grown in Cork Harbour was similar to literature values for the same species grown in Pacific waters. Ranges for the chemical composition (dry flesh weight basis) were: fat (7.8–8.7%), protein (39.1–53.1%), glycogen (21.6–38.9%) and ash (4.0–12.1%).