Nutritional Quality of the Mangrove Oyster, Crassostrea Tulipa, in Ghana and Hydrographic Conditions of Their Habitats

Abstract

ABSTRACT Seafood contributes significantly to food security. The present study sought to provide information on the size, meat yield, proximate nutritional composition, minerals, amino acids, fatty acids and some antioxidant properties of C. tulipa (oyster) from three water bodies in the Greater Accra, Central and Western regions of Ghana. To maximize yield and maintain good physiological conditions of the oysters, spatiotemporal variations as well as effects of environmental conditions on the meat yield, proximate, minerals and amino acid composition of the oysters were also investigated. Oysters from “Densu” estuary were the biggest in size while those from “Narkwa” lagoon were the smallest. The nutritional quality assessment qualifies C. tulipa as a highly nutritious and a potential functional food. There were no significant differences in the proximate and amino acid contents of C. tulipa from the three water bodies (P > 0.05). C. tulipa from “Whin” estuary had significantly higher Fe and Zn contents, whereas those from Narkwa lagoon had significantly higher Ca and Na contents (P < 0.05). The proximate, mineral and amino acid compositions of C. tulipa from the various water bodies varied significantly during the months of study (P < 0.05). C. tulipa had higher concentrations of essential amino acids and had no limiting amino acids. Mineral concentrations of the oysters were all within recommended limits. Environmental factors, including temperature, pH, chlorophyll-a, precipitation and salinity, had significant effects on the meat yield, moisture, ash, sodium, zinc, iron and amino acid contents of C. tulipa. C. tulipa contained phenolic compounds and showed antioxidant properties. C. tulipa oil contained high amounts of polyunsaturated fatty acids, particularly eicosapentaenoic and docosahexaenoic acids (EPA and DHA).