2001 Volume 18 Pages 63-66
Zinc (Zn) in Japanese oyster (Crassostrea gigas) was extracted and its bioavailability was evaluated. Extraction with 0.1N HCl was performed on a boiled Japanese oyster. After neutralization of the acid extract, precipitation formed was collected and used as the acid soluble fraction of boiled oyster (ASFO). Zn content of the ASFO was 3 to 10% in the dry basis. More than 70% of total Zn of raw Japanese oyster was recovered in the ASFO. In the fractionation by HPLC using TSK-GEL G2000SWXL, Zn in the ASFO was recovered in a single peak fraction with a molecular weight of about 6800. Zn level in this peak was increased by an exogenous addition of zinc chloride to the ASFO. Male weanling Wistar rats were pair-fed a low-Zn basal diet (Zn content, 1.4 ppm) or the basal diets supplemented with 5 ppm of Zn as zinc carbonate or the dry powder of the ASFO for 4 weeks. Zn contents of liver and tibia of the rats fed the diet supplemented with the ASFO were significantly higher than those of the rats fed the diet supplemented with zinc carbonate. These results indicate that Zn contained in the ASFO is more available than Zn in the form of zinc carbonate.
