NITTA Yumiko    Department   Hiroshima shudo University  The Faculty of Health Sciences    Position   Professor
Date	2022/06/11
Presentation Theme	Nutrition of the oysters aqua-cultured in the ecosystem of the Hiroshima Regional Urban Area
Conference	22ND IUNS-ICN 2022 TOKYO, JAPAN (22nd International Congress of Nutrtion in Tokyo, Japan)
Promoters	THE INTERNATIONAL UNION OF NUTRITIONAL SCIENCES
Conference Type	International
Presentation Type	Poster
Contribution Type	Collaborative
Venue	Tokyo, Japan
Publisher and common publisher	◎Yumiko Nitta, Yumiko Miki
Details	Research background: Could the ecosystem including oyster culturing area produce oyster meat with higher quality, sustain better human health and improve preventive medicine? The law, Revision of the Law Concerning Special Measures for Conservation of the Environment of the Seto Inland Sea and Modification of the Basic Plan for the Conservation of the Environment of the Seto Inland Sea acted in 20115. Evaluation of the oysters have been performed nutritionally. Materials and Methods: Study areas are in the Hiroshima Regional Urban Area and Hiroshima Bay, Japan. Amino acid components in oyster meat were examined. And, two heavy metals, Cd and Zn, were measured in the marine sediments, river sediments, oyster meat, and oyster shells. Results: The cultured oysters contained carbohydrate and Zn with high levels. The total concentration of glucogenic amino acids was 69.6% of the total amino acid when measured by molecular volume. The sediment below oyster culturing rafts of Hiroshima Bay contained Zn and Cd: the mean value of Zn exceeded the maximum limit of sediment acceptable, and that of Cd was as high as those of 9 years ago. Commercially available oysters contained Zn in meat with as high levels as those of 50 years ago, which were as those of sediment and in shell as one tenth of the sediment. Oyster shell waste contained 0.005~0.32 mg/kg of Cd, which were as high levels as those in their meat. Conclusion: The fundamental solution would be to regain the sediment of lesser concentrations of Zn and Cd, which would restore the healthy Hiroshima Bay for oyster culturing, decrease viral infections through oyster meat, and conserve the ecosystem with landscape level.