Studies on Greening of Canned Shellfishes

Part VII. On the green pigments of canned oysters cultivated in Matsushima bay

Abstract

The greening of canned oysters was found first in canned oysters cultivated in Matsushima bay about ten years ago and also found in canned oysters cultivated in Hiroshima bay a few years ago.
According to reseachers or canned manufactures the greening of canned oysters cultivated in Matsushima bay differs from the greening of those cultivated in Hiroshima bay.
For the purpose of deciding whether the greening of canned oysters cultivated in Matsushima bay and in Hiroshima bay are based on different pigments or not, the green pigments of canned oysters cultivated in Matsushima bay were extracted with hydrochloric acid-acetone mixture and further purified by the method described in case of oysters of Hiroshima bay.
The green pigments of canned oysters cultivated in Matsushima bay were separated into five components. Judging from the experimental results obtained by physico-chemical reaction, absorption spectral analysis, thin layer chromatography, solubility test, infra-red spectral analysis and micro elemental analysis, it was concluded that the green pigments of canned oysters of Matsushima bay are alike to those of oysters of Hiroshima bay and its greening is derived from chlorophyll a derivatives.