1987 Volume 34 Issue 7 Pages 462-468
It is known that chilling injury showing internal breakdown occurs in the pulp of Starking Delicious apples during cold storage, whereas the injury scarcely occurs in the Ralls Janet apples in Japan. The phosphatidylcholine (PC) and the phosphatidylethanolamine (PE) extracted from both cultivars were treated with phospholipase A2. The fatty acid composition at 1-position, 2-position and overall position of PC and PE were examined by gas-liquid-chromatography, especially considering the ratio of unsaturated fatty acids which contribute to the fluidity and flexibility of membranes. As the results, the following facts became apparent. (1) In both cultivars, the fatty acids at 1-position were mainly saturated fatty acids and the fatty acids at 2-position were mainly unsaturated fatty acids. (2) The difference of the ratio of unsaturated fatty acids to total fatty acids was slight in the PC of both cultivars just after the harvest. The ratio of unsaturated fatty acids at 2-position of PE in Ralls Janet was larger than that in Starking Delicious. (3) After six-seven months of cold storage, the ratio of unsaturated fatty acids of both cultivars decreased slightly. The unsaturated fatty acids of 2-position of PE disappeared completely. (4) The ratio of unsaturated fatty acids at 2-position in Ralls Janet decreased largely after eight months of cold storage.
