1981 Volume 28 Issue 5 Pages 235-240
The conjugated lipids in the pulp of apples cv. Ralls Janet which are resistant to cold temperature and apples cv. Starking Delicious which are sensitive to cold temparature were studied with reference to mechanism of chilling injury. The following conjugated lipid components were identified; phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, phosphatidic acid, phosphatidylserine, cardiolipin, monogalactosyldiglyceride and digalactosyldiglyceride. The contents of total phospholipids and that of the respective components in Ralls Janet were larger than those in Starking Delicious. After the storage at 0°C, the contents of total phospholipid and that of the respective components decreased. The degree of decrease in Starking Delicious was larger than those in Ralls Janet. On the other hand, the contents of total sterol, free sterol, combined sterol in Ralls Janet were larger than those in Starking Delicious. Furthermore, the contents of monogalactosyldiglyceride and digalactosyldiglyceride in Ralls Janet were also larger than those in Starking Delicious. From the above results it was concluded that, higher ratio of PC/PE in Ralls Janet than that in Starking Delicious may cause the resistance to chilling injury in Ralls Janet playing a role in lowering phase transition temperature. Though many kinds of polar groups of other conjugated lipid components must be considered. The radio of unsaturated fatty acids to total fatty acids of Ralls Janet was higher than in Starking Delicious as described in a previous paper.
