Lipid of Fruits and Vegetables and its Physiological and Qualitative role

Part II. Changes of phospholipid during maturation of tomato fruits cultured in the open

Abstract

Changes of contents of phospholipids (PL) and their fatty acid composition in tomato fruits, cultured in the open were investigated during ripening and storage periods.
I) Total amount of PL appeared to increase during the early stage of maturation. When fruits were harvested at breaker stage and stored at 20°C, PL contents Showed remarkable decrease 4-5 days after harvest, corresponding to the time of climacteric peak of respiration, then was followed by gradual decrease.
II) Phospholipids were separated with thin layer chromatography and determined with Fiske and Subbarow's method. The phosphatidyl choline (PC) and phosphatidyl ethanolamine (PE) were found as the major constituents showing 60% of the total PL. The PC showed the same tendency as the change of total PL during the ripening and the storage. The PE content decreased 4-5day after harvest and after that tended to increase. Other compositions did not show marked change.
III) The fatty acid composition of total PL, PC, PE, ph. inositol and cardiolipid were analyzed with gas-liquid chromatography. Oleic acid (C_18:1), linoleic acid (C_18:2), linolenic acid (C_18:3) and palmitic acid (C_16:0) were determined as the main fatty acids of the PL and, as a whole, saturated fatty acid increased with progress of storage period. It appeared that higher unsaturated fatty acids, such as C_18:3, C_18:2, C_18:1, were metabolised rapidly during the first part of storage period.