Changes in lipid components of seeds during growth and ripening of cacao fruit

The biosynthesis of lipid in maturing cacao seeds was studied over two cropping seasons (1975\s‐1976) in Brazil using hybrids produced by cross pollination of Catongo with Amelonado cultivars. Seeds were collected at intervals between seed solidification (110\s‐120 days postpollination) and harvesting of ripe fruits at 175\s‐180 days. Lipid accumulated in seeds at a rapid, linear rate after the seeds solidified until near the beginning of ripening, when lipid build up proceeded at a greatly reduced rate. Triglyceride was the major lipid component at all stages of maturity, increasing from 69% to 96% of the total lipid over the period studied. The contributions of other lipid components to total lipids became less prominent as fat accumulated in seeds. However, on an individual seed basis their mass increased throughout development, except for phospholipids and diglycerides, which decreased on a mass/seed basis in the latter stages of fruit maturation. Since the rate of triglyceride production slowed at about the same time, the reduced amounts of phospholipids and diglycerides indicate the classical Kennedy pathway for triglyceride synthesis is operative in seeds of cacao. Fat present early in seed development was more unsaturated than typical cocoa butter of commerce. However, as lipid deposited during the period of active lipid synthesis, starting at about 130 days postpollination, a normal fatty acid composition was quickly established and did not change materially thereafter.