Studies on Lipids of Ume Apricot

Abstract

Lipid and fatty acid compositions of the total lipids in three parts (fleshy pericarp, stony pericarp and seed) of ume apricot, (Prunus mume SIEB. et ZUCC.) during development, maturation and processing of fruit were studied by means of thin-layer chromatography and gas-liquid chromatography. The total lipid content in seed was predominant, compared to other two parts. Total lipid contents in fleshy and stony pericarps slightly decreased (0.3→0.2%, 0.6→0.2%) during development and maturation, while that in seed increased (0.6→22.7%) considerably in the same period. Main fatty acids of the total lipids in fleshy and stony pericarps were 18:2, 18:1 and 16:0 acids, and those in seed were 18:2, 16:0 and 18:3 acids. During development and maturation, the 18:2 acid content decreased, and the 16:0 and 18:3 acid contents increased in fleshy and stony pericarps. On the contrary, in the same period, the 16:0, 18:2 and 18:3 acid contents decreased and the 18:1 acid content increased remarkably in seed. The total lipids in seed were consisted of 7 classes (triacylglycerols, 1, 2-diacylglycerols, free sterols, fatty acids, compound lipids, sterol esters and 1, 3-diacylglycerols) and the main component was triacylglycerols. A remarkble increase of triacylgycerols in seed (24.1→93.3%) was observed with decreases of other lipid classes during development and maturation. Main fatty acids of triacylglycerols in seed were 18:2, 18:1 and 16:0 acids. Saturated fatty acids were found more often at 1 and 3-positions than at 2-position of triacylglycerols. In fatty acid compositions of triacylglycerols and its 2-position, 16:0, 18:2 and 18:3 acid contents decreased while 18:1 acid content increased during development and maturation. Main molecular species of triacylglycerols in seed in late stage of maturation were UUU (74.1%. OLO, OOO and others) followed by SUU (13.0%) and UUS (10.5%). Free strols and sterol esters in mature seed were consisted of sitosterol, campesterol, stigmasterol, cholesterol and isofucosterol and main component was sitosterol.