cis‐Vaccenic acid in mango pulp lipids

A peak corresponding to a methyl octadecenoate other than oleate has been detected on the capillary gas chromatogram of the methyl esters of mango pulp fatty acids. This octadecenoate was isolated by silica gel and argentation column chromatography, high performance liquid chromatography and argentation thin layer chromatography, and then analyzed by infrared, nuclear magnetic resonance and gas chromatography‐mass spectrometry, chromatographic separations and oxidative degradation. These analytical data proved that the octadecenoic acid was cis ‐vaccenic acid ( cis ‐11‐octadecenoic acid). The concentration of this acid in total octadecenoic acids ranged from 35% to 50% in the pulp of mangoes from Fiji, Mexico, the Philippines and Taiwan. cis ‐Vaccenic acid was revealed to be one of the major component fatty acids of non‐polar lipids (mainly triacylglycerols), glycolipids and phospholipids in mango pulp. The glycolipids contained cis ‐vaccenic acid (ca. 20%) in higher concentration than oleic acid (ca. 15%). A trace amount of cis ‐vaccenic acid (0.5%) was detected in the total lipids of mango seeds. Profile of fatty acid composition of mango pulp lipids (0.2–0.3 wt% of wet pulp) was characterized by the presence of n−7 acid isomers, cis ‐vaccenic acid and palmitoleic acid, and unusual mono‐ and dienoic positional isomers.