LC-MS/MS analysis of free fatty acid composition and other lipids in skins and seeds of Vitis vinifera grape cultivars.

Lipids are important constituents of plant and animal cells, being essential due to their biological functions. Despite the significant role of these compounds in grape berries, knowledge of grape lipid composition is still limited. This study addresses the free fatty acid composition and other lipids in skins and seeds of several Vitis vinifera grape cultivars using LC-MS/MS. A different profile of free fatty acids was determined in the grape tissues, showing a higher proportion of unsaturated fatty acids in seeds (ca. 60%). Lignoceric acid was one of the main free saturated fatty acids found in grape skins, together with palmitic and stearic acids. Berry skins showed similar ranges of C18-unsaturated fatty acids, whereas linoleic acid was predominant in the seed fatty acid composition. Higher content of glycerophospholipids was determined in grape seeds. Uvaol and oleanolic acid were only quantified in skins (1.5-3.9 and 38.6-57.6 mg/kg fresh weight, respectively). These preliminary results suggest a certain diversity in grape lipids according to their location in the berry tissues and cultivar, providing useful information for the fermentation process due to their role in wine sensory profile and yeast growth.