Etude de la composition lipidique du raisin, Vitis vinifera L.: <p>Evolution au cours de la maturation et localisation dans la baie</p>

Abstract

Lipid composition of grapevine berries, Vitis vinifera L.:
Changes during maturation and localization in the berry

Quantitative determinations in four grapevine varieties, Vitis vinifera L., gave evidence that the level of fatty acids in mature be rries was around 0.045 %, for t he main part unsaturated acids. Linoleic, pa lmit ic, linolenic and oleic acids were the most abundant, followed by stearic and behenic acids . No free fatty acids were found. Phospholipids formed the largest fraction prior to neutral and glycolipids. Glycolipids showed a high level of linolenic acid, while in phospho- and neutral lipids linoleic acid was highest. In the three fractions, polyunsaturated acids made up more th an half of total fatty acids. No differences were found between grape varieties. During grape maturation, changes in fatty acid levels were low, except for linolenic acid, which decreased consistently, this decline was concerned with neutral and glycolipids. Consequently, the potential of herbaceous flavour decreased progressively during berry maturation. Fatty acids were 1.5-3 times lower in pulp than in skin; thus, the skin can contribute to a large enrichment of fatty acids in juice, polyunsaturated derivatives, especially linolenic acid, being highest. In consequence, the presence of a !a rge part of grape herbaceous flavour potential in the skin was confirmed. Fatty acid patterns were s imilar in pulp and in skin, with more than half consisting of polyunsaturated compounds. There were a lso identical patterns for other lipids such as phospholipids, which were t he most abundant, followed by neutral and glycolipids.