Flavonol Profiles for Grape and Wine Authentication

摘要

Flavonols are a class of flavonoid compounds with a potential use as chemical markers for cultivar authentication of grapes and their wines, like anthocyanins do in the case of red grape and wine. Flavonols have the advantage of occurring in both red and white grapes and wines. Red grape flavonols are 3-O-glucosides, 3-O-galactosides, and 3-O-glucuronides of six flavonoid structures (kaempferol, quercetin, isorhamnetin, myricetin, laricitrin, and syringetin). In contrast, white grapes do not contain any flavonol derived from myricetin, laricitrin and syringetin. In addition, grapes usually contain traces of rutin (quercetin 3-O-rutinoside). Grape flavonol profiles are characteristic enough to allow statistical differentiation among grape cultivars. In wine, the original grape flavonol 3-O-glycosides suffer partial hydrolysis and the use of flavonol profiles for cultivar authentication only lead to good results after expressing the results as aglycone-type flavonol profiles.