Grape Seed Polyphenols and Fatty Acids of Autochthonous Prokupac Vine Variety from Serbia

Grape pomace (grape skin, seeds, and stems) represents a valuable source of bioactive compounds, thus the interest in making use of these wine waste products is increasing. Prokupac is an autochthonous Serbian variety of black grape with a long tradition in production of red wine. Identification of the superficial polyphenolic compounds by LC/MS revealed presence of 19 compounds including hydroxybenzoic acid derivatives, ellagic acid derivatives, flavan-3-ol monomers, proanthocyanidins, and flavonols. Catechin and epicatechin together with proanthocyanidins were the most abundant compounds and the highest content of phenolic compounds was determined in Prokupac clones 43/1, 40/1, and 40/2. Grape seed oil consisted of dominantly UFA (87-95 %) where methyl linoleate was the most abundant in all samples (69-81 %). Palmitic (3-8 %) and stearic acid (2-4 %) methyl esters were dominant SFA. Prokupac clone 43/3 was the most abundant in UFA (95 %) with the lowest percentage of SFA (5 %), while clones 41/1 and 43/5 had the lowest percentage of UFA (87 %) and the highest content of SFA (13 %). Favorable chemical profile of Prokupac clone seeds implicates its potential to be used as a raw material in further processing and possibility to be included as one of the quality parameters in further selection of the most interesting Prokupac clone.