POTENTIAL OF ROMANIAN VINE WASTES AS A NATURAL RESOURCE OF TRANS-RESVERATROL

Abstract

The methods for producing natural resveratrol are of big interest due to the numerous health benefits of this substance and its increasing use in functional foods, food supplements and para-pharmaceutical preparations, especially with the recent permission of resveratrol as a novel food ingredient in the European Union (Commission Implementing Decision (EU) 2016/1190). Since annually a large amount of waste is produced in vine pruning, the aim of this study was to evaluate the potential of vine shoots from ten grape varieties (Fetească Albă, Fetească Neagră, Muscat Ottonel, Muscat de Hamburg, Tămâioasă, Coarnă Neagră, Merlot, Cabernet Sauvignon, Fetească Regală and Burgund Mare) from two different locations to be used as a natural source of trans-resveratrol. To reach this goal, two different solvents were explored, two different storage periods, three different time of collecting of samples in two different years. Moreover, a correlation between the type of vine (red or white) and trans-resveratrol content was analyzed. Maceration solvent diethyl-ether:ethanol, 1:4 ratio, showed a higher yield of extraction of trans-resveratrol than methanol 80%. Increasing the storage time by another 6 weeks positively affected the concentration of resveratrol for 5 samples, and for another 7 negatively. The time of collecting the samples had a high influence on the resveratrol content on shoots samples, highlighting the fact that autumn is the optimal time for harvesting. No correlation could be established among the grape varieties (red or white) and the trans-resveratrol content. The highest concentration of resveratrol was recorded for the Fetească Neagră variety – 2367.37 mg/kg. D.W.