Grapevine cane's waste is a source of bioactive stilbenes

Grapevine canes represent a large source of waste derived from the wine industry with low added-value. In the current work, the cane stilbene composition of twenty two grape cultivars (including Vitis vinifera sativa, Vitis vinifera sylvestris and hybrid direct producers) was investigated. Ten stilbenes were identified and quantified: hopeaphenol, ampelopsin A, isohopeaphenol, piceatannol, trans-piceid, trans-resveratrol, miyabenol C, ε-viniferin, r-viniferin and ω-viniferin. Total stilbene concentration ranged from 2400 to 5800 mg/kg dry weight. Principal component analysis applied to stilbene concentration showed a separation of cultivars in five groups. Antioxidant capacity of the stilbene extracts varied from 1700 to 5300 μmol Trolox equivalent/g dry weight. No relationship was found between stilbene content and ORAC values. Finally, the effect of year on cane stilbene content was also studied in V. vinifera sylvestris grapevine. The effect of the year depended on the cultivar. Data reported sustain the use of grapevine cane byproducts as a low cost source of bioactive stilbenes for the development of natural fungicides as well as nutraceutical, as strategy for sustainable viticulture.