Grape cane waste as a source of trans-resveratrol and trans-viniferin: High-value phytochemicals with medicinal and anti-phytopathogenic applications

Grape cane waste was investigated as a potential source of high-value phytochemicals with medicinal and anti-phytopathogenic applications. Extraction yields of trans-resveratrol and trans-ɛ-viniferin from Vitis vinifera cv. Pinot Noir grape cane were 3.45 ± 0.04 and 1.30 ± 0.07 mg g−1 dw, respectively. The analyte extraction efficiencies were investigated using protic and aprotic solvents. Yields varied 22-fold over the range of solvent systems investigated, demonstrating the importance in solvent polarity and hydrogen bonding capability for efficient extractions. The current study suggests that these compounds can be quantitatively extracted from grape cane residue using low-cost, environmentally benign, and non-toxic aqueous alcoholic solvent systems such as ethanol:water mixtures. With current commercial values of trans-resveratrol and trans-ɛ-viniferin between US$ 2000 and US$ 3000 per kg, established stilbene yields from cane waste could represent an agricultural coproduct valued at US$ 2000–US$ 3000 per hectare of production. At present levels of worldwide wine grape production, the extraction of trans-resveratrol and trans-ɛ-viniferin from grape cane waste may reach a global economic value of >$30 billion.