High-Value Phytochemicals from Grape Cane Waste: Potential Value-Added Viticultural Sources of Trans-Resveratrol and Trans-e-Viniferin with Medicinal and Anti-Phytopathogenic Applications

Grape canes as agricultural waste from commercial viticultural activities represent a potentially important source of the well-known medicinal and anti-phytopathogenic stilbene compounds trans-resveratrol and trans-e-viniferin. Reports in the literature suggest that concentrations of these compounds range up to 5 mg/g dw and 2 mg/g dw, respectively, and can be quantitatively extracted from the cane residue using low-cost, environmental benign, and non-toxic aqueous alcoholic solvent systems such as ethanol:water mixtures. With current commercial values of these compounds between US$2,000 to US$3,000 per kg, established stilbene yields from cane waste could represent an agricultural coproduct valued at US$2,000 to US$3,000 per hectare of production. At the present worldwide wine grape production of 8,000,000 ha, the extraction of trans-resveratrol and trans-e-viniferin from grape cane waste would have an estimated global economic value of >$30 billion.