Bench-Scale Extraction of Stilbenoids and Other Phenolics from Grape Canes: Process Optimization, Chemical Characterization and Antioxidant Capacity

Claudia Mardones, Instrumental Analysis Departament, Faculty of Pharmacy, University of Concepcion, Concepcion, Chile
Sebastian Riquelme, Unindad De Desarrollo Tecnológico, University Of Concepcion, Concepcion, Chile
Dietrich von, Instrumental Analysis Departament, Faculty Of Pharmacy, University Of Concepcion
Carola Vergara, Instrumental Analysis Departament, Faculty Of Pharmacy, University Of Concepcion
Danilo Escobar, Unidad De Desarrollo Tecnológico, University Of Concepcion, Concepcion, Chile

There are evidence of health benefits of E-resveratrol. In Chile, more than 120 000 tons of winemaking residues (pomace, seeds, stalks, and canes) are produced each year. Grape canes are a very rich source of stilbenoids, with significant higher levels of stilbenoids than those of the other mentioned sources. Extraction parameters at bench-scale, including cane size, extraction solvent, solid:liquid ratio, temperature, and extraction time, were systematically optimized to obtain an antioxidant product from Pinot noir grape cane. Final product was characterized by HPLC-PDA-MS/MS and other analytical techniques. The main phenolic compounds in the powder were stilbenoids, flavan-3-ols, procyanidins, and flavonols with 6.53%, 4.84%, 2.11%, and 0.25%, respectively on a dry matter basis. Other chemical constituents of the product were carbohydrates, metals, and lignins. Antioxidant capacity was assessed using chemical assays (TEAC_ABTS, TEAC_CUPRAC and ORAC-FL) and endothellial cell model. The final product showed interesting reducing and protecting capacities, and potential for the nutraceutical industry