Extraction of bioactive polyphenols from grape marc by a matrix solid-phase dispersion method

Abstract

A matrix solid-phase dispersion process to extract polyphenols from grape marc, a winemaking byproduct, has been optimized by Response Surface Methodology. The dependent variables evaluated were the total polyphenols content, flavanols, hydrocynnamates, and flavonoids. The performance of the extraction method in terms of linearity and precision has also been assessed. The optimized MSPD method provides good results to extract polyphenols from white winemaking byproducts, much less studied than those from red wines, requiring low solvent consumption and being low cost and fast (15 min). The analytical instrumentation is available almost everywhere, thus becoming a ready-to-use methodology for virtually any control or winery laboratory. The optimized method has been applied to a set of bagasse samples from Albariño grapes (Vitis vinifera sp) cultivated in Galicia (NW Spain) and coming from five different types of grapevine training techniques. The vine training factor was significant on the basis of the content of the different groups of polyphenols determined in the MSPD extract