Winery wastes were used as a source of polyphenolics to increase antioxidant capacity.
What is it about?
The recovery of antioxidants from complex winery and grapevine by-products into Vitis vinifera must offers new opportunities for wine grapes by the development of a new, enriched fruit juice. However, this demands the search for new valorization methods to get hold of additional antioxidant compounds. The objective of this study was to find a novel functionality for grape pomace, grapevine leaves and canes by its reuse as a functional matrix for the extraction of antioxidants into grape must. After thermomaceration, 22 polyphenols were identified by high performance liquid chromatography and mass spectrometry. Grape pomace was a good source of anthocyanins (malvidin-3-glucoside), while flavonols (quercetin-3-hexoside) and phenolic acids (caftaric acid) were the main phenolic compounds in leaf extracts. Catechin dimer was the only polyphenol compound present in all matrices. Enriched grape juice comprised by 40:20:40% (v/v/v) of pomace, leaf and cane extracts, yielded an oxygen radical absorbance capacity of pirogallol red and fluorescein ratio of 0.70 indicating that the reactivity of antioxidants present in enriched grape juice was at least as efficient as other polyphenol-rich beverages. Thus, pomace, leaves and canes supply additional polyphenols to grape must that results into a beverage with promissory antioxidant activity and potential health benefits.
Why is it important?
Increasing antioxidant potential of grape must may result in a beverage with similar health characteristics as red wines. At the same time, a use of winery wastes and grapevine by-products has been proposed.
The following have contributed to this page: Dr Johannes P.F. de Bruijn and Ignacio Serra Stepke