Title: Effect of heat on grape marc extract

Authors: Charlotte Vandermeer; Kenneth J. Olejar; Arianna Ricci; Simon Swift; Andrea Versari; Paul A. Kilmartin

Addresses: School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand; Department of Agriculture and Food Sciences, University of Bologna, Piazza Goidanich 60, Cesena, Italy ' School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand; Department of Agriculture and Food Sciences, University of Bologna, Piazza Goidanich 60, Cesena, Italy ' School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand; Department of Agriculture and Food Sciences, University of Bologna, Piazza Goidanich 60, Cesena, Italy ' School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand; Department of Agriculture and Food Sciences, University of Bologna, Piazza Goidanich 60, Cesena, Italy ' School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand; Department of Agriculture and Food Sciences, University of Bologna, Piazza Goidanich 60, Cesena, Italy ' School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand; Department of Agriculture and Food Sciences, University of Bologna, Piazza Goidanich 60, Cesena, Italy

Abstract: Food spoilage is a major global concern, and solutions involving green active packaging are being actively sought. Grape marc is a by-product of the wine industry, and is rich in tannins with antioxidant and antimicrobial activity. For use in melt blending with plastics such as polyethylene, the impact of heating a grape tannin extract to 150°C was evaluated. While there was a loss in total phenolic content after heating, this did not lead to a loss in functionality. There was an improvement in antioxidant activity from 65.3 ± 0.6% to 70.8 ± 1.3% DPPH radicals scavenged, and a significant improvement in antimicrobial activity. Against E. coli, the activity improved by 35%, while against S. aureus there was improvement of 60%. FT-IR analysis showed no degradation of the extract when heated to 150°C, other than some disruption of hydrogen bonds within the condensed tannin network.

Keywords: winery waste; antioxidant activity; antimicrobial activity.

DOI: 10.1504/IJNT.2018.098450

International Journal of Nanotechnology, 2018 Vol.15 No.8/9/10, pp.792 - 797

Available online: 20 Mar 2019 *

Full-text access for editors Access for subscribers Purchase this article Comment on this article