Effect of heat on grape marc extract. (2018)

• Record Type: Journal Article
• Authors: Vandermeer, Charlotte; Olejar, Kenneth J.; Ricci, Arianna; Swift, Simon; Versari, Andrea; Kilmartin, Paul A.
• Is Part Of: International journal of nanotechnology. Volume 15:Number 8/10(2018)
• Page Start: 792
• Page End: 797
• Publication Date: 2018
• Subjects: winery waste -- antioxidant activity -- antimicrobial activity; 620.505
• Languages: English
• ISSNs: 1475-7435

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.