Macrowine 2021
IVES 9 IVES Conference Series 9 Dissecting the polysaccharide‐rich grape cell wall matrix during the red winemaking process, using high‐throughput and fractionation methods

Dissecting the polysaccharide‐rich grape cell wall matrix during the red winemaking process, using high‐throughput and fractionation methods

Abstract

Limited information is available on grape wall-derived polymeric structure/composition and how this changes during fermentation. Commercial winemaking operations use enzymes that target the polysaccharide-rich polymers of the cell walls of grape tissues to clarify musts and extract pigments during the fermentations. In this study we have assessed changes in polysaccharide composition/ turnover throughout the winemaking process by applying recently developed cell wall profiling approaches to both wine and pomace polysaccharides. The methods included gas chromatography for monosaccharide composition (GC-MS), infra-red (IR) spectroscopy and comprehensive microarray polymer profiling (CoMPP) using cell wall probes. CoMPP performed on the concentrated soluble wine polysaccharides showed a fraction rich in rhamnogalacturonan I (RGI), homogalacturonan (HG) and Arabinogalactan proteins (AGPs). We also used chemical and enzymatic fractionation techniques in addition to CoMPP to understand the berry deconstruction process more in-depth. CoMPP and gravimetric analysis of the fractionated samples showed that thefermentation-derived pomace could be divided into a pectin-rich fraction (pulp tightly-bound to skins) containing HG, RGI and AGPs; and secondly, a xyloglucan-rich fraction (mainly skins). Interestingly this fraction was found to include pectins consisting of tightly-associated and highly methyl-esterified HG and RGI networks. A unique aspect is datasets suggesting that enzyme-resistant pectin polymers ‘coat’ the inner xyloglucan-rich skin cells. This data has important implications for developing effective strategies for efficient release of favourable compounds (pigments, tannins, aromatics, etc.) from the berry tissues during winemaking. This study provides a framework to understand the complex interactions between the grape matrix and carbohydrate-active enzymes to produce wine of desired quality and consistency.

Publication date: May 17, 2024

Issue: Macrowine 2016

Type: Article

Authors

John Paul Moore*, Jonatan Fangel, Melane Vivier, William Willats, Yu Gao

*Stellenbosch University

Contact the author

Tags

IVES Conference Series | Macrowine | Macrowine 2016

Citation

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