Dissecting the polysaccharide-rich grape cell wall matrix using recombinant pectinases during winemaking

• Recombinant pectinases were used during the winemaking process.
• CoMPP datasets were analysed using multivariate methods.
• Pectin lyase showed strong de-pectination action on grapes.
• Other pectinase combinations unraveled but did not de-pectinate.
• A hypothetical grape berry cell wall model was proposed.

The effectiveness of enzyme-mediated-maceration in red winemaking relies on the use of an optimum combination of specific enzymes. A lack of information on the relevant enzyme activities and the corresponding polysaccharide-rich berry cell wall structure is a major limitation. This study used different combinations of purified recombinant pectinases with cell wall profiling tools to follow the deconstruction process during winemaking. Multivariate data analysis of the glycan microarray (CoMPP) and gas chromatography (GC) results revealed that pectin lyase performed almost as effectively in de-pectination as certain commercial enzyme mixtures. Surprisingly the combination of endo-polygalacturonase and pectin-methyl-esterase only unraveled the cell walls without de-pectination. Datasets from the various combinations used confirmed pectin-rich and xyloglucan-rich layers within the grape pomace. These data support a proposed grape cell wall model which can serve as a foundation to evaluate testable hypotheses in future studies aimed at developing tailor-made enzymes for winemaking scenarios.