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

Area of Science:

• Enology
• Plant Biochemistry
• Biotechnology

Background:

• Enzyme-mediated maceration is crucial for red winemaking, but optimal enzyme combinations and grape cell wall structures are not fully understood.
• Limited knowledge hinders the development of effective enzyme treatments for wine production.

Purpose of the Study:

• To investigate the effectiveness of different pectinase combinations on grape cell wall deconstruction during winemaking.
• To profile the polysaccharide composition of grape cell walls and understand enzyme activity impacts.

Main Methods:

• Utilized purified recombinant pectinases (pectin lyase, endo-polygalacturonase, pectin-methyl-esterase) in various combinations.
• Employed cell wall profiling tools, including glycan microarray (CoMPP) and gas chromatography (GC).
• Applied multivariate data analysis to interpret enzyme activity and cell wall deconstruction.

Main Results:

• Pectin lyase demonstrated significant de-pectination capabilities, comparable to commercial enzyme mixtures.
• A combination of endo-polygalacturonase and pectin-methyl-esterase unraveled cell walls but did not achieve de-pectination.
• Confirmed the presence of distinct pectin-rich and xyloglucan-rich layers in grape pomace cell walls.

Conclusions:

• The study provides insights into grape cell wall structure and enzyme interactions during maceration.
• A proposed grape cell wall model can guide future research in developing targeted enzymes for winemaking.
• Findings support the potential of pectin lyase as a key enzyme for optimizing red wine production.