Cell
wall profiling technologies were used to follow compositional
changes that occurred in the skins of grape berries (from two different
ripeness levels) during fermentation and enzyme maceration. Multivariate
data analysis showed that the fermentation process yielded cell walls
enriched in hemicellulose components because pectin was solubilized
(and removed) with a reduction as well as exposure of cell wall proteins
usually embedded within the cell wall structure. The addition of enzymes
caused even more depectination, and the enzymes unravelled the cell
walls enabling better access to, and extraction of, all cell wall
polymers. Overripe grapes had cell walls that were extensively hydrolyzed
and depolymerized, probably by natural grape-tissue-ripening enzymes,
and this enhanced the impact that the maceration enzymes had on the
cell wall monosaccharide profile. The combination of the techniques
that were used is an effective direct measurement of the hydrolysis
actions of maceration enzymes on the cell walls of grape berry skin
