Deconstructing Wine Grape Cell Walls with Enzymes During Winemaking: New Insights from Glycan Microarray Technology

Abstract

Enzyme-aid maceration is carried out in most modern winemaking industries with a range of positive impacts on wine production. However, inconsistencies in enzyme efficiency are an issue complicated by unclear targets (limited information available on berry cell wall architecture of different cultivars) and the complex wine environment (i.e., fermenting must). Recent studies have been performed to develop a clearer picture of grape cell wall structures, maceration effects, and interactions between important wine compounds and grape-derived polysaccharides. This review highlights critically important recent studies on grape berry cell wall changes during ripening, the importance of enzymes during maceration (skin contact phase) and deconstruction processes that occur during alcoholic fermentation. The novelty of the Comprehensive Microarray Polymer Profiling (CoMPP) technique using cell wall probes (e.g., antibodies) as a method for following cell wall derived polymers during different biological and biotechnological processes is discussed. Recent studies, using CoMPP together with classical analytical methods, confirmed the developmental pattern of berry cell wall changes (at the polymer level) during grape ripening. This innovative technique were also used to track enzyme-assisted depectination of grape skins during wine fermentation and determine how this influence the release of wine favourable compounds. Furthermore, polysaccharides (e.g., arabinogalactan proteins) present in the final wine could be identified. Overall, CoMPP provides a much more enriched series of datasets compared to traditional approaches. Novel insights and future studies investigating grape cell wall and polyphenol interactions, and the tailoring of enzyme cocktails for consistent, effective and “customized” winemaking is advanced and discussed.

The Influence of Hydrolytic Enzymes on Tannin Adsorption-Desorption onto Grape Cell Walls in a Wine-Like Matrix

“…These results are probably due to the unravelling effect of this enzyme on cell wall structure, exposing the hemicellulose layers to the action of ethanol. Similar results were observed by Gao et al [ 23 , 25 ] studying the cell walls of Cabernet Sauvignon grape pomace isolated after treatment with pectinases enzymes during vinification. Xyloglucan epitope signals slightly decreased when xylanase was present, indicating that, although a xyloglucan depolymerization was promoted by this enzyme, its action was quite limited, probably due to its restricted access to the hemicellulose network, since the pectic matrix had not been degraded by any pectinase [ 26 , 27 ], therefore, this enzyme could only act on those xyloglucans present in that pectic matrix, according to the proposed grape cell wall model by Gao et al [ 23 ] No change from untreated CW was observed in NaOH extract when PME and CEL enzymes were used.…”

“…Again, these results coincide with that obtained with CoMPP analyses, where a high de-pectination and de-esterification was observed with this enzyme and explained the largest effect of CEL and PEC enzymes in limiting tannin adsorption due to the decrease of pectin polymers, where tannins preferentially bind. Gao et al [ 23 , 25 ] also reported the effectiveness of a mix of polygalacturonase and pectin lyase enzymes at removing cell wall pectin-coating layers, providing easier access to the hemicellulose polymers. Furthermore, an increase in the low molecular weight polysaccharide fractions (with a molecular mass range closer to that of the RG II monomer) was found in grape cell walls treated with a polygalacturonase-rich commercial enzyme as performed by Bindon et al [ 29 ] The presence of tannins in the experiment only modified the profile of polysaccharides released, increasing those of a lower molecular weight.…”

The Potential of Grape Pomace Varieties as a Dietary Source of Pectic Substances

“…Grape skin CW consists of 30% benign polysaccharides (galactan, cellulose, xyloglucan, arabinan, xylan and mannan), 20% acidic pectic substances (63% are methyl esterified), ≈15% insoluble proanthocyanidins and less than 5% of structural proteins [ 3 , 18 , 42 , 43 , 44 , 45 ]. Three important tiers form the CW of grape berries [ 46 ]. (1) The middle lamella, which ties up the cells, is primarily made up of pectin.…”

Qualitative effects of the addition of withered grapes to a freshly produced red wine: the traditional governo all'uso toscano practice

“…Under these conditions, the solubility and solubilisation kinetics of grape compounds are completely different to that normally found in unfermented grape juice or during cold soaking. Furthermore, grape skins' cell wall and membrane permeability and/or integrity are modified at this alcohol concentration, another phenomenon that is not usually found in grape juice (Ribéreau-Gayon et al 2006, Río Segade et al 2016, Gao et al 2019. In addition, the high sugar concentration of withered grapes is diluted into a finished wine with no residual sugars, and microorganisms on berries (Salvetti et al 2016) have to compete during the second fermentation with a yeast population residual from the first alcoholic fermentation and with other microbial species eventually found in the winemaking environment.…”