Effect of intra‐vineyard ripeness variation on the efficiency of commercial enzymes on berry cell wall deconstruction under winemaking conditions
Abstract
Intra-vineyard variation grape berry ripening occurs within bunches, between bunches on the same vine and between vines. Although it is assumed that such variation also occurs at the grape berry cell wall level, no study to data has investigated in any depth. Here we have used a intra-vineyard panel design to investigate pooled bunches from six vines (per panel) in the context of a winemaking scenario. The dissected vineyard was harvested by separate panels, where each panel was then subjected to a standard winemaking procedure with or without the addition of three different enzyme preparations for maceration. Adjacent untreated panels acted as the enzyme controls. Hence we combined two studies into one design. Cell wall material harvested from the treated and untreated panels were subjected to high throughput cell wall profiling tools combined with multivariate data analysis. The study showed that significant variation at the cell wall polymer level occurred across the vineyard amongst the different panels. Furthemore, all enzyme applications had a strong and clear effect in reducing this variation through de-pectination. What was most interesting is that while de-pectination occurred the levels of esterification were unaffected by the enzymes. This is a positive for wine quality as no methanol or acetates would have been produced from the de-pectination and not all natural grape berry variation is affected. This study provides clear evidence that enzymes can positively influence the consistency of winemaking without necessarily removing all variability provided from the vineyard. This study provides a foundation for further research into the relationship with grape berry cell wall architecture and enzyme formulations.
Issue: Macrowine 2016
Type: Poster
Authors
*Institute for Wine Biotechnology