Microwave maceration of Pinot noir grape must: sanitation and extraction effects and wine phenolics outcomes
Carew, AL and Sparrow, AM and Curtin, CD and Close, DC and Dambergs, RG, Microwave maceration of Pinot noir grape must: sanitation and extraction effects and wine phenolics outcomes, Food and Bioprocess Technology, 7, (4) pp. 954-963. ISSN 1935-5130 (2014) [Refereed Article]
Pinot noir grapes have a unique phenolic profile
which can impinge on the extraction and stabilisation of
compounds such as anthocyanins and tannins which contribute
to the colour and mouthfeel of red wine. This study
examined the concentration of phenolic compounds in Pinot
noir grape must and wine following application of a novel
microwave maceration treatment for red grape must.
Microwave maceration was shown to be highly effective
for extraction of phenolics from grape solids into grape
juice. When juices were fermented to wine, ultraviolet–visible spectrophotometry showed microwave maceration
was associated with significantly higher concentrations of
total phenolics, anthocyanin, tannin and pigmented tannin in
wine at 18 months bottle age, compared with control wine.
Mean tannin concentration in microwave treatment wine
was 0.60 gm/L at 18 months, compared with 0.14 gm/L in control wine. The microwave treatment was also associated
with a substantial and rapid decrease in the grape-associated
yeast population, compared with control maceration, and a
shorter lag phase at the outset of alcoholic fermentation.
Based on this study, microwave maceration warrants further
investigation as a potential industrial-scale application in red