Pinot noir has a reputation for lower color stability than other red wine varieties.
Because it has relatively low anthocyanin and phenolic content and lacks acylated
anthocyanin pigments compared to other red vinifera varieties, color extraction and
stability are particularly important. Varying the processing during fermentation of red
wine can produce high quality wines. Pectolytic enzymes are used in wine processing for
many purposes from increasing juice yield and filtering rates to improving color and
phenolic extraction.
Macerating enzymes used in this study, Scottzyme Color Pro (Scott
Laboratories), Scottzyme Color X (Scott Laboratories), Lallzyme EX (Lallemand), GB
Rapidase EX Color (Gist Brocades), and Vinozyme G (Cellulo) were added to 1997
Oregon Pinot noir must prior to fermentation to observe color, aroma and flavor changes.
These commercial enzymes have been reported to increase color and improve aroma and
flavor of red wines. The effect of these enzymes had not previously been investigated on
Oregon Pinot noir but the manufacturers reported increased polymeric phenols, polymeric
anthocyanins, tannins, color stability, red hue and saturation of red wine varieties. These
enzymes have varying manufacturer recommended usage levels and it is not known how the dosage levels and the enzymes themselves affect Oregon Pinot noir. Sensory
evaluations of these wines, at a high and low dosage level, were conducted through free-choice
profiling by winemakers and descriptive analysis from a trained panel. In addition,
chemical analyses were performed and related to sensory panel results.
Overall the addition of these enzymes to Oregon Pinot noir produced wines with greater
purple, red descriptors and higher color intensity than the control wine from trained
descriptive panel and winemaker panel results. In aroma, the enzyme treated wines were
higher in vegetative and earthy descriptors compared to the control. GB Rapidase EX
Color (Gist Brocades) was higher in bitterness flavor compared with other samples.
Low enzyme wine treatments separated wine samples more from the control then high
enzyme wine treatments. The color and appearance, aroma and flavor axes of the profile
maps were not significant in the high enzyme treated wines as determined from the
winemaker panel. Furthermore, the winemaker panel found acidity the only aroma or
flavor descriptor significant in the high dosage ANOVA results. Whereas six descriptors
in the low enzyme ANOVA results were significant in separating aroma and flavor
samples. Except for Lallzyme EX (Lallemand) treated wine, the hunter colorimeter results
showed all low enzyme treated wines were significantly (p<0.05) more red-purple (lower
hues) than the high enzyme treated wines. / Graduation date: 1999
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/27273 |
| Date | 04 December 1998 |
| Creators | Goldberg, Naomi |
| Contributors | McDaniel, Mina R. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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