RT Journal Article
SR Electronic
T1 Impact of Yeast Present during Prefermentation Cold Maceration of Pinot noir Grapes on Wine Volatile Aromas
JF American Journal of Enology and Viticulture
JO Am J Enol Vitic.
FD American Society for Enology and Viticulture
SP ajev.2016.16046
DO 10.5344/ajev.2016.16046
A1 Harper Hall
A1 Qin Zhou
A1 Michael C. Qian
A1 James P. Osborne
YR 2016
UL http://www.ajevonline.org/content/early/2016/09/20/ajev.2016.16046.abstract
AB Yeasts isolated from a pre-fermentation cold maceration (8-9 °C) of Vitis vinifera L. cv. Pinot noir grapes were evaluated for β-glucosidase activity. Among the thirteen distinct yeast isolates investigated, five yeasts had β-glucosidase activity. Sequence analysis of the D1/D2 domain of the 26S rDNA gene confirmed the identity of these yeasts as Metschnikowia pulcherrima, Hanseniaspora uvarum, Lachancea thermotolerans, and two isolates of Saccharomyces cerevisiae. The β-glucosidase activity of these yeast was further investigated at different sugar concentrations and temperatures before being used in the production of Pinot noir wines. Pinot noir grapes sterilized by high hydrostatic pressure were inoculated with individual yeast species or a mixture of all yeast species and a seven day pre-fermentation cold maceration (9°C) was performed followed by alcoholic fermentation conducted by Saccharomyces cerevisiae RC212 at 27°C. Pinot noir grapes were also cold macerated without the addition of any yeast while fermentations were also undertaken with no cold maceration. Solid-phase microextraction-GC-MS analysis of the wines demonstrated that the presence of the different yeast species during the pre-fermentation cold maceration altered the volatile aroma composition of the wines. The yeasts in pre-fermentation cold soak maceration, altered the concentrations of ethyl esters, branch-chained esters, higher alcohols and some monoterpenes in the wines.