Effect of yeast strain on aroma compounds in Cabernet franc icewines

Ontario Cabernet franc icewine musts were fermented using four yeasts [V1116 (Saccharomyces cerevisiae), EC1118 (Saccharomyces bayanus), VL1 (S. cerevisiae), spontaneous (SPON)]. The objective was to quantify aroma compounds by GC-MS, and to compare their concentrations between yeast treatments. These compounds had odor activity values >1 across all yeasts: isoamyl alcohol, 2-methyl-1-butanol, ethyl-2-methylbutyrate, isoamyl acetate, 3-octanone, ethyl hexanoate, hexanoic acid, citronellol, 1,1,6-trimethyl-1,2-dihydronaphthalene (TDN). EC1118 and SPON had most odor-active compounds quantified (28). SPON was unique in its production of geranyl acetone and ethyl benzoate. EC1118 had highest concentrations of 15 compounds including: four alcohols, seven esters, furfural, hexanoic acid, TDN, β-damascenone. SPON produced highest: 1-hexanol, phenylethanol, citronellol, nerol, β-phenyl acetate, γ-nonalactone. VL1 had highest: linalool, cis-rose oxide, ethyl octanoate, ethyl decanoate. V1116 had highest decanal. Most esters, alcohols, and ketones were correlated based on PCA, while citronellol, geranyl acetone, 1-hexanol, and 3-octanone were negatively correlated with most others. EC1118, V116, and VL1 wines were well-described by most esters, alcohols, aldehydes, and ketones. SPON was best described by β-phenylacetate, nerol, citronellol, geranyl acetone, 1-hexanol, and 3-octanone, suggesting different yeast species produced unique compounds or higher concentrations of specific compounds relative to other treatments.