Influence of yeast strains on the physicochemical characteristics, methanol and acetaldehyde profiles and volatile compounds for Korean rice distilled spirit

The objective of this study was to investigate the influence of yeast strains on the physicochemical characteristics, methanol and acetaldehyde profiles, and volatile compounds of Korean rice distilled spirits. Ten yeast strains were employed for the brewing of distilled spirits and the resulting products were filtered and distilled twice. The amounts of methanol and acetaldehyde for the ten yeasts showed different profiles. Higher amounts of methanol were detected for strains CL, CY, DV, BD, ED and LP, while EC, D2, D4 and RH had <2 mg L-1 methanol content. Strains D2, BD and ED produced the lowest amounts of acetaldehyde. The head portions of the spirits, which started in the fraction that contained <5 mg L-1 of acetaldehyde, were between 7.7% (BD) and 18.2% (LP) of the total fractions. Strains D2, CL and CY produced more alcohol in the body fraction than the other yeasts. The major volatile compounds were esters in the form of fatty acid ethyl esters, such as ethyl palmitate, ethyl myristate and ethyl oleate. Isoamyl alcohol, which is an important volatile compound for rice wine, occupied 0.91-2.24% of the relative peak areas. Strain D2, of the strains tested, appeared to be the most appropriate yeast for Korean distilled spirit based on alcohol production and the high relative peak area of volatile compounds, except for ethanol. Strains CL and CY could also be considered for producing high-quality Korean rice distilled spirits with efficiency and flavour. Copyright (c) 2015 The Institute of Brewing & Distilling