TITLE:
Isolation of aromatic yeasts(non-Saccharomyces cerevisiae) from Korean traditional nuruks and identification of fermentation characteristics
AUTHORS:
Choi Ji Ho, Soo Hwan Yeo, Ji-Hye Park, Han Seok Choi, Ji-Eun Gang, Soo In Kim, Seok Tae Jeong, So Ra Kim
KEYWORDS:
Aromatic Yeast; Pichia sp.; Yakju; Korean Traditional Alcoholic Beverage; Ethyl Caproate
JOURNAL NAME:
Agricultural Sciences,
Vol.4 No.5B,
July
16,
2013
ABSTRACT:
Ethyl caproate and
isoamyl alcohol are important for the quality of Yakju, one of the Korean traditional alcoholic beverages. From
Korean traditional fermentation agent, Nuruk,
we have isolated 8 yeasts which produced rich aromatic compounds using YEPD
agar plates (1% yeast extract, 2% peptone, 2% dextrose, 2% agar) containing 50
uL cerulenin at 30℃. The isolated aromatic yeasts are
identified as Pichia anomala (4
strains), Pichia fabianii (2
strains), Pichia farinose (1
strains), Geotrichum candidum (1
strains). We conducted alcohol fermentation with each of the aromatic yeasts
and the compounds (ethyl caproate and isoamyl alcohol) producing range were
59.5 - 193.2 ppm and 10.8 - 91.6 ppm respectively. As a control, Fermivin®,
famous aromatic wine yeast, was 89.4 ppm and 16.2 ppm respectively. We also
find that the isolated Pichia anomala could produce higher level ethanol (4.2% - 5.0%, v/v) than other species (0.4%
- 2.2%, v/v). Using the aromatic yeasts in fermentation industries, we expect
to improve the quality of traditional alcoholic beverages.