Volatile Flavor Components in Mash of Takju Prepared by Using Different Nuruks

누룩 종류를 달리하여 담금한 탁주 술덧의 휘발성 향기성분

Volatile flavor components in the mash of takjus prepared by using different nuruks such as Mucor racemosus nuruk, Rhizopus japonicus nuruk, Aspergillus oryzae nuruk, Aspergillus kawachii nuruk and nuruk (Korean-style bran koji), were identified by using GC and GC-MS. Twenty alcohols, 26 esters, 10 acids, 10 aldehydes and 6 others were found in the mash of takju after 16 days of fermentation. Takju by Aspergillus oryzae nuruk had the most various components of volatile flavor. Fifty-four flavor components including ethanol, 2-methyl-1-propanol, 3-methyl-1-butanol, 1-hexanol, 2,3-butadienol (D,L), benzeneethanol, acetic acid ethyl ester, succinic acid diethyl ester, butanoic acid monoethyl ester, acetic acid and benzene acetic acid 4-acetyloxy-3-methyl ethyl ester were usually detected in all the treatments. The relative peak area of volatile components was as follows: alcohol $(71.28{\sim}90.23%)$, ester $(0.66{\sim}9.05%)$, acid $(0.2{\sim}0.6%)$ and aldehyde $(0.02{\sim}0.09%)$. Specially, 1-pentanol and hexanoic acid ethyl ester were high in takju made of nuruk (Korean-style bran koji). 1-Hexanol, 1-dodecanol, acetic acid and 1,2-benzene-dicarboxylic acid diprophenyl ester were high in takju made of Mucor racemosus nuruk. 4-Acetyloxy, 3-methyl benzeneacetic acid phenyl ester, 2-methyl-1-propanol, 3-methyl-1-butanol, succinic acid diethylester, butanoic acid monoethyl ester and butanoic acid were higher content in takju by Rhizopus japonicus nuruk. Acetic acid ethyl ester, pentanoic acid and 3-methyl butanoic acid were high in takju that was made of Aspergillus oryzae nuruk. 1-Butanol was high in takju by Aspergillus kawachii nuruk.

GC와 GC-MS를 사용하여 발효 16일 후 탁주술덧의 휘발성 향기성분으로 alcohol 20종, ester 26종, acid 10종, aldehyde 10종, 기타 6종 등 모두 72종이 검출되었다. Aspergillus oryzae구는 68종으로 가장 많았고 재래누룩구의 술덧은 60종으로 적었다. 72종의 휘발성 향기성분 중 54종의 향기성분이 모든 시험 구에서 공통으로 검출되었다. 휘발성 향기성분의 면적비율은 alcohol류 $71.28{\sim}90.23%$, ester류 $0.66{\sim}9.05%$, acid류 $0.20{\sim}0.60%$, aldehyde류 $0.02{\sim}0.09%$순으로 나타났다. 시험구에 따라 차이가 있으나 ethanol, 2-methyl-1-propanol, 3-methyl-1-butanol, 1-hexanol, 2.3-butadienol(D,L), benzeneethanol, acetic acid ethyl ester, succinic acid diethyl ester, butanoic acid monoethyl ester, acetic acid 그리고 benzene acetic acid 4-acetyloxy-3-methyl ethyl ester 등의 면적 비율이 높아 본 실험 탁주 술덧의 휘발성 향기 주성분으로 나타났다. 재래 누룩구는 1-pentanol, hexanoic acid ethyl ester의 면적비율이 다른 시험구보다 높았고, Mucor racemosus 누룩구는 1-hexanol, 1-dodecanol, 1,2-benzenedicarboxylic acid dipropenyl ester, acetic acid가, Rhizopus japonicus 누룩구는 2-methyl-1-propanol, 3-methyl-1-butanol, benzeneethanol, succinic acid diethyl ester, butanoic acid monoethyl ester, 4-methyl benzeneacetic acid phenyl ester, butanoic acid의 면적 비율이 타 시험구보다 각각 높았다. Aspergillus oryzae구는 acetic acid ethyl ester, 3-methyl butanoic acid, pentanoic acid가 높았으며 Aspergillus kawachii구에서는 1-butanol이 높았다.