• Journal of the Korean Society of Food Science and Nutrition
• /
• v.32 no.8
• /
• pp.1206-1213
• /
• 2003

In order to use nutraceutical components in Yulmoo (Coix lachryma-jobi L. var. ma-yuen Stapf), the acceptability of Yulmoo for Takju (Korean rice wine) was examined in terms of the production of volatile components. When Yulmoo was added to the Takju made by commercial koji as a substitute of starch at 0 (rice 100%), 15, 30, 60, and 100%, the ethanol content slightly increased to 13.6, 15.2, 15.2, 14.1, and 13.8%, the Production of isobutanol and iso-imyl alcohol increased as the amount of Yulmoo increased. While the use of Yulmoo to the Takju as the nuruk (Korean traditional koji), inoculated with Aspergillus kawachii (AK) and Rhizopu japonicus (RJ), decreased the contents of n-propanol, iso-butanol, and iso-amyl alcohol as well as the contents of ethanol from 14.3% to 11.2 [AK], 7.5 [RJ], and 10.4% [AK + RJ]. The Yulmoo nuruk in Takju increased the production of acetaldehyde and ethyl acetate indicating the negative effect in the organoleptic evaluation. It was determined that the addition of Yulmoo as a starch source or as nuruk has a critical effect on the production of fusel oils and other volatile compounds in Takju fermentation.

• Journal of the East Asian Society of Dietary Life
• /
• v.22 no.1
• /
• pp.103-108
• /
• 2012

Nuruk is a fermented ingredient used for production of traditional Korean rice wine. In this study, quality characteristics of mixed-grain nuruk was made by brewing with different fungal strains was analyzed. Quality elements including enzyme activity and organic acids constituents were measured. The fermentation time of the nuruk did not make a significant difference in terms of its pH, but the acidity and amino acid content for nuruk made from a mixture of two fungal strains was higher than that seen with a single fungal strain. Overall, the enzyme activity for two fungal strain nuruk was higher than that observed for single fungal strain nuruk, with ${\alpha}$-amylase and acidic protease activity in the mixed strain nuruk observed to be more than twice that of the single strain. The major organic acids observed in the manufactured nuruk were identified as acetic, citric, formic, fumaric, lactic, malic and oxalic acids. The total amount of organic acids contained in the nuruk made with the two fungal strain was (2,116.3 mg%). The fungal strains used were A. kawachii SC60 nuruk (1,608.5 mg%) and A. oryzae RIB1353 nuruk (1,146.7 mg%).

• Food Science and Preservation
• /
• v.21 no.4
• /
• pp.573-580
• /
• 2014

The enzymatic activity of Nuruk and the quality properties of Yakju were investigated according to different fungi. The fungi that were used in this study were Aspergillus kawachii KCCM 32819, Aspergillus niger KCCM 32005, Rhizopus japonicus KCCM 11604, Rhizopus oryzae KCCM 11272, Rhizopus oryzae KCCM 11273, Rhizopus oryzae KCCM 11276, and Mucor rouxii KCCM 60148. The study results are as follows. The saccharogenic power of Rhizopus oryzae KCCM 11272 Nuruk was the highest (3,647.72 SP/g) among all the samples. The ${\alpha}$-amylase production and protease activities were highest (3.76 DU and 4.7 tyrosine mg/min, respectively) in the Rhizopus japonicus KCCM 11604 Nuruk. The pH levels of the Yakju made with commercial Nuruk and Rhizopus japonicus KCCM 11604 Nuruk were 4.14 and 4.07, respectively. The total titratable acid content of the Yakju made with Rhizopus oryzae KCCM 11273 Nuruk was the highest (0.56%) among all the samples. Rhizopus japonicus KCCM 11604 and Rhizopus oryzae KCCM 11272 had the highest ethanol yields (15.18% and 15.10%, respectively). In the sensory evaluation carried out in this study, the panel preferred the Yakju made with Rhizopus japonicus KCCM 11604 Nuruk. Overall, however, the panel did not like the Yakju made with Aspergillus niger KCCM 32005 Nuruk.

• Proceedings of the Korean Society for Applied Microbiology Conference
• /
• 1979.10a
• /
• pp.243.2-243
• /
• 1979

현재 우리나라의 탁약주 용 Rice-Koji 제조 용종국균으로 널리 분양되고 있는 분양되고 있는 fawachi, S-27 균주가 생성하는 Amylase의 효소학적 특성과 Rice-Koji i제조 시 유기산 및 당화 효소의 생성 조건을 검토했다. 1. 본 균은 유기산 생성력이 강하고 또 생성하는 당화효소 및 액화효소는 내산성이 극히 강하며 pH3~5의 범위내에서 최고 활성을 나타내었으므로 탁약주 제조 용 종국균으로 아주 적합하였다. 2. 본 균의 발아 최적온도는 36$^{\circ}C$이었으며 Rice -Koji제조시 제국시간을 40시간으로 볼 때 유기산 생성의 최적온도는 32$^{\circ}C$이었고 당화효소 생성의 최적온도는 36$^{\circ}C$이었으며 고온인 4$0^{\circ}C$에서는 유기산 생성이 극히 불량하였다. 3. Rice-Kojiw제조시 당화효소의 생성은 배지의 수분함량 35%일 때 최고치를 보였으며 유기산 생성은 이 보다 높은 조건인 수분함량 40%일 때 이었고 비교적 건조한 조건인 수분함량 30%일 때는 유기산 생성이 특히 불량하였다. 4. 배지의 두께가 3cm이상이 되면 유기산 및 당화효소 생성에 않은 지장을 주었다. 5. 종국균의 점종량은 유기산 및 당화효소의 생성에 별로 영향을 미치지 못했다.

• Korean Journal of Food Science and Technology
• /
• v.22 no.6
• /
• pp.696-699
• /
• 1990

Some mixed culture systems consisting of koji molds and yeast were tested for the ethanol production by simultaneous saccharification and fermentation using polished rice as the substrate. Aspergillus shirousamii showed the highest ethanol production in the mixed culture with Saccharomyces cerevisiae on steamed rice added with 150 ml water in 250 ml Erlenmeyer flask. The optimum initial pH, temperature and specific surface for the ethanol production in this system were 6.5, $30^{\circ}C$, and 0.1, respectively. Under this condition, 12.9% ethanol was produced with inoculation with $5{\times}10^2$ conidia/ml of A. shirousamii and $5{\times}10^6\;cells/ml$ of S. cerevisiae in 10 days.

• The Korean Journal of Food And Nutrition
• /
• v.12 no.3
• /
• pp.219-225
• /
• 1999

In order to improve the quality of nuruk a Korean traditional fermenting agent for brewing nuruk was modified by a new method inoculating Rhizopus japonicus T2 Aspergillus oryzae L2 and hansenula sp. BC26 which had been isolated from traditional Nuruk. And the characteristics of modified Nuruk were investimgated as compared with current fermenting agents such as commercial Nuruk and rice koji of As-pergillus kawachii. The odor of modified Nuruk was savory but those of commercial Nuruk and rice koji were fetid andinodorous repectively. The extracted waters of modified Nuruk commercial Nuruk and rice koji were yellow pale yellow and colorless and showed 6.15, 6.01 and 3.30 of pH respectively. Mod-ified Nuruk had 7.6${\times}$106CFU/g of yeast but commercial uruk and rice koji had no yeast. Commercial Nuruk had 1.0${\times}$102CFU/g of lactic acid bacteria but modified Nuruk and rice koji had no lactic acid bacteria. The amylolytic and proteolytic activities of modified Nuruk were much higher than those of commercial Nuruk or rice koji. Seed mash of modified Nuruk had ester aroma but that of commercial Nuruk rather offensive odor and that of rice koji neither ester aroma or offensive odor. It seemed that if the modified Nuruk is used in seed mashing the supplement of acidulant is need to lower pH. The quality of modified Nuruk was thought to be much better than that of commercial Nuruk or rice koji.

• Journal of Microbiology and Biotechnology
• /
• v.23 no.7
• /
• pp.932-941
• /
• 2013

This work aimed to classify Aspergillus (8 species, 28 strains) by using a secondary metabolite profile-based chemotaxonomic classification technique. Secondary metabolites were analyzed by liquid chromatography ion-trap mass spectrometry (LC-IT-MS) and multivariate statistical analysis. Most strains were generally well separated from each section. A. lentulus was discriminated from the other seven species (A. fumigatus, A. fennelliae, A. niger, A. kawachii, A. flavus, A. oryzae, and A. sojae) with partial least-squares discriminate analysis (PLS-DA) with five discriminate metabolites, including 4,6-dihydroxymellein, fumigatin, 5,8-dihydroxy-9-octadecenoic acid, cyclopiazonic acid, and neosartorin. Among them, neosartorin was identified as an A. lentulus-specific compound that showed anticancer activity, as well as antibacterial effects on Staphylococcus epidermidis. This study showed that metabolite-based chemotaxonomic classification is an effective tool for the classification of Aspergillus spp. with species-specific activity.

• The Korean Journal of Food And Nutrition
• /
• v.12 no.4
• /
• pp.421-426
• /
• 1999

The major flavor compounds of Takju mash which was brewed with a modified Nuruk made by inocu-lation and cultivation of Rhizopus japonicus T2, Aspergillus oryzae L2 and Hansenula sp. BC26 isolated from Nuruk, were analyzed, as compared with those with current fermenting agents such as commerical Nur-uk and rice koji of Aspergillus kawachii. The contents of isoamyl alcohol isobutyl alcohol and ethyl acet-ate which were known as aroma compounds in Takju were much higher in mash of modified Nuruk than in that of commercial Nuruk or ricd koji. The major organic acids were lactic fumalic and succinic acid in mash of modified and lactic and acetic acid in mash of commercial Nuruk and citric lactic and suc-cinic acid in mash of rice koji. The contents of total organic acids were 5,146mg/L, 1,706mg/L and 1, 388 mg/L in mash of commercial Nuruk rice koji and modified Nuruk respectively. The major free amino acids were glutamic acid alanine proline and histidine in mash of modified Nuruk and glutamic acid proline leucine and histidine in mash of commercial Nuruk and arginine proline and glutamic acid in mash of rice koji. The contents of total free amino acids were 14,090mg/L 12,202mg/L and 7,152 mg/L in mash of modified Nuruk commercial Nurcuk and rice koji respectively. Therefore it seemed that the Takju mash of modified Nuruk was better than that of commercial Nuruk or rice koji.

• The Korean Journal of Food And Nutrition
• /
• v.12 no.4
• /
• pp.427-432
• /
• 1999

Physicochemical and sensory properties of Takju which was brewed with a modified Nuruk made by inoculation and cultivation of Rhizopus japonicus T2. Aspergillus oryzae L2. and Hansenula sp. BC26 isolated from Nuruk were investigated as compared with those with current fermenting agents such as com-mercial Nuruk and rice koji of Aspergillus kawachii. The contents of total acid were 0.88% 0.47% and 0.39% in mash of commercial Nuruk rice koji and modified Nuruk respectively. The contents of alcohol were 15.5% 15.1% and 9.0% in mash of modified Nuruk rice koji and commercial Nuruk respectively. The contents of reducing sugar were 2.80% 1.24% and 0.80% in mash of commercial Nuruk modified Nuruk and rice koji respectively. The contents of amino acid were 0.55% 0.47% and 0.23% in mash of modified Nuruk commercial Nuruk and rice koji respectively. Suspended solids were sedimented much more slowly in Takju of modified Nuruk or commercial Nuruk than in that of rice koji Color was pre-ferred in the order of Takju of modified Nuruk commercial Nuruk and rice koji. Odor and taste were preferred in the order of Takju of modified Nuruk rice koji and commercial Nuruk. Therefore it seem-ed that the Takju of modified Nuruk was better than that of commercial Nuruk or rice koji in quality.

• Culinary science and hospitality research
• /
• v.23 no.1
• /
• pp.95-102
• /
• 2017

This study was activity of ${\alpha}-amylase$, glucoamylase of liquid Nuruk prepared using liquid Nuruk (NK) and Aspergillus kawachii (AK), Aspergillus niger (AN), Aspergillus oryzae (AO), Monascus kaoliang (MK). To investigate the relationship between the enzymatic activity and the total sugar content of liquid Nuruk depending on the types of Nuruk molds and the degree of rice-polishing. The activity of ${\alpha}-amylase$ depending on the types of Nuruk molds was shown to be 8.82, 8.72 units/mL in AN and AK treatments in brown rice liquid Nuruk at 24 hours after incubation, as the degree of rice-polishing increased, the activity of ${\alpha}-amylase$ was significantly lower (p<0.05). When brown rice was incubated in AN, it showed 8.83 units/mL at 48 hours after incubation, which was the highest activity, but there was no significantly difference (p<0.05), as the degree of rice- polishing was higher, the activity of ${\alpha}-amylase$ was lower. The activity of glucoamylase depending on the degree of rice-polishing showed 3,013 units/mL in AO treatment in brown rice liquid Nuruk at 24 hours after incubation, and the enzymatic activity was significantly higher (p<0.05). As the degree of rice-polishing increased, the activity of glucoamylase decreased, so liquid brown rice Nuruk showed the highest enzymatic activity, liquid white rice Nuruk was the lowest enzymatic activity. The highest enzymatic activity appeared in liquid Nuruk with brown rice at 48 hours after incubation. The activity of ${\alpha}-amylase$, glucoamylase showed higher enzymatic productivity as the degree of rice-polishing was lower, and there was an inverse correlation with the total sugar content.