• 한국식생활문화학회지
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• 제11권5호
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• pp.711-719
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• 1996

Fermentation characteristics of kwahaju (a typical Korean traditional alcoholic beverage) base were investigated during fermentation with different contents of nuruk (Korean-style bran koji) extract. The nuruk extract which was prepared by incubating the mixture of nuruk powder and water at $25^{\circ}C$ overnight and by filtering it was used to be 0.6%, 2.7%, 5% and 10% (v/v). Total and reducing sugar contents as well as acidity of the kwahaju base with 0.6% nuruk extract were higher than those with 2.7%, 5% and 10% at the fermentation end. Final pH values of all the base samples were ranged from 3.3 to 4.1. Alcohol concentrations of the base samples with 2.7%, 5% and 10% nuruk extract were higher than those with 0.6%. Microbial growth rate was great and inner temperature was high in the sample with high content of nuruk extract, but fermentation period was short. Total sugar consumption and alcohol production increased as the content of nuruk extract increased, but total acid production decreased. The base sample with 10% nuruk extract showed the most excellent fermentation efficiency. Fusel oil content of the base sample with 2.7% nuruk extract was the highest (457.3 ppm), and those wity 5% and 10% nuruk extract were 438.9 ppm and 442.6 ppm, respectively. The sample with 0.6% nuruk extract had the lowest content (409.5 ppm). Sensory evaluation of both the kwahaju base and kwahaju mix with 25% and 40% alcohol by adding soju (Korean distilled liquor) showed that the base with 2.7% nuruk extract had the highest score, and that the kwahaju mix with 25% alcohol had higher score than that with 40%. The sensory results on overall desirability were consistent to those on color and alcohol concentration, and it turned out that the two factors were important to make kwahaju.

• 한국식품과학회지
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• 제48권3호
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• pp.223-230
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• 2016

본 연구에서는 약주의 이취와 갈변 원인물질을 알아보기 위해 제균한 누룩추출물을 첨가하여 약주를 제조하고 특성을 확인하였다. 알코올 함량은 재래누룩에서 16.33%, 개량누룩에서 18.67%로 개량누룩에서 1.1배 높게 나타났다. 산도(mL/10 mL)는 재래누룩 5.07, 개량누룩 8.32, 아미노산도 함량(mL/10 mL)도 각각 1.61, 4.72로 개량누룩이 약 2.9배 증가하였다. 당화력에 크게 영향을 미치는 글루코아밀레이스는 재래누룩에 비해 개량누룩이 3.2-44.0배 높은 활성을 보였고, 가용 고형물(r =0.965)과 색차(r =0.954)와 매우 높은 상관성을 보였다. 유기산은 숙신산과 젖산 함량이 가장 높게 나타났으며, 유리 질소화합물 함량(mg/L)은 재래누룩 540.0, 개량누룩 2285.9로 개량누룩에서 4.2배 높게 나타났다. 각 누룩추출물 약주의 이취 및 갈변은 유리질소화합물(r =0.539, 0.792)과 높은 상관성을 보였다.

• Journal of Microbiology and Biotechnology
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• 제18권8호
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• pp.1423-1426
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• 2008

Nuruk, which is a natural inoculator and source of amylolytic enzymes, is used in Korean traditional rice wine. A methanol extract of nuruk (NE) attenuated lipopolysaccharide (LPS)-induced nitrite and interleukin (IL)-6 in RAW 264.7 cells. Both the n-hexane and water fractions from NE (MEH and MW, respectively) inhibited the production of nitrite and IL-6 in RAW 264.7 cells. MEH and MW also inhibited the LPS-induced inducible nitric oxide synthase expression. Further, and MEH protected against the LPS-induced activation of p38 mitogen-activated protein kinase. Together, these results indicate that nuruk may contribute to the anti-inflammatory and cancer-preventive effects of Korean traditional rice wine.

• 한국식품영양학회지
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• 제36권5호
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• pp.341-353
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• 2023

In this study, we aimed to develop a fermented green rice beverage with a unique flavor and physiological function activity. With glutinous green rice and rice nuruk as independent variables, we modeled the antioxidant characteristics and α-glucosidase, α-amylase inhibitory activity of glutinous green rice fermented beverage to verify its significance. The total flavonoid content and α-glucosidase inhibitory activity were selected as Quadratic models, and DPPH radical scavenging ability and α-amylase inhibitory activity were selected as linear models. For the sensory characteristics of glutinous green rice fermented beverage, sweetness, sourness, savory taste, bitterness, throat feel, nuruk scent, and overall preference increased in preference as the amount of glutinous green rice and rice nuruk increased, but significantly decreased after the center point (p<0.01). A blending ratio of 180.00 g of glutinous green rice and 400.00 g of rice nuruk had the highest preference among all the sensory items. Based on these results, we developed a green rice fermented beverage with unique flavor and physiological function activity of rice using glutinous green rice and rice nuruk, and the optimal blending ratio was determined to be 164.04 g of white rice, 195.96 g of glutinous green rice, and 414.61 g of rice nuruk.

• Journal of Biomedical and Translational Research
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• 제19권4호
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• pp.103-109
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• 2018

Aspergillus luchuensis 34-1 was inoculated into wheat pellets with different conditions of raw materials to produce nuruk. The degree of substrate reactivity improvement of steam treated raw materials compared with that of non-heat treated was analyzed. The water content of the pellet was adjusted to 25% and 35%, and steam treatment for 10 minutes improved the substrate reactivity at 2.1-fold and 3.1-fold, and sterilization was also possible. The characteristics of improvement pellet nuruk were investigated according to the degree of crushing and water content of raw materials according to the temperatures and humidities ($23^{\circ}C$, $30^{\circ}C$ and RH 60%, RH 80%). The pH of the pellet nuruk was higher depending on the temperature, humidity and moisture content of the koji were lower, and the pH of the flour-pellet nuruk was lower than that of 2 mm milling wheat-pellet nuruk according to milling degree. It can be seen that the milling degree affects the growth of mold. The acidity and amino acid were generally higher as fermentation time increased. Also, the higher the incubation temperature, humidity and moisture content, the higher the value. Glucoamylase activity was significantly the highest in moisture content 35% D2b nuruk, cultured at $30^{\circ}C$ and 80% RH for 38 hours. This is higher than the previous reports on glucoamylase of rice-koji or commercial nuruk using fungi isolated from traditional nuruk. From these study, it is expected that making of improvement pellet nuruk would save the fermentation time considerably compared with traditional nuruks.

• 한국미생물·생명공학회지
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• 제27권3호
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• pp.236-245
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• 1999

Andong Soju is a Korean traditional distilled liquor brewed with Nuruk which is cultured with wild microorganisms. To provide useful information for scientific production and systematic quality control of traditional distilled liquor, the effects of mixed culture of the alcoholic yeasts and saccharifying molds isolated from the Nuruk, and mashes on the flavor and sensory characteristics were investigated. Distillate from mashes cocultured with Saccharomyces cerevisiae and Hansenula anomala using Mucor Nuruk was compared with distillate from mashes brewed with Andong Nuruk and with distillate from plant fermented mashes to analyze their flavor characteristics. The volatile flavor compounds in distillates were analyzed by GC and GC-MS using direct injection, solvent extraction, and purge & trap methods. Alcohols such as 3-methyl-1-butanol, 2-methyl-1-propanol, 1-propanol, and 2-phenyl ethanol; aldehydes such as acetaldehyde and 2-furancar-boxaldehyde; esters such as ethyl ester of acetic acid, hexanoic acid, octanoic acid, decanoic acid; alkanes, alkenes, ketone, sulfur, and pyrone compounds were detected. Alcohols were chief components of flavor compounds. No significant difference in overall acceptability test was shown among three experimental groups(p<0.05), but Nuruk-like aroma, Kaoliangchiew-like aroma, sweet taste, and well rounded mouthfeel showed significant differences among them(p<0.05).

• 한국미생물·생명공학회지
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• 제23권6호
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• pp.737-746
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• 1995

Through the study of identification of filamentous molds isolated from 12 traditional Nuruk, collected from several regions in Korea, 78 strains of Absidia spp., including Absidia corymbifera, Absidia ramosa, and Absidia sp. of which specific names were not identified, 19 strains of Rhizopus spp. including Rhizopus cohnii, Rhizopus arrhizus, and Rhizopus oryzae, 8 strains of Circinella spp., 1 strain of Actinomucor sp., 49 strains of Aspergillus spp., including Aspergillus oryzae, Aspergillus flavus, Aspergillus flavus var. columnaris, Aspergillus wentii, Aspergillus candidus, Aspergillus fumigatus, Aspergillus niger, and Aspergillus foetidus, 2 strains of Cladospoyium spp. and 2 strains Botryotrichum spp., etc. total 159 kinds of filamentous molds were isolated and identified. There were many differences in numbers and distributions of filamentous molds from each Nuruk according to their collected region. Absidia spp. were most frequently isolated from every Nuruk sample. Aspergillus oryzae, Aspergillus candidus, and Rhizopus cohnii showed even distribution. Penicillium sp. and Mucor sp. were not detected. Actinomucor sp., Aspergillus foetidus, Botryotrichum sp., and Cladosporium spp., which have not been reported by far, were found. Amylase activities, pH stability of amylase, and acid productivity of isolated strains were compared.

• 한국식품영양과학회지
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• 제42권12호
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• pp.2042-2048
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• 2013

본 연구에서는 상황버섯을 활용한 발효주 및 증류주를 전통누룩과 개량누룩을 사용하여 제조하고 품질 특성을 알아보았다. 술덧의 알코올 함량은 개량누룩보다 전통누룩으로 발효에서 더 높았으며, 상황버섯의 첨가량이 증가할수록 알코올 함량도 증가하였다. 술덧의 pH는 발효가 진행될수록 감소하였으며, 전통누룩과 개량누룩 간에 유의차는 없었다. 총 산 함량은 전통누룩 발효에 비하여 개량누룩 발효에서 더 낮았으며, 상황버섯 첨가군이 대조군보다 낮았다. 증류주의 향기성분 중 i-amyl alcohol이 주된 퓨젤유였으며, 전통누룩 발효에서보다 개량누룩 발효에서 더 높은 함량을 나타내었다. i-butanol 함량은 전통누룩 발효에서보다 개량누룩 발효에서 더 높았다. 에스테르 화합물 중 ethyl acetate가 가장 높은 함량을 나타내었으며, 전통누룩 발효에서 상황버섯의 첨가량이 증가할수록 ethyl acetate 함량이 유의적으로 증가하였다.

• 동아시아식생활학회지
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• 제25권6호
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• pp.1041-1048
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• 2015

This study was performed to produce quality vinegar using different types of nuruk, which is the most effective in making traditional brown rice vinegar. The vinegar was produced with 20% vinegar starter, and pears were added to reduce the nuruk aroma. Three different types of Nuruk that were prepared were rice, wheat, and a rice+wheat (1:1) combination. The total acidities of brown rice pear vinegar made from rice-nuruk, wheat-nunuk, and rice+wheat-nuruk were 8.1%, 7.5%, and 6.4%, respectively. Free sugars, including glucose, galactose, and fructose, were highly detected from all three vinegar samples. Acetic acid and lactic acid were the major organic acids in all three vinegar samples. For free amino acids, alanine, glutamic acid, and arginine were mainly detected in all three vinegar samples. Total phenolic compounds were higher in brown rice pear vinegar made of rice-nuruk than in that made of wheat-nuruk, whereas total flavonoids showed the opposite pattern. DPPH-radical scavenging activity was higher in brown rice pear vinegar made of wheat-nuruk than in that made of rice-nuruk.

• 한국식품영양과학회지
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• 제26권5호
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• pp.767-774
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• 1997

For the standardization and quality improvement of traditional Korean Nuruk, 120 strains of fungi were isolated from Nuruks and 18 strains of them were selected as strains analysing the amylase and flavor. The genera of these fungi were identified as Aspergillus sp. (14 strains), Penicillium sp. (3 strains) and Rhizopus sp. (1 strains) by the conventional slide culture. Most of these fungi showed a better productivity of the saccharogenic and dextrinogenic enzymes in raw wheat bran culture than in cooked wheat bran culture. The ability of acid and flavor production was good in the raw wheat bran culture, and aflatoxins were not produced under the same culture. Penicillium sp. and Rhizopus sp. had high cell growth and amylast activity. Mixed culture of Aspergillus sp. No.3-6 and Penicillium sp. No.7-7 revealed a high liquefying and saccharifying activity as well as high flavors production. These results indicated that these fungi was proper strains for making Nuruk of good quality.