• 미생물학회지
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• 제8권2호
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• pp.53-64
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• 1970

In order to study ecology of microorganisms during Takju brewing, microflora changes were examined fromm the start to the sixth day of Takju fermentation in 24 hours intervals. Takju made from rice, flour and dried sweet potato in a liter volume open container at the laboratory and a sanple of Takju brewing factory were studied for their microflora and their changes during fermentationl together with a sample of Kokja. Results obtained were as follows ; 1. The followings were the identified microorganisms in Kokja. The molds ; Absidia spinosa, Aspergillus parasiticus. The yeasts ; Candida melinii, Candida Solani, Hansenula anomala. The bacteria ; Luctobacillus casei, Leuconostoc mesenteroides, Bacillus subtilis, Bacillus pumilus. 2. Torulopsis inconspicua, Lactobacillus casei, Leuconotoc mesenteroides, Bacillus subtilis, Bacillus pumilus were isolated from main mash of laboratory-made Takju samples. The yeast, Torupsis inconspicua which was not present in Kokja and, probably of a contaminant yeast, dominated the yeast flora of Takju mash of rice, flour and sweet potato of labotatory brewing. The laboratory brewing lost also always showed large population of lactic acid bacteria flora. 3. None of the wild yeasts which were present in Kokja appeared in Takju mashes. The Kokja appears to be of no use as the yeast source for Takju fermentation. Also the Kokja appears to be of not so effective amylolytic and proteolytic enzyme sources considering the microflora characteristics. Probably the major role of Kokja in Takju fermentation may be to contribute in taste formation. 4. Inoculation of Sacharomyces cerevisiae into the mash to the level of $10^7$ ml at the start of fermentation greatly changed the ecological aspects eliminating conditions of rather slow rising of natural contaminant yeast populaiton and fermentation which might give rise to prosperity of lactic acid and Bacillus bacteria that would be avoidable. 5. Examination of microflora of the large factory scale Takju fermentation showed the quite similar pattern of microflora and their changes to that of the cultured yeast-inoculated laboratory batch Takju fermentation. The cultured yeast dominated as the only predominant microflora, and the lactic acid bacteria flora were completely suppressed and aerobic bacteria, greatly. Probably this may be the regular microflora pattern of normal Takju fermentation. The role of lactic acid bacteria and aerobic bacteria in Takju fermentation may not be clear yet from this experiment alone.

• 한국산학기술학회논문지
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• 제16권8호
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• pp.5468-5475
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• 2015

본 연구는 가수량을 달리하여 제조된 전통방식의 청주의 발효 및 숙성 특성 변화를 분석하는데 있다. 실험방법으로는 발효 술덧은 3단 담금 하였고 3단 담금시 물을 넣지 않은 청주(A), 1L의 물을 가수한 청주(B), 2L의 물을 가수한 청주(C) 등 3종류의 청주 비교 실험을 진행하였다. 물을 첨가한 청주(B)과 청주(C)가 물을 첨가하지 않은 청주(A)보다 당도, 비중, 산도 및 pH 변화를 분석한 결과 전체적으로 발효력이 우수한 것으로 나타났다. 청주의 숙성($5^{\circ}C$, 6개월)후 아로마 패턴을 분석한 결과, 청주의 주요 아로마 성분인 에틸아세테이트(ethyl acetate)는 가수하여 제조한 청주에서 더 많이 검출되었고 숙성기간동안 그 패턴은 계속 유지되었다. 고급알코올(n-propanol, i-butanol, n-butanol, i-amyl alcohol, n-amyl alcohol)도 가수량이 증가할수록 유의적으로 증가하였고 숙성기간중에 그 패턴을 유지하였다. 유기산 성분은 청주(A)에서 4661.47 mg/L, 청주(B)에서 4873.46 mg/L 그리고 청주(C)에서 4963.12 mg/L 검출되어 가수량이 증가할수록 총산은 증가하였다. 결론적으로 2단 담금에서 물을 첨가하여 제조한 청주가 물을 첨가하지 않은 청주에 비해 우수한 발효력과 품질 및 증가된 아로마를 나타냈으며 물을 첨가한 샘플사이에서는 유의적 차이가 없는 것으로 나타났다.

• 한국식품영양학회지
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• 제12권3호
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• pp.226-232
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• 1999

To evaluate the characteristics of modified nuruk made by inoculation and cultivation of Rhizopus jap-onicus T2, Aspergillus oryzae L2 and hansenula sp. BC26 three different Takju mashes were made with modified Nuruk commercial Nuruk and rice koji and the changes in microorganisms and major compon-ents of mashes were investigated uring brewing. The numbers of yeast kept higher in the mash of mod-ified Nuruk or rice koji. The numbers of lactic acid bacteria were high in mash of commercial Nuruk but those were not in mash of modified Nuruk or rice koji. all mashes showed stable pH in a day and the pH kept higher in mash of modified Nuruk than in that of commer-cial Nuruk or rice koji. Increase in the content of total acid was moderate in mash of modified Nuruk or rice koji but it was too much in that of commercial Nuruk. increase in the content of amino acid was much highr in mash of modified Nuruk or commercial Nuruk than in that of rice koji. Increase in the content of alcohol was more rapid in mash of modified nuruk or rice koji than in that of commercial Nur-uk. The content of reducing sugar kept highter in mash of commercial Nuruk or modified Nuruk than in that of rice koji. A small amount of modified Nuruk accomplished favorable fermentation showing nor-mal patterns in microbiological and physicochemical changes during brewing.

• Journal of Microbiology and Biotechnology
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• 제29권6호
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• pp.877-886
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• 2019

Brewing with buckwheat as an ingredient has been proven to be successful in several previous studies. However, few studies have focused on the effects of buckwheat on the rutin content and antioxidant activity of beer. In order to develop a lager beer with high rutin content and desirable sensory characteristics, tartary buckwheat malt was used as a brewing adjunct. The results showed that the rutin-degrading enzyme was the key factor affecting the rutin content in the wort and beer. Compared to beer made using the common mashing method, the rutin content in the buckwheat beers produced using an improved mashing method was approximately 60 times higher. The total flavonoid contents in buckwheat beers also depended strongly on the mashing methods, ranging from 530.75 to 1,704.68 mg QE/l. The rutin-rich beers also showed better oxidative stability during forced-aging. Meanwhile, the buckwheat beers were found to be acceptable in terms of the main quality attributes, flavor, and taste.

• 한국미생물·생명공학회지
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• 제50권3호
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• pp.404-413
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• 2022

The process of manufacturing craft beer involves a wide variety of spontaneous microorganisms, acting in different stages of the brewing process, that contribute to the distinctive characteristics of each style. The objective of this work was to compare the structure of microbial communities associated with two different craft beer styles (Doppelbock and Märzen lagers), at a late maturation stage, and to identify discriminative, or style-specific taxa. Bacterial and fungal microbial communities were analyzed by Illumina sequencing of 16S rRNA gene of prokaryotes and the ITS 2 spacer of fungi (eukaryotes). Fungal communities in maturating beer were dominated by the yeast Dekkera, and by lactic acid (Lactobacillus and Pediococcus) and acetic acid (Acetobacter) bacteria. The Doppelbock barrels presented more rich and diverse fungal communities. The Märzen barrels were more variable in terms of structure and composition of fungal and bacterial communities, with occurrence of exclusive taxa of fungi (Aspergillus sp.) and bacteria (L. kimchicus). Minority bacterial taxa, differently represented in the microbiome of each barrel, may underlie the variability between barrels and ultimately, the distinctive traits of each style. The composition of the microbial communities indicates that in addition to differences related to upstream stages of the brewing process, the contact with the wood barrels may contribute to the definition of style-specific microbiological traits.

• 한국식품과학회지
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• 제29권5호
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• pp.895-900
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• 1997

식품첨가물의 일종인 cyclodextrin (CD)을 막걸리 저장중에 일어나는 이상 풍미(stinking odor)를 제거하기 위해 첨가하였다. CD는 탁주제조 후 제성직 후와 이단 담금시로 구분하여 $0.1{\sim}0.3%$ 범위에서 첨가하고 일정기간이 지난 뒤 각 시료의 발효상태와 저장성, 관능성 등을 검토하였다. 그 결과 CD를 제성한 후 첨가 하는 것보다 이단담금시에 첨가하는 것이 알코올 농도, pH, 총산, 당도에 더 많은 영향을 주었고 제성한 후에 첨가한 것은 큰 영향을 주지 못한 것으로 나타났다. 관능적인 면에서는 제성 후에 CD를 첨가하는 것이 선호도가 높게 나타났다. 그러나 CD를 많이 첨가한 경우(0.3%)에는 CD가 막걸리 자체의 고유향까지 은폐시켜 선호도를 저하시키는 것으로 나타났다.

• 한국식품과학회지
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• 제27권4호
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• pp.516-519
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• 1995

국내에서 생산된 쌀 6품종의 맥주제조특성을 국내 및 미국의 맥주회사에서 사용되는 쌀과 비교해 볼 때 국내 쌀의 수분함량은 $11.4{\sim}12.6%$로 미국 맥주회사에서 사용되는 쌀의 수분함량 10.7%보다 높았다. 장립종(long grain)이며 Indica품종인 IR36은 전분량이 적으나 단백질 함량이나 amylose함량이 높았다. 맥아 60%에 쌀 40%를 혼합하여 맥즙을 제조한 결과 색, 점도, pH, 수용성 단백질, 추출물함량(% extract), 당의 소성에서 Indica품종은 Japonica품종과 큰 차이를 나타내지 않았다. 국내에서 생산되는 쌀로 제조된 맥즙은 수용성 단백질, pH, 점도 등에서는 미국산 쌀로 제조된 맥즙과 큰 차이를 나타내지 않았으나 추출물함량은 약간 낮은 것으로 나타났다. 쌀을 혼합하여 제조한 맥즙의 glucose와 maltose함량은 맥아만으로 제조된 맥즙보다 더 낮았다.

• Mycobiology
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• 제41권3호
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• pp.139-144
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• 2013

Makgeolli is a traditional cloudy-white Korean rice wine with an alcohol content of 6~7%. The present study investigated the morphological characteristics, carbon-utilizing ability, fatty acid composition, alcohol resistance, glucose tolerance, and flocculence of Saccharomyces cerevisiae Y98-5 and Pichia anomala Y197-13, non-S. cerevisiae isolated from Nuruk, which is used in brewing Makgeolli. Similar morphological characteristics were observed for both isolated wild yeast strains; and the carbon source assimilation of Y197-13 differed from that of other P. anomala strains. Strain Y197-13 was negative for D-trehalose, mannitol, arbutin, I-erythritol, and succinic acid. The major cellular fatty acids of strain Y197-13 included C18:2n6c (33.94%), C18:1n9c (26.97%) and C16:0 (20.57%). Strain Y197-13 was Crabtree-negative, with 60% cell viability at 12% (v/v) ethanol. The flocculation level of strain Y197-13 was 8.38%, resulting in its classification as a non-flocculent yeast.

• 한국식품저장유통학회지
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• 제20권4호
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• pp.482-487
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• 2013

시판되는 발효식초 7종을 대상으로 품질특성을 비교 분석하였다. pH는 감식초가 가장 높았으며, 양조식초, 무화과 식초, 쌀식초, 사과식초, 현미식초, 매실식초 순으로 나타났다. 총산의 경우 현미식초, 사과식초, 매실식초가 6.33~6.57%의 범위를 보여 타 시료에 비해 조금 높은 결과를 보였다. 유리아미노산 함량은 양조식초>무화과식초>감식초>쌀식초>매실식초>사과식초 순으로 나타났으며, ${\gamma}$-aminobutyric acid(GABA) 함량이 무화과식초와 감식초에서 타 시료에 비해 높게 분석되었다. 항산화성분인 총 폴리페놀 함량은 감식초>무화과식초>양조식초>쌀식초 순으로 나타났으며, 총 플라보노이드 함량 역시 그 경향이 총 폴리페놀 함량과 일치하였다. 이상의 결과로 보아 현재 상업적으로 대량 판매를 하지 않는 무화과 식초가 타 식초에 비해 유기산 성분과 GABA 함량이 풍부한 기능성 식초를 제조하는데 좋은 대안이 될 것으로 사료된다.

• 한국식품저장유통학회지
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• 제2권2호
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• pp.269-276
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• 1995

Uncooked rice Tackju was prepared from the groud rice with different particle size such as 12, 20, 35 and 50 mesh, and its characteristics were analysed during the brewing. Reducing sugar and ethanol contents as well as yeast cell counts were the highest in main mash and Tackju prepared from 20 mesh fraction. Especially, reducing sugar content was about. 1.5-2.5 times as much as that obtained from 35 or 50 mesh fraction. The final concentration of ethanol in main mash prepared from 20 mesh fraction was 14.8%(v/v). It was about 1.5%(v/v) higher than the lowest one [13.35%(v/v)] which was prepared from 12 mesh fraction. No significant difference In total acidity was observed. Sensory evaluation revealed 20 or 35 mesh Tackju to be the best in overall preference, especially in sweet and refreshing tastes.