• Journal of Microbiology and Biotechnology
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• 제32권3호
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• pp.307-316
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• 2022

Yeasts play an important role in spontaneous fermentation of traditional alcoholic beverages. Our previous study revealed that a mixed-consortia of both Saccharomyces and non-Saccharomyces yeasts were responsible for fermentation of khadi, a popular, non-standardized traditional beverage with an immense potential for commercialization in Botswana. Functional characterization of isolated fermenting yeasts from mixed consortia is an indispensable step towards the selection of potential starter cultures for commercialization of khadi. In this study, we report the characterization of 13 khadi isolates for the presence of brewing-relevant phenotypes such as their fermentative capacity, ability to utilize a range of carbon sources and their ability to withstand brewing-associated stresses, as a principal step towards selection of starter cultures. Khadi isolates such as Saccharomyces cerevisiae, Saccharomycodes ludwigii and Candida ethanolica showed good brewing credentials but Lachancea fermentati emerged as the isolate with the best brewing attributes with a potential as a starter culture. However, we were then prompted to investigate the potential of L. fermentati to influence the fruity aromatic flavor, characteristic of khadi. The aroma components of 18 khadi samples were extracted using headspace solid phase micro-extraction (HS-SPME) and identified using a GC-MS. We detected esters as the majority of volatile compounds in khadi, typical of the aromatic signature of both khadi and L. fermentati associated fermentations. This work shows that L. fermentati has potential for commercial production of khadi.

• 한국식품영양학회지
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• 제9권3호
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• pp.236-241
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• 1996

Starter cultures were developed for the extension of the shelf life of bread. Lactobacillus plantarum and Bifidoacterium longum were selected as the mixed culture with Propionibacterium freudenreichii. P. fredenreichii with B. longum and L. plantarum produced 2.261% and 1.715% total acid, and pH value of cultured solutions was near 3.95. Propionic acid was produced 14 ~16 mg/ml by P. freudenreichii with L. plantarum and B. longum during 17 days, which was more than that of L. brevis. The pH values of the bread were 4.83 and 4.89 in respect to B. longum and L. plantarum when the fermented products were used to make the bread. Mold was not found for 10 days of storage of the bread at room temperature when the fermented products of B. longum were used for making bread. 37$^{\circ}C$, pH 6.0 and the lowest agitation were optimum conditions for the production of propionic acid in the scaled up fermentation.

• 한국식생활문화학회지
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• 제26권2호
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• pp.190-197
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• 2011

Chungtaejeon is a traditional tea introduced in the age of the Three States and is the only "Don-cha" culture in the world that survived on the southwestern shore of Korea. To restore Chungtaejeon and to make the tea with consistent quality, the microorganisms involved in traditional type fermentation of Chungtaejeon were isolated, and the tea was prepared with high fermentation ability starters. The sensuous characteristics of Chungtaejeon were also examined. Only Bacilli were found in 3 and 5 year aged Chungtaejeon samples. The Lactobacilli were isolated from properly fermented kimchi and one of them showed high growth capability in media containing green tea extract and also showed strong antagonistic activity against methicillin-resistant Staphylococcus aureus, S. aureus, Salmonella, and E. coli. It was identified and named Lactobacillus plantarum CHO25. Chungtaejeon was fermented with a single starter of L. plantarum CHO25 and with a mixed starter (L. plantarum CHO25, Saccharomyces cerevisiae and Bacillus amyloliquefaciens CHO104). The single fermented sample had the highest cell growth after 5 days of inoculation and the level decreased slowly thereafter. The mixed fermented sample showed strong growth of S. cerevisiae. The highest hunter values were the a value of the single fermented sample and the b value of the mixed sample. The single fermented tea showed the best incense score.

• 한국식품영양학회지
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• 제29권5호
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• pp.801-807
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• 2016

In Western countries, kimchi, the Korean traditional fermented cabbage, is considered to be a healthy. However, it is one of the main sources of the high sodium content of the Korean diet. In order to decrease the sodium content, we manufactured a low-sodium kimchi (LK, salinity 1.0%) and 4 additional low-sodium kimchi starters in which each of 4 lactic acid bacteria (Lb. sakei 1, Lb. sakei 2, Lb. palntarum and W. koreensis) were added. The LKL1 to LKL4 samples were prepared by adding 4 single LAB starters, each with an inoculum size of $10^6CFU/g$, when the cabbage was mixed with kimchi sauce. The kimchi starters were fermented at $10^{\circ}C$ until reaching 0.5% acidity, and then stored at $-1.5^{\circ}C$ until reaching 0.75% acidity. The pH and acidity of the starter kimchi changed more rapidly in the early phase of fermentation (up to 0.75% acidity) than control low-sodium kimchi. After the acidity of the kimchi starters reached 0.75% it remained constant. As the fermentation progressed, the total aerobic and lactic acid bacteria concentrations in the kimchi starter with added Lb. sakei 1 were the same as in the control low-sodium kimchi. The low-sodium kimchi fermentation of the kimchi starter with added Lb. palntarum progressed differently due to a difference in acid resistance. The kimchi starter with added Lb. sakei 2 had an overall liking score that was slightly higher than that of the control low-sodium kimchi due to a lower off-flavor.

• Journal of Dairy Science and Biotechnology
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• 제36권3호
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• pp.178-185
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• 2018

Kefir, which originates in the Caucasian mountains, is a cultured milk beverage produced by a combination of acidic and alcoholic fermentation. Kefir products are commonly used as food vehicles to deliver health-promoting materials including kefran and lactic acid bacteria to consumers. The aim of this study was to develop a freeze-dried starter culture without yeast and assess the suitability of kefir-like dairy products for the growth of lactic acid bacteria and the acidification of milk. Pasteurized whole milk (SNF 8.5%) stored at $25^{\circ}C$ was aseptically inoculated with starter cultures (0.002% w/v); it was kept at $25^{\circ}C$ until the pH attained a value of 4.6. Ten grams of the kefir-like product sample was diluted with 90 mL of 0.15% peptone water diluent in a milk dilution bottle, followed by uniform mixing for 1 min. Viable cells of Lactobacillus species were enumerated on modified-MRS agar (pH 5.2), with incubation at $37^{\circ}C$ for 48 h. Viable cells of Lactococcus species were enumerated on M17-lactose agar, with incubation at $32^{\circ}C$ for 48 h. The pH attained a value of 4.6 after fermentation for 9 h 30 min (Starter 1), 9 h 45 min (Starter 2), and 12 h (Starter 3). The viable cell count of Lactobacillus sp. and Lactococcus sp. was initially $10^5{\sim}10^6CFU/g$; it increased significantly to $10^9CFU/g$ after 12 h of incubation. During the storage of the kefir-like products at $4^{\circ}C$ for 1 4 days, the total viable cell numbers were unchanged, but the pH decreased slightly. The consistency of the kefir products increased gradually during the storage. The organoleptic properties of the kefir products fermented using the new starter culture are more desirable than those of commercial kefir. These results suggest that the newly developed starter culture without yeast could be suitable for kefir fermentation.

• 동아시아식생활학회지
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• 제24권1호
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• pp.53-61
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• 2014

본 연구에서는 다양한 발효균 starter를 이용한 당화 혼합곡물 음료 개발의 가능성을 확인하고자 하였다. 혼합곡물의 수분 흡수 지수를 측정한 결과, 쌀 60분, 차조 120분, 기장 120분, 메밀 120분, 수수 180분으로 나타났다. 7종의 균주와 2가지의 혼합 균주를 이용하여 제조된 발효균 starter의 당화력은 0.13~3.58 units/g으로 형성되었다. Starter를 이용하여 제조한 당화 혼합곡물 음료의 가용성 고형분($^{\circ}Brix$)은 당화가 진행되는 동안 증가하는 것이 관찰되었고, 15시간 동안 당화를 진행하는 것이 효율적인 것으로 평가되었으며, C sample에서 $17.55{\pm}0.05$로 가장 높게 관찰되었다. 수분 함량은 77.9~80.7%로 높게 나타났으며, 조단백질, 조지방, 조회분 함량은 3.7~7.5%, 0.37~0.97%, 1.81~7.47%로 다양하게 나타났다. 음료의 점도를 측정한 결과, 60~528.3 CP로 다양하게 나타났다. 또한 음료의 유리아미노산을 측정한 결과, 아르기닌과 필수 아미노산이 다양하게 함유되어 있는 것으로 나타났다. 그 중 G sample에서 필수 아미노산으로 알려진 루신, 이소루신, 발린, 트레오닌과 단맛을 나타내는 알라닌, 라이신, 세린의 함량이 다른 당화 음료보다 높게 분석되었다. 이와 같은 결과는 발효균 starter가 가지는 고유의 효소 활성에 따라 나타난 것으로 예상된다. 이와 같이 Aspergillus oryzae CF1003, Asp. acidus KACC46420, Rhizopus delemar KACC-46149, Rhz. oryzae KACC45714, Rhz. oryzae KACC46148, Asp. oryzae CF1001, Asp. acidus CF1005의 7가지 균주 각각을 이용하여 제조한 starter와 이 균주들을 혼합한 starter를 이용한 당화물의 제조에 관한 기초 자료와 일반 성분을 검토함으로써 혼합곡물을 이용한 기능성 식품 개발을 위한 기초 자료를 제시하였다.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2005년도 추계학술발표대회 논문집
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• pp.256-259
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• 2005

Mixed-mode interlaminar fracture toughness of carbon fabric/epoxy composites, which are applicable to tilting train carbody, was evaluated through the MMB (Mixed-mode bending) test. Specimens were made of CF3327 plain woven fabric with epoxy and a starter delamination at one end was made by inserting Teflon film with the thickness of 12.5 μ m. Mixed-mode interlaminar fracture test was conducted for 6 types of specimens with the mode II ratio of 20 ,35, 50, 65, 80, 90%. Also crack propagating behaviors and fractured surfaces were examined through an optical travelling scope and a scanning electron microscope, respectively.

• 한국식품과학회지
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• 제12권4호
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• pp.313-323
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• 1980

고추장의 양조법을 개선하기 위한 계속적인 연구로서 Saccharomyces rouxii, Torulopsis versatilis, Torulopsis etchellsii 등의 효모를 혼용첨가하여 여름철에 담금한 고추장 숙성과정 중의 효소력, 여러 성분 등을 비교 검토하고 관능검사한 결과는 다음과 같다: 고추장 숙성과정 중의 전분액화력은 담금 후 $20{\sim}60$일 경에, 전분당화력은 $20{\sim}30$일경에, 산성 protease는 $20{\sim}40$일경에 각각 최대활성을 나타낸 후 불규칙적인 증감현상을 보이면서 숙성 후기에는 현저히 감소하였다. 최대 활성시의 전분액화력과 당화력은 T. versatilis와 T. etchellsii의 혼용구가 다소 높게 나타났다. 에틸 알콜 량은 S. rouxii와 T. etchellsii의 혼용구 및 S. rouxii와 T. versatilis의 혼용구에서 담금 후 10일경에 $2.75{\sim}2.9%$의 높은 함량을 나타내었으나 동일기간 중의 효모 무첨가구 및 T. versatilis와 T. etchellsii의 혼용구에서는 $0.55{\sim}1.60%$로 현저히 낮았다. 숙성 20일 이후 에틸 알콜의 함량은 $2.3{\sim}2.8%$로서 전시험구가 비슷한 함량이였고 숙성 후기에는 다소 감소하였다. 환원당량은 담금 직후보다 10일 후에 월등히 증가되었는데 이중 효모 무첨가구 및 T. versatilis와 T. etchellsii의 혼용구가 현저한 증가를 나타내었다. 그러나 숙성 40일 이후는 각 시험구간의 함량은 비슷하였다. 아미노질소함량은 시험구 모두 담금 후 10일경에 급격히 증가하여 숙성 90일 경까지 대체로 증가현상을 보였는데 이중 T. versatilis와 T. etchellsii의 혼용구가 다소 높은 함량을 나타내었다. 고추장의 관능검사 결과 숙성 30일의 경우 향기는 효모 첨가구가 효모 무첨가구에 비하여 월등히 우수하였고 맛과 색도 좋은 결과로 나타났다. 이중 맛은 T. versatilis와 T. etchellsii의 혼용구가, 향과 색은 S. rouxii와 T. etchellsii의 혼용구가 각각 좋은 것으로 나타났다. 숙성 180일의 경우도 맛, 향기, 색 모두 효모 첨가구가 우수하였는데 이 중 T. versatilis와 T. etchellsii의 혼용구가 가장 우수하였다. 따라서 고추장 양조에 있어서는 숙성기간이나 제품의 특성에 알맞게 적합한 효모를 혼용첨가하므로 고추장의 품질을 개선할 수 있다고 생각된다.

• 한국식품영양학회지
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• 제11권6호
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• pp.683-688
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• 1998

This study was conducted to develop optimal composition of flour brew in order to economically utilize flour brew inoculated by lactic acid bacteria as a starter(mother sponge) in bread-making. Two flour brews were prepared ; one with flour and water, the other with flour, water and NaCl. Various nutrients were added to both flour brews and Lactobacilli deMan Rogosa and Sharpe (MRS) broth to investigate the effect of them on growth and activities of Streptococcus thermophilus, Lactobacillus brevis and their mixed culture in flour brews to be tested with incubation at 37$^{\circ}C$. The growth of Streptococcus thermophilus, Lactobacillus brevis and their mixed culture was stimulated by addition of NaCl with 0.85% concentratin and more by mixed culture than by single lactic acid bacteria, resulting in 3 hrs reduction in cultivation and more by mixed culture than by single lactic acid bacteria, resulting in 3 hrs reduction in cultivation time. the addition of 3% glucose to flour brew with NaCl was observed to enhance acid productioni by mixed culture. Yeast extract greatly affected growth and activities of mixed culture of lactic acid bacteria in flour brew with NaCl and its optimum level of this additive in flour brew with NaCl was approximately 1.0%. The optimal composition of flour brew for mixed culture of lactic acid bacteria was suggested as follows; flour 100g, water 300g, NaCl 3.46g, glucose 12.48g, yeast extract 3.46g.

• 생명과학회지
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• 제6권1호
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• pp.27-33
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• 1996

치즈숙성과정 중에서 Lactococcus lactis subsp. cremoris KH (lac$^{+}$ prt$^{+}$ ) and KHA (lac$^{-}$ prt$^{-}$ )의 혼합균에 의하여 일어나는 반응을 연구하였다. 혼합균의 성장 특징은 한쪽 균의 도움에 의하여 같이 성장하는 특징을 나타내었으며, 이 혼합균의 단백질분해효소의 양은 충분히 적었다. 이 결과로부터 치즈숙성과정 중에 홈합균의 균밀도가 높게 유지되더라도, 이 혼합균에 의하여 생성되는 쓴 맛의 생성량은 큰 문제가 되지 않는다는 결론을 얻을 수 있다. 그러므로, 치즈 숙성 과정을 촉진시키는데 있어서 KHA1의 혼합균은 좋은 치즈스타터균의 하나라고 할 수 있다.