• Journal of Microbiology and Biotechnology
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• 제27권2호
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• pp.226-233
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• 2017

Jeung-pyun, a fermented rice cake, is prepared by fermenting rice sourdough using makgeolli, a traditional Korean rice wine, in the presence of yeast and lactic acid bacteria (LAB). The goal of this study was to conduct biochemical and microbial analyses of five different rice sourdoughs, each fermented with a different commercial makgeolli, using culture-dependent and culture-independent approaches. All sourdough samples fermented with different makgeolli for 6.5 h showed different profiles in pH, total titratable acidity, organic acid concentration, and microbial growth. LAB belonging to different genera were identified based on colony morphology on modified MRS and sourdough bacteria agar medium. PCR-denaturing gradient gel electrophoresis analyses of the five sourdoughs showed different bands corresponding to LAB and yeast. 16S/26S rRNA gene sequence analyses of the samples confirmed that the predominant LAB in the five fermented rice doughs was Lactobacillus plantarum, Lb. pentosus, and Lb. brevis. Various other Lactobacillus spp. and Saccharomyces cerevisiae were common in all five fermented samples. This study provides comprehensive and comparative information on the microflora involved in fermentation of rice sourdough and signifies the need to develop effective starters to enrich the quality of jeung-pyun.

• 한국조리학회지
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• 제22권5호
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• pp.1-12
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• 2016

본 연구에서는 찐빵의 영양성과 품질을 향상시키기 위한 현미발효액, 현미 sourdough을 만든 후, 첨가량을 달리하여 찐빵을 제조한 다음 이화학적, 관능적 특성을 측정하였다. 반죽의 pH 및 적정산도를 측정한 결과는 현미 sourdough 첨가량에 따라 유의적으로 낮아지는 경향을 보였으며, 대조구의 적정산도는 시료간의 유의한 차이가 있었다. 발효시간에 따른 반죽의 부피는 대조구와 각 시료간의 유의적인 차이가 없었으며, 발효 15분에는 대조구에서 가장 크게 부피가 증가하였고, D시료에서 가장 낮은 부피를 보였다. 찐빵의 부피 및 비용적의 경우, B 시료에서 3.34로 가장 높았고, 각각의 시료에서 발효시간에 따른 유의한 차이를 보였다. 지름은 B 시료에서 88.11로 가장 높았고, D 시료에서 79.04로 가장 낮았으며, 시료간의 유의한 차이가 나타났다. 찐빵의 높이는 대조구에서 42.91로 가장 높았고, D 시료에서 41.87로 가장 낮았으며, 시료간의 유의한 차이를 보였다. 찐빵의 단면구조를 살펴본 결과, 부피와 비용적이 가장 높게 나타난 B 시료의 기공이 가장 크고 조직의 결이 일정하게 분포되어 있었다. L값은 대조구보다 첨가구에서 높은 경향을 보였고, a값은 현미 sourdough의 첨가량이 증가할수록 높게 나타났고, b값은 찐빵의 부피와 비용적이 클수록 낮게 나타나 L값과 유사한 경향을 보였다. 경도, 점착성, 씹힘성에서 D 시료에서 가장 높았고, B 시료에서 가장 낮았으며, 시료간의 유의한 차이가 나타났다. 전체적인 선호도를 측정한 결과, 향, 맛, 외형 및 질감에서 가장 높은 선호도를 나타낸 B 시료에서 가장 높았고, 맛, 외형 및 질감 등에서 가장 낮은 선호도를 나타낸 D 시료에서가장 낮았으며, 각 시료간의 유의한 차이를 보였다.

• 동아시아식생활학회지
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• 제18권1호
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• pp.87-94
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• 2008

In this study, a nanatural fermentation starter formulation was developed for manufacturing bread products by substituting baker's yeast with naturally fermented raisin extract and sourdough. Four experimental groups containing 2.5, 5.0, 7.5, 10% naturally fermented raisin extract per 2,000 g of flour were compared based on quality characteristics, including the fermentation power on dough expansion, specific volume, baking loss, water activity, color, textural characteristics, and internal surface appearance. The activities of the naturally fermented raisin extract were examined in terms of pH changes, total titratable acidity, brix, and viable yeast counts. The raisin extract, which was cultured for 7 days at 30$^{\circ}C$, smelled of alcohol and produced $CO_2$. Yeast were also found in the extract after separation. As the incubation time of the raisin extract and sourdough increased, pH decreased, while total titratable acidity increased. The brix of the raisin extract increased until the $2^{nd}$ day of fermentation, and viable yeast counts increased until the $5^{th}$ day however, these gradually decreased by the $7^{th}$ day. The fermenting power on dough expansion increased in the bread with increasing incubation time. The bread samples containing 7.5% and 10% raisin extract had significantly higher specific volumes than the other samples. Baking loss was minimal with the 2.5% extract substitution. In analyzing the crumb, water activity, redness, and yellowness were highest in the 10.0% raisin extract bread samples, and lightness was maximal in the 5.0% group. In terms of textural characteristics, hardness was lowest with the 2.5% extract substitution. Gumminess, springiness, and chewiness were not significantly different among the bread samples. Cohesiveness was highest at the 7.5% extract substitution level, and resilience was lowest at the 10% level. In conclusion, based on the results, a natural fermentation starter formulated with 2.5% naturally fermented raisin extract (1 part raisins and 1.5 parts water) and 70% sourdough (1 part rye flour and 1 part water) has high potential as a baker's yeast substitute for making naturally fermented bread.

• 식품과학과 산업
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• 제47권3호
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• pp.57-63
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• 2014

• 한국식품영양과학회지
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• 제33권7호
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• pp.1180-1185
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• 2004

본 연구는 sourdough 제빵에 관여하는 우수한 효모와 젖산균을 분리, 선별하고 이들의 최적 배지 조성을 연구하였다. 1차 분리된 젖산균 115균주 중 항균성이 우수하고, 산 생성 및 향이 우수한 균주를 선별하여 동정한 결과 Leuconostoc sp.로 나타났다. 효모는 8개 균주를 1차 선별하였으며, 발효와 향이 우수한 균주를 선별하여 동정한 결과 Saccharomyces sp.로 동정되었다. 당 발효성을 실험한 결과, glucose와 sucrose에서 생육이 우수하였으나, 상업적으로 많이 사용하고 있는 sucrose가 좋을 것으로 판단되었다. 젖산균은 밀가루배지에 1% sucrose첨가만으로 생육이 우수하였으나, 효모인 경우는 증식이 더 필요하였다. 추가적으로 분리된 효모의 생육 실험을 하여 나타난 최적배지조성은 wheat flour 0.5%, peptone 0.5%, sucrose 3%로 나타났으며, 젖산균인 경우는 peptone의 첨가없이 wheat flour 0.5%, sucrose 1%로 나타났다.

• 동아시아식생활학회지
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• 제23권3호
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• pp.349-356
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• 2013

When making a yellow layer cake, an existing chemical leavening agent, sourdough starter powder, was used instead of using baking powder in order to produce batter where the acid agent in the baking powder was reduced using baking soda. The control group had the lowest share of the batter and therefore had the highest specific volume. In a test group, the share of SP4 was low and therefore, the specific volume was high. In terms of physiochemical characteristics, the volume, symmetry and uniform index was high in SP4 in the test group. The control group had the highest moisture content followed by SP4. In terms of texture, the control group had the lowest hardness and highest springiness. In the test group, SP4 had the lowest hardness and highest springiness. The result of the sensory evaluation indicates that SP4 had the best taste and flavor. In terms of overall preference, SP4 showed significantly higher preference overall. However, it did not show any significant difference compared to the control group.

• Journal of Microbiology and Biotechnology
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• 제27권10호
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• pp.1736-1743
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• 2017

Sourdough is made by fermentation of dough by lactic acid bacteria (LAB) and yeast to improve bread properties like volume, flavor, and texture. A Korean traditional sourdough was made by fermenting rice flour with rice wine (makgeolli) and used to make sponge-like bread (jeung-pyun). The aim of this study was to investigate the microbial diversity of makgeolli products and their influence on the organoleptic quality of jeung-pyun. Three commercial makgeolli were tested for jeung-pyun production, with each product exhibiting varied dough swelling rates and organoleptic qualities, and among them, J-product was ranked highest in texture and taste. Microbial analysis of the three makgeolli also showed a big difference in their population and diversity. J-product had the highest LAB and yeast counts, and the predominant species were Lactobacillus casei, Lactobacillus brevis, Leuconostoc pseudomenteroides, and Saccharomyces cerevisiae. Using J-product, sourdough was fermented at $25^{\circ}C$, $30^{\circ}C$, and $35^{\circ}C$, and the microbial growth in and textural properties of jeung-pyun were examined by instrumental and sensory tests. At high temperature ($35^{\circ}C$), the rates of dough swelling and acidification were fast due to rapid microbial growth mainly caused by LAB, resulting in a short leavening time and soft and sour jeung-pyun. Sensory tests showed consumer preference for the soft and mild-sour jeung-pyun. This study shows that LAB in makgeolli play key roles in production of jeung-pyun, influencing the textural and sensory properties. For the production of high-quality jeung-pyun, development of LAB starters with high gas productivity and low acidity and establishment of an optimal fermentation procedure for rice dough are necessary.

• 한국가정과학회:학술대회논문집
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• 한국가정과학회 2004년도 학술대회
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• pp.89-89
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• 2004

• Journal of Microbiology and Biotechnology
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• 제29권11호
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• pp.1729-1738
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• 2019

In sourdough fermentation, lactic acid bacteria perform important roles in the production of volatile and antimicrobial compounds, and exerting health-promoting effects. In this study, we report the probiotic properties and baking characteristics of Lactobacillus plantarum SPC-SNU 72-2 isolated from kimchi. This strain is safe to use in food fermentation as it does not carry genes for biogenic amine production (i.e., hdc, tdc, and ldc) and shows no β-hemolytic activity against red blood cells. The strain is also stable under simulated human gastrointestinal conditions, showing tolerance to gastric acid and bile salt, and adheres well to colonic epithelial cells. Additionally, this strain prevents pathogen growth and activates mouse peritoneal macrophages by inducing cytokines such as tumor necrosis factor-α, interleukin (IL)-6, and IL-12. Furthermore, the strain possesses good baking properties, providing rich aroma during dough fermentation and contributing to the enhancement of bread texture. Taken together, L. plantarum SPC-SNU 72-2 has the properties of a good starter strain based on the observation that it improves bread flavor and texture while also providing probiotic effects comparable with commercial strains.

• 한국미생물·생명공학회지
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• 제49권4호
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• pp.501-509
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• 2021

The increasing demand for baked products has given a boost to research on isolation and selection of novel yeast strains with improved leavening activity. Twelve sourdough samples were collected from several localities of the Fez region in Morocco. The pH and total titratable acidity (TTA) values of these samples varied from 3.03-4.63 and 14-17.5 ml of 0.1 N NaOH/10 g of sourdough, respectively, while yeast counts ranged from 5.3 6.77 Log CFU/g. Thirty-two yeast isolates were obtained and evaluated for their leavening ability. Out of all isolates, four yeasts molecularly identified as Saccharomyces cerevisiae (three strains) and Kluyveromyces marxianus (one strain) showed highest specific volumes of 4.69, 4.55, 4.35 and 4.1 cm³/g, respectively. These strains were further assessed for their tolerance to high concentrations of salt, sugar, elevated temperatures, and low pH conditions. K. marxianus showed higher resistance than the S. cerevisiae. Thus, Moroccan sourdoughs harbor technologically relevant yeasts that could be used as potential starters for bread preparation.