• 한국식품조리과학회지
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• 제33권1호
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• pp.94-103
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• 2017

Purpose: This study developed sourdough bread according to consumers' preferencesby shortening the sourdough fermentation process time through addition of makgeolli to sourdough. Methods: Fermentation time was measured by adding makgeolli and water to wheat flour. Results: Fermentation time was shorter than that of starter made with only water and flour, with 5 hours of primary fermentation and 3 hours of secondary fermentation. The optimum mixing ratio was 400 g of flour, 192 mL of water, and 48 mL of makgeolli. An increase in makgeolli sourdough content decreased crude protein and moisture contents of white bread. Crude fat and ash contents increased, and volume of bread was decreased as sourdough increased. The height of bread prepared with makgeolli sourdough was lower than that of bread without makgeolli sourdough. According to the results of the texture measurement, hardness, gumminess, and chewiness of sourdough group were lower as the addition of sourdough increased. Addition of makgeolli sourdough to white bread resulted in decreased lightness, but increased yellowness of white bread. Preparation of white bread with addition of sourdough improved taste and flavor compared to bread prepared only with wheat flour. Conclusion: The highest sensory preference was observed for white bread prepared whit 5 g of sourdough.

• 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.

• 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.