• Korean journal of food and cookery science
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• v.21 no.4 s.88
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• pp.399-405
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• 2005

This study investigate the effects of variations in the mont of raw yeast added to Jeung-Pyun on the quality changes during a storage period ranging from $0\~4days.$ The results of height and volume showed that Jeung-Pyun prepared with the $0.5\%$ raw yeast added had the most fermentation. The rheological properties measured by texturometer were significantly different among the raw yeast-added Jeung-Pyun during the storage period. The degree of hardness of raw yeast-added Jeung-Pyun slowly increased during storage at room temperature ($20^{\circ}$). Hunter's color test showed no significant differences. In sensory evaluation, Jeung-Pyun prepared with $0.5\%$ raw yeast-added had the most favorable quality.

• Korean journal of food and cookery science
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• v.16 no.3
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• pp.267-271
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• 2000

The present study was designed to develop the standardized formula for the preparation Jeung-Pyun with added raw soy flour and to investigate the applicability of Jeung-Pyun as the substitute of regular pizza crust made with wheat flour. The effect of adding raw soy flour at 3%, 5% level on fermentation time and viscosity of batters and texture and general desirability of Jeung-Pyun pizza were also studied. As the level of raw soy flour was increased the time required for 1 st and 2nd fermentation decreased and viscosity of batters increased significantly. Jeung-Pyun crust after steaming found to have appropriate texture and form for a substitute of wheat flour pizza crust. Texture parameters determined by QST showed that Jeung-Pyun crust with added raw soy flour had lower values in hardness, cohesiveness and gumminess without any significant difference. However, chewiness of 5% raw soy flour group was significantly lower than control group. Texture of Jeung-Pyun crust and general desirability of Jeung-Pyun pizza were determined by sensory evaluation. Textural parameters of Jeung-Pyun crust were evaluated on the basis of hardness, cohesiveness, adhesiveness, tenderness and wetness. As a result of sensory evaluation Jeung-Pyun crust made with 5% raw soy flour had significant lower values in hardness, cohesiveness, tenderness and wetness than the control. However, the textural parameters between control and 3 % raw soy flour group were not significantly different. Jeung-Pyun pizza with topping were evaluated by sensory panel. Jeung-Pyun pizza made with 3% raw soy flour received the highest score in apperance and general desirability without any significant difference. 5% raw soy flour group had significantly lower score in general desirability among 3 treatment groups. In conclusion, Jeung-Pyun crust made by traditional Jeung-Pyun preparation method will be a good alternative to replace wheat flour pizza crust. Adding raw soy flour at 3% level did not affect the quality of Jeung-Pyun crust and had an effect of promoting fermentation. Jeung-Pyun Pizza crust was expected to have tender texture and slower retrogradation rate than regular pizza crust with wheat flour.

• Journal of Microbiology and Biotechnology
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• v.27 no.10
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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.

• Korean journal of food and cookery science
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• v.20 no.4
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• pp.380-386
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• 2004

This study was carried out to investigate the quality characteristics of Jeung-Pyun with respect to the addition ratio of pigmented rice and fermentation method. As the mont of pigmented rice was increased, the moisture content of the products added with yeast tended to increase more than those made in the traditional way. Regardless of fermentation method, L value and b value of Jeung-Pyun without pigmented rice were higher than those of Jeung-Pyun with pigmented rice, for which the values were significantly low. The samples with 5% or 10% pigmented rice had a high degree of expansion. The other samples showed no visible difference. The hardness, cohesiveness, springiness and chewiness tended to decrease. On the other hand, the adhesiveness was increased. In both fermentation methods, as the amount of pigmented rice was increased, the gelatinization degree was raised. In sensory evaluation, the characteristics of Jeung-Pyun with 30% pigmented rice were very poor, except for the characteristics on pore uniformity. The other samples and both fermentation methods were hardly different.

• Korean Journal of Food Science and Technology
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• v.25 no.6
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• pp.655-665
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• 1993

The added levels of dongdong-ju, soy bean and fermentation time were selected as factors affecting the quality of Jeung-pyun (Korean fermented steamed rice cake) through pretest. The standing height ratio was significantly raised after the 1st and 2nd fermentation by the soy bean treatment. As the amount of dongdong-ju and soy bean were increased, the values of specific volume and expansion ratio for Jeung-pyun were increased. The effects of fermentation time did not show any significant differences. The pH of Jeung-pyun dough was significantly higher when the amount of dongdong-ju decreased and the amount of soy bean increased. Reducing sugar content of Jeung-pyun significantly augmented with raised amount of soy bean. As the amount of soy bean was increased, the hardness, springiness and cohesiveness of Jeung-pyun measured by rheometer significantly decreased. The optimum conditions for Jeung-pyun preparation were found to be 30g dongdong-ju, 2g soy bean solid and 180 minutes of fermentation time per 100g rice flour basis. Soy bean treatment had primary influence on Jeung-pyun preparation.

• Journal of Microbiology and Biotechnology
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• v.27 no.2
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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 the Korean Society of Food Science and Nutrition
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• v.21 no.5
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• pp.525-533
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• 1992

To improve the food quality of traditional Jeung-pyun(Korean fermenfed rice cake), effect of mixed ingredients on the quality of protein enriched product was studied. Changes were evaluated in chemical and textural properties of protein enriched Jeung-pyun altered by fermentation time, temperature, and steaming time. The maximum volume wxpansion was noted in dough mixed with rice flour(100 g), soy flour(25 g), sucrose(20 g), Tak-ju(50 ml) and water(10 ml), and then fermented at $35^{\circ}C$ for 3 hours. Soy protein isolate(SPI) enriched rice dough had a maximum expanded volume when 15g(w/w) of SPI, 20g(w/w) of sucrose, 60ml(v/w) of Tak-ju and 50ml(v/w) of water added into 100g rice flour, and then fermented at $30^{\circ}C$ for 2 hours. Steaming after fermentation made the smaller volume of bulk $45^{\circ}C$-50% of the initial volume be showed just after fermentation. Protein enriched Jeung-pyun prepared under the maximal volume endowing conditions showed the best protein quality(protein digestibility and protein efficiency ratio) and starch structure which was susceptible towards enzyme reaction. The improved starch quality of protein enriched Jeung-pyun could be confirmed by reducing power, gelatinization degree and amylose content. Jeung-pyun riched with soy flour at 20% level or with SPI at 5% showed the best overall quality by sensory and textural property but it had a problem in browning.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.1
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• pp.101-108
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• 1992

Changes were evaluated in chemical and textural properties of Jeung-pyun (fermented rice cake) altered by the particle size of rice flour, amount of added Tak-ju (Korean traditional unrefined liquor) and sucrose, fermentation time and temperature, and steaming time. Particle size of polished rice flour did not affect the volume expansion during fermentation of rice dough by Tak-ju. The maximum expanded volume was noted in the dough, containing 20% sucrose (rice flour vs sucrose = 5 : 1, w/w), fermented at $35^{\circ}C$ for 3 hours. Any volume expansion was not occurred in rice dough without sucrose. The highest value of reducing power and gelatinization degree were observed in the rice dough with Tak-ju (rice flour vs Tak-ju = 2 : 1, w/v), while the lowest blue value was revealed in that case. Steaming followed after fermentation made the smaller volume of bulk by $45{\sim}50%$ of the initial volume be showed just after fermentation. Jeung-pyun prepared under the conditions could give maximum expanded volume by fermentation showed the best overall quality by sensory and textual properties.