• Journal of the East Asian Society of Dietary Life
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• v.12 no.1
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• pp.38-46
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• 2002

This study was carried out in order to investigate dextran formation and internal structure during fermentation of the oligosaccharide Jeung-Pyun. The dextran and sugar reducing contents of Jeung-Pyun batter and the specific volume and the internal structure of Jeung-Pyun were analyzed as a function of fermentation time. The specific volume of Jeung-Pyun peaked at the 7th hour of fermentation. The dextran content of Jeung-Pyun batters peaked at the 7~13th hour of fermentation, and Fructooligosaccharide Jeung-Pyun had the least peak value. Reducing sugar content of Jeung-Pyun batters slowly decreased as fermentation progressed. From the air pore size and distribution of Jeung-Pyun observed by SEM, the sucrose Jeung-Pyun fermented for 3~7 hours and oligosaccharide one fermented for 7 hours were judged as the best. It was concluded that dextran may be formed by fermentation of oligosaccharides as well as sucrose and dextran has a significant role on the volume expansion of Jeung-Pyun.

• Journal of the East Asian Society of Dietary Life
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• v.17 no.6
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• pp.903-910
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• 2007

In order to make acquire a potential use for Opuntia humifusa as a natural functional food material, this study was performed to determine the quality properties of Jeung-pyun made with added Opuntia humifusa, or prickly pear powder. According to an analysis of its major components, we found that the prickly pear powder consisteds of nitrogen-free extracts (71.85%) and crude fiber (11.20%). Greater additions of prickly pear powder had resulted in significantly lower pH in the of Jeung-pyun. According to measurements on the degree of Jeung-pyun gelatinization, by means of ${\beta}$-amylase, greater additions of prickly pear powder led to the higher levels of isolated maltose, indicating that the gelatinization degree of the Jeung-pyun became higher. Also, samples with higher concentrations of prickly pear powder had a tendency toward lower water content, which allowed us to expect a longer storage duration for the Jeung-pyun. In the textural property tests the Jeung-pyun that had less hardness and greater adhesiveness (p<0.05) than the control group as the content of prickly pear powder became higher. Also, the Jeung-pyunhad lower gumminess and chewiness than the control group as the content of prickly pear powder became higher. Therefore, it is possible to prepare relatively soft Jeung-pyun using prickly pear powder. For the color differences of the Jeung-pyun samples, lower L- values, and higher a- and b -values (p<0.05) presented as the addition level of prickly pear powder became higher. According to SEM observations of the Jeung-pyun, the added prickly pear powder addition groups generally showed a smaller and more inconsistent pore size, but higher porosity, than the control group. According to sensory analyses of the Jeung-pyun, the P2 group scored highest for color item, and the P4 group generated the fermented scent. Higher additions content of prickly pear powder led to the lower score, but higher scores for adhesiveness. Finally, the P2 group achieved the highest score for overall taste.

• Korean journal of food and cookery science
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• v.23 no.6
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• pp.810-817
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• 2007

The quality properties of Jeung-pyun made with soybean protein isolate(SPI) were investigated. The SPI Jeung-pyun was manufactured using 3% whole protein, 7S protein or 11S protein(w/w). The redness values (a-values) of the Jeung-pyun were negative and the yellowness(b-value) of the control group was significantly lower compared to the other samples. The textural characteristics of the Jeung-pyun were influenced by the additions of SPI. The Jeung-pyuns containing soybean flour, whole protein, 7S and 11S protein had increases in springiness, but decreases in cohesiveness. In the sensory evaluation, overall desirability, sweetness, and moistness were highest in the whole protein group. The control group showed the highest scores for hardness and toughness, and the scores for after-taste and adhesiveness were the highest in the samples made with soybean flour. The 7S and 11S additions showed high scores in terms of color and springiness. In the analyses for consumer acceptance and sensory quality intensity, the whole protein addition had significantly higher scores for general acceptability and the Makgeolli flavor. Hardness was highest for the control group and the Makgeolli flavor was strongest with the soybean flour addition.

• 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.

• Journal of the East Asian Society of Dietary Life
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• v.24 no.2
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• pp.190-200
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• 2014

In this study, the antioxidant activity and quality characteristics of the Korean traditional food jeung-pyun made with ju-bak powder were investigated. Jeung-pyun added with 10% ju-bak powder had a total polyphenol content of 54.27%, DPPH free radical scavenging activity of 91.98%, reducing power of 0.51% and SOD-like antioxidant activity of 18.21%. Jeung-pyun added with ju-bak powder had a moisture content of 52.65 to 46.94%, crude fat content of 1.61 to 1.29%, crude protein content of 3.50 to 4.66%, crude ash content of 0.68 to 0.82% and dietary fiber content of 0.12 to 1.46%. Ju-bak powder added with jeung-pyun had a pH level from 4.86 to 4.39. As ju-bak content increased, the pH decreased significantly. Color L value were 78.82 to 68.67. As ju-bak content increased, the Color L value content decreased significantly; a value ranged from -1.89 to 0.69 and b value from 2.99 to 14.25. As ju-bak content increased, the color content significantly increased. As ju-bak content increased, the volume significantly decreased (ranged from 42.50 to 30.00 mL), hardness, gumminess and chewiness significantly increased, and cohesiveness significantly decreased. From SEM, as ju-bak content increased, the pores merged and collapsed, whereas the number of pores decreased and pore size became larger. Sensory evaluation of color, flavor, taste, texture, appearance, cell uniformity and overall acceptability for various levels of ju-bak powder showed that 10% had the highest acceptability. Therefore, 10% ju-bak power added with jeung-pyun has both high antioxidant capacity and sensory acceptability.

• 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.19 no.4
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• pp.504-510
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• 2003

To optimize the preparation process of Jeung-Pyun, an experiment was derived, using a central composite design, to fmd the optimal mixing conditions. The addition of Paecilomyces japonica powder, the volume of Tak-Ju and the second fermentation time were independent variables, with the pH, volume, color, sensory and texture properties of the Jeung-Pyun selected as response variables. As the Paecilomyces japonica powder and fermentation time were increased, the b values and volume after the second fermentation also increased. The color of the Jeung-Pyun became deeper with increases in the Paecilomyces japonica powder and fermentation time, and was deepest on the addition of 30% Tak-Ju. The pH increased with increasing fermentation time of the Jeung-Pyun, and on the addition of 3% Paecilomyces japonica rapidly increased more than with the other groups. The optimal mixing conditions for the best quality Jeung-Pyun, with restricted conditions above a b value of 3, a color intensity above 3, and a volume of 40mQ and a pH of 4.02-4.04 after the second fermentation, were 4.0%, 20% and 45 mins for the Paecilomyces japonica powder, Tak-Ju and second fermentation time, respectively.

• Journal of the East Asian Society of Dietary Life
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• v.15 no.6
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• pp.766-772
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• 2005

The purpose of this study is to find out the optimal mixing ratios of Mal-Cha for the preparation of Jeung-Pyun through sensory and mechanical tests. The proximate composition of Mal-Cha were $5.46\pm0.15\%$ of moisture, $4.43\pm0.11\%$ of total nitrogen, $7.52\pm0.21\%$ of crude lipid, $8.74\%$ of crude fiber, $8.51\pm0.09\%$ of ash. Overall quality of Jeung-Pyun with $1.5\%$ Mal-Cha was the worst compare with 0, 0.5 and $1.0\%$ ones(p<0.05). Especially, $1.0\%$ Mal-Cha Jeung-Pyun showed the best overall quality. But the sweetness, sourness, flavor, hardness, and moistnes were not significantly different among all the treatments. Acceptabilities of 0.5 and $1.0\%$ Mal-Cha Jeung-Pyuns were not significantly different from that of the control in their sensory and mechanical qualities. Total color difference increased with the amount of Mal-Cha significantly(p<0.001).

• 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.

• Korean journal of food and cookery science
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• v.29 no.6
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• pp.749-760
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• 2013

The purpose of this study was to examine the characteristics of quality and anti-oxidation of brown rice Jeung-pyun dough containing different amounts of acorn flour. The acorn flour added brown rice Jeung-pyun's specific volume increased at the second week of storage to 1.33~1.55mL/g, while the fourth week decreased to 1.57~1.64 mL/g. The pH of Jeung-pyun (5.19~5.36), in general, was higher than dough (5.14~5.22). The gelatinization was decreased to 1.69~2.24 range as storage period increased. Especially, the 9% acorn flour added group's gelatinization was delayed than other groups. The mechanical texture of hardness as the amount of acorn flour increased, while adhesiveness, cohesiveness and springiness reduced. The sensory evaluation results show that 9% acorn flour added group had generally high marks in appropriateness.