• The Korean Journal of Mycology
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• v.41 no.1
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• pp.33-37
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• 2013

To develop the functional pear fruitlet product, we prepared fermented pear fruitlet product (FPFP) from mixed fermentation of Saccharomyces cerevisiae, Kluyveromyces fragilis and Lactobacillus plantarum. Then, we investigated their several physiological functionalities. Among several physiological functionalities, antihypertensive angiotensin I-converting enzyme (ACE) inhibitory activity of the FPFP was the highest of 87.4% and its antioxidant activity was also showed 69.6%. FPFP from mixed fermentation by yeasts and Lactobacillus plantarum after thawing of frozen pear at $20^{\circ}C$ showed higher physiological functionalities than those of single fermentation by Saccharomyces cerevisiae or Bacillus subtilis after $40^{\circ}C$ of thawing.

• Korean Journal of Food Science and Technology
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• v.54 no.3
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• pp.343-350
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• 2022

In this article, we report a case study on the cause of abnormal fermentation of Takju based on a microbial community analysis of wheat-based Nuruk and Takju using next-generation sequencing. The microbial community showed notable changes during alcoholic fermentation. Members of the genera Aspergillus and Staphylococcus were dominant in Nuruk, whereas Saccharomyces, Pediococcus, Bacillus, Lactobacillus, and Enterobacter were predominant during Takju fermentation. In particular, members of the Enterobacter and Bacillus genera that were present were identified as the opportunistic pathogens B. wiedmannii and E. cloacae. The relative abundance of two species increased in Mitsul-3, wherein the concentration of organic acid rapidly decreased, and in Deotsul-1, in which raw materials were added. Furthermore, the relative abundance of lactic acid bacteria (LAB) in both the Nuruk and Takju was very low. Therefore, this result showed that the abnormal proliferation of E. cloacae and B. wiedmannii in Takju was due to the absence of LAB.

• Microbiology and Biotechnology Letters
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• v.4 no.4
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• pp.152-158
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• 1976

Cultivation condition of yeast on the utilization of fermentable substrate from the cellulosic wastes such as rice hull, rice straw and corn starch cake was investigated. The results obtained were summarized as follows；1. Corn starch cake was respectively added to rice hull and rice straw in order to increase sugar concentration in the hydrolyzate, and then hydrolyzed. As the result, concentration of sugar in hydrolyzed solution of rice hull was 9.12％, in that of rice straw was 7.98％. 2. It was found that calcium carbonate as a neutralizer was the most effective to prepare the culture broth of yeast. 3. An optimal growth of Hansenula subpelliculosa GFY-2 was observed in the medium prepared by adding 0.3％ of ammonium sulfate, 0.4％ of potassium phosphate dibasic, 0.02％ of magnesium sulfate, sodium chloride and calcium chloride to hydrolyaed sugar solution, respectively. 4. Hansenula subpellicuiosa GFY-2 cultured in the substrate solution which of rice hull and rice straw added to corn starch cake was assimilated more than 90％ of sugar in the hydrolyzate within 48 hours. The yeast cells yielded in rice hull was 46.5％, and that of rice straw 45.4％ to utilized sugars.

• Applied Biological Chemistry
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• v.46 no.3
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• pp.229-234
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• 2003

The traditional kochujang supplemented with mushrooms (Pleurotus ostreatus and Lentinus edodes) was prepared, and changes in quality characteristics during fermentation at ambient temperature were investigated. The moisture content of kochujang increased by addition of mushroom. The titratable acidity of mushroom-added kochujang was gradually increased during fermentation. Ethanol contents of mushroom-added kochujang decreased with the addition of oyster mushroom, but increased with the addition of oak mushroom. The amino-nitrogen contents increased gradually during fermentation, resulting in significantly higher contents of 9% mushroom-added kochujang than others. The a value of kochujang decreased greatly during fermentation, but L, a and b values showed significantly higher than the control. The growth of bacteria in kochujang was delayed by the addition of mushrooms. Bacterial and yeast counts at the end of fermentation were not influenced by the addition of mushrooms. Sensory evaluation test revealed that color and flavour of kochujang were improved by the addition of mushrooms, and higher score was obtained from the addition of oyster mushroom compared to oak mushroom.

• Culinary science and hospitality research
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• v.21 no.1
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• pp.267-280
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• 2015

This study was carried out to evaluate the quality characteristics of Takju, Yakju, Spirit made by various cereal Nuruks which were made by Jokuk(whole wheat), Bunkuk(wheat flour), Maekkuk(whole barley). pH, Brix, cell number of yeast, alcohol content, flavors, organic acid, and sensory evaluation of brews were employed to analyze current study. Results showed that pH value of brews during fermentation decreased, while Brix value increased. In addition, alcohol contents increased up to 11 day's fermentation, but there were no significant differences among Jokuk, Bunkuk and Maekkuk(p<0.05). Cell numbers of yeast dramatically increased up to 5 day's fermentation, and then decreased. After 13 day's fermentation cell numbers of yeast were similar among Jokuk, Bunkuk and Maekkuk. In terms of analysis of flavor components, acetone and n-amyl alcohol were not detected in all brews, however fusel oil level was 494.65 mg/L in Maekkuk, and 525.4 mg/L in Bunkuk. Lactic acid showed the highest level in organic acid analysis. Furthermore, Jokuk and Maekkuk showed highest score in Takju, Maekkuk showed highest score in Yakju in sensory evaluation, although Jokuk, Bunkuk, and Maekkuk revealed similar score in spirit.

• Korean journal of food and cookery science
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• v.17 no.3
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• pp.224-228
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• 2001

We studied the effects that the addition of Kimchi has on microbiological properties of fermented sausages as we observed pH and microbiological changes of Kimchi-added fermented sausage by aging period. The pH figure of sausages added with commercial starter culture was 5.69 at the beginning stage and declined gradually to 5.01. The more Kimchi is added, the lower pH figure goes. Sausages with 10% and 20% of fresh Kimchi, and 2% and 4% of powdered Kimchi added, showed about pH 5.4 at the early stage and down to pH 4.87 as they are stored longer. In terms of microbiological changes, sausages mixed with starter culture showed 10$\^$7/cfu/g level in the number of total bacteria, lactic acid bacteria, yeast and fungi, lower than Kimchi-added sausages. However, the figure soared sharply to 10$\^$10/cfu/g during the aging period. Kimchi-added sausages recorded 10$\^$9/cfu/g, slightly high during the eurly aging stage, in the number of total bacteria, lactic acid bacteria, yeast and fungi, while showing a gradual increase up to 10$\^$10/cfu/g towards the end of aging period and became microbiologically stabilized.

• Korean Journal of Food Science and Technology
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• v.39 no.3
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• pp.304-308
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• 2007

This research was conducted to investigate the changes in quality characteristics of meju made with 24-hour germinated soybeans according to fermentation time. The study confirmed that the amino nitrogen content immediately after soaking was 15.5 mg%, and the content rapidly increased in the beginning of the germination process and continued to increase to 312.9 mg% by 48 hours of fermentation. The number of fungi in the whole soybean meju made with 24-hour germinated soybeans was higher than the numbers of bacteria and yeast since the Aspergillus oryzae was inoculated artificially. The content of organic acids, in which the amount of citric acid was highest followed by tartaric acid and malic acid, increased with the fermentation process. The level of free amino acids in the whole soybean meju made from the 24-hour germinated soybeans increased rapidly with fermentation. The free amino acid content after 48 hours of fermentation (2,513.5 mg%) was 5.7 times higher than the content of the soaked germinated soybeans. The content of glutamic acid was highest followed by aspartic acid, lysine, leucine, and proline. The ratio of glutamic acid to the total free amino acids at 48 hours fermentation was 21.2% for the whole soybean meju. It was confirmed that the total isoflavone content, in which the content of genistein was highest followed by daidzein and glycitein, increased at the beginning of the fermentation process, but did not change thereafter.

• Microbiology and Biotechnology Letters
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• v.26 no.1
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• pp.50-54
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• 1998

Ethyl caproate is one of the important flavor compounds produced during the brewing of rice wine. The rice wine yeast and koji were reported to produce the esterases which synthesize and also hydrolyze ethyl caproate. From the results of monitoring the esterase activities of rice wine yeast and koji, their roles for producing ethyl caproate during brewing were postulated. In case of rice wine yeast, the production of esterase synthesizing ethyl caproate was influenced by the substrate, caproate but that of esterase hydrolyzing ethyl caproate was promoted by ethyl caproate but inhibited by caproate. The production of esterases of koji were not influenced by the substrates for ethyl caproate production but influenced by the growth of koji. The maximum concentration of ethyl caproate produced by rice wine yeast was 0.4 ppm in this research but the production of ethyl caproate by koji was not detected under our experimental conditions. Considering the results of this research, ethyl caproate is not produced by the esterases of koji during brewing but produced by the esterases of rice wine yeast. The growth of rice wine yeast represses that of koji because of the high concentration of ethanol produced by rice wine yeast. The esterases of rice wine yeast may decide the production of ethyl caproate during brewing.

• Food Science and Preservation
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• v.10 no.3
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• pp.326-332
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• 2003

Deep seawater is pumped up about 200 m water depth, which has characteristics of rich nutrients, low temperature and cleanness. This study was performed to investigate the effect of deep seawater and deep seawater salt on the yeast growth of fermented bread. The rate of increase in volume of groups added with deep seawater and deep seawater salt was higher than that of groups added with distilled water. The pore pattern of groups added with deep seawater was more regular than that of groups added with distilled water. In sensory property, the bread added with distilled water and deep seawater salt has the highest score (6.56) in overall acceptability.

• Food Science and Preservation
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• v.30 no.4
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• pp.691-702
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• 2023

This study aimed to develop high value-added mulberry (Morus alba) vinegar by fermenting mulberry with yeast and acetic acid bacteria, for using it in various foods. To select the optimal strain for mulberry fermentation, different strains were tested and Saccharomyces cerevisiae SRCM101756 and Acetobacter pasteurianus SRCM102419, exhibiting excellent alcohol and acetic acid production ability during mulberry fermentation, were selected for fermentation. Mulberry vinegar was prepared using mulberry wine and the selected acetic acid bacteria, and the physicochemical properties and physiological effects were measured. The pH was 2.98 and total acidity was 4.70% by day 9 of fermentation, establishing the possibility of developing them into vinegars for industrial use. The angiotensin-glucosidase inhibition activity of mulberry vinegar increased from 13.22% to 19.19% in the 100-fold dilution, and from 42.35% to 46.11% in the 50-fold dilution, from before fermentation to after fermentation, respectively. The angiotensin-converting enzyme inhibition activity of mulberry vinegar was found to significantly increase from 44.82% before fermentation to 63.88% after fermentation in the 25-fold dilution. Moreover, a significant increase in pancreatic lipase inhibition activity after fermentation was observed. Thus, mulberry vinegar can be used as a functional material in vinegar and other foods.