• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.8
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• pp.1025-1030
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• 2006

In other to develop new functional doenjangs, two types of the isolated nuruk doenjangs were prepared with protease and amylase-producing Aspergillus oryzae D-2 and antihyperlipidemia Bacillus subtilis LK-12 and then changes of its quality and physiological functionalities were investigated during 2 months of fermentation and compared with those of the commercial nuruk doenjangs made by commercial Aspergillus oryzae and antihyperlipidemia Bacillus subtilis LK-12. ${\alpha}-Amylase$ activity of the isolated nuruk doenjangs during fermentation were decreased slightly, whereas proteases activities were increased significantly to $1.8{\sim}2.8$ Unit per mL after 1 month of fermentation. These ${\alpha}-amylase$ activities and proteases activities were similar with those of the commercial nuruk doenjangs. Amino-nitrogen content and reducing sugar content of the doenjangs after 2 months of fermentation were approximate $1.63{\sim}1.72\;mg%$ and $0.77{\sim}0.81%$, respectively. Antihypertensive angiotensin-Ⅰ converting enzyme inhibitory activities of the isolated nuruk doenjangs were slightly decreased from $85.6{\sim}87.2%$ to $84.0{\sim}85.1%$ after 2 months of fermentation and the commercial nuruk doenjangs were also significantly decreased from $85.7{\sim}88.0%$ to $69.1{\sim}79.7%$, lower than the isolated nuruk doenjangs. Fibrinolytic activity and HMG-CoA reductase inhibitory activity of the isolated nuruk doenjangs were very low and it were also similar with those of the commercial nuruk doenjangs. Antioxidant activity of the isolated nuruk doenjangs were showed $17{\sim}22%$, lower than that of the commercial nuruk doenjangs $(22{\sim}26%)$.

• Food Science and Preservation
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• v.18 no.6
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• pp.853-858
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• 2011

Soybean-based food items have been developed as common fermented side dish sauces in South Korea, Japan, and China. Each of these countries, however, has its own fermentation method, including a microorganism-based fermentation process, the mixing of ingredients, the fermentation process, and the mixing of starch. The purpose of this study was to determine the quality characteristics of the commercial product. Fourteen kinds of rice soybean paste (Korea, 2 Japan, 12) were prepared, and their physiochemical properties (ammonium nitrogen, amino nitrogen, amylase, protease, and reducing-sugar contents) were analyzed. JRD-1 was found to contain the highest amount of amino-type nitrogen (426.45 mg%) while KRD-2 showed 316.10 mg%. For the protease activities, the following results were obtained: JRD-9, 695.10 unit/g JRD-11, 671.45 unit/g and JRD-5, 665.03 unit/g. As for the amylase activities, the results that were obtained were JRD-7, 53.65 unit/g JRD-8, 50.71 unit/g KRD-1, 46.52 unit/g JRD-1, 46.29 unit/g and JRD-11, 33.61 unit/g. This research provided information for the quality characteristics of commercial rice soybean paste.

• Korean Journal of Microbiology
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• v.48 no.2
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• pp.147-155
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• 2012

To improve of the quality of Korea traditional wheat-rice wine (makgeolli) production, we used a rice fermentation starter (rice nuruk) made by inoculation of Rhizopus oryzae CCS01 which was isolated and selected from commercial nuruk. Amylase activity of a rice nuruk was 1.8-2.4 times higher than those of commercial nuruks. The best acceptability of wheat-rice wine in a sensory test was observed at 4 : 6 ratio of wheat-rice mash at experimental condition. During the fermentation period, pH of wheat-rice makgeolli made with a rice nuruk was higher compared to those made with commercial nuruks such as Sanseong, Jinju, and Songhak. Acidity of makgeolli mash was lower in case of using a rice nuruk and birx and alcohol production were higher compared to those of makgeolli mash using commercial nuruks. Highest alcohol production was observed at makgeolli mash using a rice nuruk and 12% of alcohol was produced at fermentation end. These results suggest that production of a new type of wheat-rice makgeolli using a rice nuruk was possible.

• Food Science and Preservation
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• v.21 no.4
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• pp.573-580
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• 2014

The enzymatic activity of Nuruk and the quality properties of Yakju were investigated according to different fungi. The fungi that were used in this study were Aspergillus kawachii KCCM 32819, Aspergillus niger KCCM 32005, Rhizopus japonicus KCCM 11604, Rhizopus oryzae KCCM 11272, Rhizopus oryzae KCCM 11273, Rhizopus oryzae KCCM 11276, and Mucor rouxii KCCM 60148. The study results are as follows. The saccharogenic power of Rhizopus oryzae KCCM 11272 Nuruk was the highest (3,647.72 SP/g) among all the samples. The ${\alpha}$-amylase production and protease activities were highest (3.76 DU and 4.7 tyrosine mg/min, respectively) in the Rhizopus japonicus KCCM 11604 Nuruk. The pH levels of the Yakju made with commercial Nuruk and Rhizopus japonicus KCCM 11604 Nuruk were 4.14 and 4.07, respectively. The total titratable acid content of the Yakju made with Rhizopus oryzae KCCM 11273 Nuruk was the highest (0.56%) among all the samples. Rhizopus japonicus KCCM 11604 and Rhizopus oryzae KCCM 11272 had the highest ethanol yields (15.18% and 15.10%, respectively). In the sensory evaluation carried out in this study, the panel preferred the Yakju made with Rhizopus japonicus KCCM 11604 Nuruk. Overall, however, the panel did not like the Yakju made with Aspergillus niger KCCM 32005 Nuruk.

• Food Engineering Progress
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• v.13 no.3
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• pp.176-182
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• 2009

This study was carried out to analyse the physicochemical characteristics of soybean pastes with the sword beans and general soybean pastes. There was no difference in contents of general component (moisture contents, crude ash, crude fiber, crude fat) among the soybean pastes, but contents of crude protein was higher in J1, J2 compared to the others. Amylase activity was higher in J3, J4 adding the rice, and protease activity was higher in J1, J2 that has higher soybean contents than the others. Reducing sugar contents was higher in J3, J4 that has high amlyase activity with value of 8.53${\pm}$0.45% and 8.36${\pm}$1.05%, and amino-type nitrogen contents was higher in commercial soybean paste K5, K6 than other soybean pastes with value of 668.34${\pm}$4.11 mg% and 642.64${\pm}$2.05 mg% respectively.

• Microbiology and Biotechnology Letters
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• v.26 no.2
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• pp.187-194
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• 1998

Glycosides were synthesized using transglycosylation reaction of amylase in water system. Starch as a glycosyl donor and benzylalcohol as an acceptor were selected as substrates of transglycosylation reaction. Among tested 9 commercial amylase, amyloglucosidase from Rhizopus sp. had high activity for transglycosylation from starch. The glycoside synthesized in water phase by amyloglucosidase was identified as benzylalcohol-${alpha}$-glucoside (BG) of which one molecule of benzylalcohol was bound to 1-OH of glucose. The transglycosylation reaction by amyloglucosidase were carried out in reaction system containing 50 mg starch, 50 mg benzylalcohol, and 10 units enzyme in pH 5.0 at 45$^{\circ}C$. The synthesized BG was hydrolyzed by ${alpha}$-glucosidase to produce glucose and benzylalcohol.

• Microbiology and Biotechnology Letters
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• v.15 no.6
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• pp.408-413
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• 1987

Microorganisms capable of degrading the raw naked barley were isolated from soil, and the amylase productivity of each strain was examined on plate contained 2％ raw naked barley. Of the fungi and actinomycetes tested, 71 strains were subjected to subsequent testing for amylase production, and 4 strains were selected as potent amylase producers. Among them, Strain No. 281 produced the most potent raw naked barley saccharifying enzyme, and was identified as genus Rhizopus from morphological and physiological studies. The ratio of raw starch saccharifying activity (RDA) of the crude enzyme derived from the Rhizopus sp. No. 281 was showed 2-3 fold higher than that of commercial enzyme when the raw naked barley was used as the substrate. In the case of uncooked alcohol fermentation using Rhizopus sp. No. 281 glucoamylase preparation, the alcohol yield of the broth was 2％ higher than that of the commercial enzyme.

• Journal of Ginseng Research
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• v.31 no.2
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• pp.102-108
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• 2007

The goal of this study was to develop a highly valuable Korean traditional ginseng wine containing various bioactive compounds with good acceptability. The effect of some medicinal plants on the quality and physiological functionality of Korean traditional ginseng wine were investigated. Advanced traditional ginseng wine (AG wine) prepared by addition of 0.5% each Pleuropterus multflorus and Pueraria lobata into the rice mash containing 1% ginseng, 0.4% Fermivin(commercial alcohol fermentation yeast) and Koji (2:1 mixture of nuruk and amylase containing 36 Saccharogenic power per g) showed the highest acceptability and ethanol content (16.8%). Changes of functionalities of the AG wine during fermentation at $25^{\circ}C$ for 30 days were investigated. The highest antihypertensive angiotensin I-converting enzyme inhibitory activity (78.9%) and total acceptability of the AG wine were shown after fermentation at $25^{\circ}C$ for 20 days. However, antioxidant activity, SOD-like activity and fibrinolytic activity of the AG wines were not detected or very low. HMG-CoA reductase inhibitory activity of the AG wine was also shown to be 8.2% and 9.2% after fermentation for 15 days and 20 days, respectively.

• Applied Biological Chemistry
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• v.28 no.1
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• pp.28-35
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• 1985

Potato tubers treated at $4^{\circ}C$ for 4 weeks were irradiated with a dose of 0.12 kGy from $^{60}Co$ source and stored at $20^{\circ}C,\;70{\sim}90%$ humidity for 5 weeks. Changes of ${\alpha}-amylase$, peroxidase, indole acetic acid oxidase, indole acetic acid synthesizing enzyme activities were determined. In addition, treatment of gibberellin or indole acetic acid to tubers irradiated were carried out to examine reversal of sprout-inhibition of tubers irradiated. Results are as follows; 1. Irradiation by ${\gamma}-ray$ at 0. 12 kGy dose inactivated easily the enzyme activities in vitro. $D_{37}$ values obtained were 0.94, 0.36 kGy for ${\alpha}-amylase$ and peroxidase, respectively 2. Complete inhibition of the toter sprouting was resulted by the irradiation of tubers with a dose of 0.12 kGy. 3. The indole acetic acid oxidase activity increased 2 times immediately after irradiation. Meanwhile, indole acetic acid synthesizing activity decreased about $50{\sim}75%$ for 5-week storage in irradiated potatoes, whereas the activity increased about 3.5 times along with sprouting in non-irradiated tubers. 4. In morphological aspects, deformed buds with necrosis in the meristmatic tissue were developed in irradiated tubers. Treatment of gibberellin or indole acetic acid at the concentration of 100 or 20 ppm to the irradiated tubers reversed the sprout-inhibition partially. Nevertheless, the deformed buds remained without change.

• The Korean Journal of Food And Nutrition
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• v.8 no.3
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• pp.165-171
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• 1995

Sikhye is a traditional sweet rice drink in Korea by $\beta$-amylase's saccharifing action. Sikhye has great potentiality for commercial beverage because of It's characteristic taste and flavors. But, the chemical compositions and production methods of Sikhye are little known. The total amount of carbohydrate of sixteen Sikhye selected in Korean market was 11~15%. The reducing sugar by the Somogyi-Nelson's method was measured 0.4~2% as maltose, which has little influence on the sweetness of Sikhye. While sucrose content was about 10% by the TLC and Seliwanoff analysis. It means that carbohydrate in Sikhye was almost sucrose. Furthermore the most of Sikhye has brown color and turbidity. To improve the quality of Korean Sikhye, it is necessary to increase the production of maltose and to reduce brown color and turbidity, without adding sucrose.