• Journal of Applied Biological Chemistry
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• v.59 no.1
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• pp.57-62
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• 2016

In this study, we optimized fermentation conditions for the solid state fermentation of rice bran with Monascus pilosus KCCM60084, and the antioxidant activities were investigated. Optimal fermentation conditions were determined by the production of Monacolin K, a functional secondary metabolites with cholesterol lowering activity. The highest Monacolin K production were 2.88 mg/g observed on day 10 with 45% moisture content in the substrate when inoculated with 5% inoculum (w/w). Reducing power, iron chelating activity and $ABTS^+$ radical scavenging activity were significantly enhanced after fermentation by 60, 80, and 38% respectively. Furthermore, the content of total flavonoid were found to be increased by 4.58 fold. Based on these results, Monascus-fermented rice bran showed strong possibility to be used as a natural antioxidant agent due to its enhanced antioxidant activity.

• Food Science and Preservation
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• v.5 no.4
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• pp.374-379
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• 1998

A vinegar was prepared from uncleaned rice by two step fermentation, alcohol fermentation followed by acetic acid fermentation. The contents of alcohol reached to 10.8% during the alcohol fermentation of uncleaned rice with nuruk, and acidity reached to 5.78% during the acetic acid fermentation. Acidity and pH of vinegar of two step fermentation were higher than those of commercial vinegars. 'L' value(Light) of the vinegar was lower, 'a' and 'b' value were higher than those of commercial vinegars. The contents of acetic acid, malic acid, citirc acid and tartaric acid were hish in organic acid of vinegars. The content of each ofganic acid in vinegars was remarkably different. The content of free amino acids was 2199.7${\mu}\ell$/ml in the vinegar produced by two step fermentation which is higher than that of others.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.12
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• pp.1693-1700
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• 2012

In this study we examined the antioxidant activity and fermentation characteristics of black rice wine. The antioxidant activity of black rice wine was higher than the control, and DPPH radical scavenging activity showed a correlation with the anthocyanin content of rice wine. The pH remarkably decreased until 3 days of fermentation, and the gradually decreased. The reducing sugar and free sugar content reached a maximum at 1 day of fermentation due to enzyme activity. The amount of organic acids, especially lactic acid, increased during the fermentation period. Lactic acid bacteria and yeast count increased with time and amount of black rice. The L color value increased during fermentation regardless of treatments, and the a color value increased with ratio of black rice due to anthocyanin. For this reason, color was given a high score in black rice wine. But overall preference was high in rice wine made with less than 20% of black rice.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.6
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• pp.808-816
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• 2022

This study was conducted with a view toward enhancing the industrial utilization of a male sailfin sandfish Arctoscopus japonicus based on its application in the preparation of Sik-hae, a Korean traditional fermented fishery product prepared using hard-boiled rice and enzymatic malt sprouts. As an alternative to rice and malt sprouts, we evaluated the utility of rice Koji for Sik-hae fermentation by investigating the physicochemical changes that occur during fermentation. The sailfin sand fish Sik-hae fermented with 10% or 20% rice Koji was found to show similar fermentation characteristics to the control fermentation with 20% hard-boiled rice and 4% malt sprouts, with respect to acid production, texture profile, and the softening of bones during the entire fermentation period. In particular, compared with the control, the addition of 10% rice Koji reduced the dehydration of Sik-hae and increased the content of free amino acids, which contributed to preventing a marked reduction in pH during fermentation. Accordingly, 10% rice Koji is proposed as a viable alternative enzymatic agent for the preparation of Sik-hae, which can contribute enhancing the desired properties of this traditional food product.

• Korean Journal of Agricultural Science
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• v.48 no.2
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• pp.273-281
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• 2021

These days, different types of yogurt are being manufactured by adding various starters and functional ingredients for health. The purpose of this study was to prepare yogurt added with rice followed by fermentation with two types of starters and to examine its attributes. Ten percent of skim milk powder and 0, 2.5, 5.0, 7.5, or 10% rice were mixed in water (w/v) and then inoculated with two types of starter: 1) Type A, Streptococcus thermophiles and Lactobacillus delbrueckii ssp. bulgaricus as starter; and 2) Type B, Streptococcus thermophiles, Lactobacillus acidophilus, and Bifidobacteium animalis ssp. lactis as starter. The pH of B type yogurt was lower (p < 0.05) than that of A type yogurt from 6 hours to 14 hours after fermentation. The number of microorganisms in all fermented milk showed maximum increases at 2 and 6 hours of fermentation (p < 0.05). The number of microorganisms in fermented milk peaked at 6 hours after fermentation and maintained this level thereafter. There was no effect of rice addition on microbial growth or acidity of the fermented milk. Sensory attributes of yogurt samples with and without added rice were not significantly different. This experiment showed that the production efficiency of yogurt with added rice was not different when two different types of starters were used to manufacture yogurt.

• Microbiology and Biotechnology Letters
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• v.16 no.3
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• pp.213-218
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• 1988

Studies were made to optimize the simultaneous saccharification and fermentation (SSF) of rice straw to produce butanol using Clostridium acetobutylicum KCTC 1037 and a cellulolytic enzyme preparation from Trichoderma viride. The fermentation was inhibited when the liquid enzyme preparation from Novo was used, whilst a successful fermentation was achieved in the SSF using the enzyme manufactured by Pacific Chemical Co. The minimum cellulase concentration for the successful fermentation of pure cellulose was found to be 4 IU/g of substrate used. Alkaline treatment was better method for the fermentation of rice straw by the system. SSF using 25％ alkaline treated rice straw produced 150 mM butanol, 90 mM acetone. On the other hand, fermentation of ball milled rice straw was mainly acidogenic producing 98 mM acetate and 64 mM butyrate with less than 20 mM butanol. These results show that rice straw contains (a) specific inhibitor(s) for solventogenesis which is destroyed or soluble in alkali.

• Korean Journal of Food Science and Technology
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• v.36 no.4
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• pp.616-623
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• 2004

Fermentation characteristics of rice-grape wine with different mixing ratios of rice and grape, rice one vs. grape five (Exp.1), rice two vs. grape five (Exp.2), rice five vs. grape five (Exp.3), and rice five and grape two (Exp.4), were investigated. Final alcohol contents of Exp.4, Exp.3, Exp.2, and Exp.1 were 18.4, 16.0, 14.9, and 12.9%, respectively. Final alcohol content increased with increasing amount of rice. Acidity of four experiments ranged pH 3.4-3.92, and total acidity was 0.52-0.74%. Exp.4, Exp.3, Exp.2, and Exp.1 gave a values of 8.76, 12.77, 12.88, and 23.96, respectively. When different mixing methods were applied to Exp.1, the resulting final alcohol contents of Exp.6 (grape musts periodically added after rice fermentation), Exp.7 (rice and grape simultaneously added and fermented), and Exp.8 (rice added after grape must fermentation) were 2.3-3.2% Bower than that of Exp.1 (grape must added after rice fermentation), and total acidity was 0.72-0.74%. Sensory evaluation comparing conventional red wine and rice-grape wine of Exp.1 showed rice-grape wine was preferred in taste.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.8
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• pp.492-501
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• 2016

This study was conducted to investigate the physiochemical characteristics of Cheongju prepared using different types of rice (rice and glutinous rice) according to addition rate of Nuruk during low temperature fermentation. The characteristics of Cheongju prepared using three different temperatures ($10^{\circ}C$, $18^{\circ}C$, $25^{\circ}C$) were compared. After fermentation for 30-50 days, the pH of mash prepared at lower temperature was lower, as was that of mash made from rice relative to that prepared using glutinous rice. The total acidity was formed at lower temperature and generated in mashing prepared by glutinous rice. The organic acid content of mash made from rice at $18^{\circ}C$ was lowest, while that of mash prepared from glutinous rice was lowest at $10^{\circ}C$. The fermentation speed was lowest at $10^{\circ}C$; however, low temperature fermentation resulted in the highest alcohol content. The mash prepared from glutinous rice showed faster fermentation than that made from rice. In addition, the pH was lower when lower levels of Nuruk were added and higher in mash made from glutinous rice than that prepared from rice. The lower addition rate of Nuruk also showed a lower sugar content and final alcohol content. The levels of citric acid and lactic acid were higher, while those of succinic acid, acetic acid, and ethyl acetate were lower when lower levels of Nuruk were added. The mash prepared from glutinous rice showed a higher alcohol content than that made from rice.

• Journal of the East Asian Society of Dietary Life
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• v.8 no.2
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• pp.162-173
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• 1998

The effect of soybean addition to the preparation of Jeung-Pyun(Korean fermented rice cake) and the fermentational characteristics of Jeung-Pyun dough were determined. Jeung-Pyun dough composed of rice 100g, soybean 20g, water 40g, salt 0.8g, sugar 15g and Tak-ju 30g was fermented for up to 20hours. the numbers of total microbes, yeasts and lactic acid bacteria in the dough during fermen-tation increased rapidly during 5 hours of fermentation, but Leuconostoc mesenteroides during 7 hours of fermentation, Generally, there were many more microbes in the Jeung-Pyun dough with soybeans than in the Jeung-Pyun dough with rice. The volume of 7 hour fermented Jeung-Pyun was most massive, especially in the soybean added Jeung-Pyun. 1% dextran-added rice Jeung-Pyun, the volume of steamed cake was increased more than that of rice Jeung-Pyun, but is was not as bulky as in the soybean-added cake. In the sensory evaluation of the test cake products, the 7 hour fermented cake was preferred by nost. As for instrumental characteristics, the 7 hour feremented Jeung-Pyun showed the lowest values for hardness and elasticity, brittleness and chewiness. The rice Jeung-Pyun showed were stored at 2$0^{\circ}C$ the hardness, brittleness and cohesiveness of rice Jeung-Pyun were respectively increased rapidly after 5 days of storage. The cohesiveness, elasticity, brittleness, chewiness, gumminess of both rice Jeung-Pyun and soybean-added Jeung-Pyun were decreased with storage time.

• Mycobiology
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• v.32 no.4
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• pp.170-172
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• 2004

The efficiency of acid, enzyme and microbial pretreatment of rice bran was compared based on the content of cellulose, hemicellulose, reducing sugars and xylose in the substrate. An isolate of Aspergillus niger or a strain of Trichoderma viride(MTCC 800) was employed for microbial pretreatment of rice bran in solid state. Acid pretreatment resulted in the highest amount of reducing sugars followed by enzyme and microbial pretreatment. A. niger showed a higher rate of hydrolysis than T. viride. The rice bran hydrolysate obtained from the different methods was subsequently fermented to ethanol either by Zymomonas mobilis(NCIM 806) or by Pichia stipitis(NCIM 3497). P. stipitis fermentation resulted in higher ethanol(37% higher) and biomass production($76{\sim}83%$ higher) than those of Z. mobilis. Maximum ethanol production resulted at 12h in Zymomonas fermentation, while in Pichia fermentation, it was observed at 60h. Microbial pretreatment of rice bran by A. niger followed by fermentation employing P. stipitis was more efficient but slower than the other microbial pretreatment and fermentation.