• Food Science and Preservation
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• v.9 no.2
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• pp.179-183
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• 2002

This study was carried out to set up alcohol fermentation condition for uncooked corn. Response surface methodology(RSM) was applied to optimize and monitor the alcohol fermentation condition with uncooked corn. The optimal yeast strain for fermentation of uncooked corn was Saccharomyces cerevisiae GRJ. The polynomial equation for alcohol contents, brix, pH and total acidity showed 0.8852, 0.9202, 0.8806 and 0.9940 of R$^2$, respectively. The optimal rendition for maximum alcohol contents were 0.18%(w/w) of enzyme concentration and 180%(v/w) of added water content. Predicted values at optimum alcohol fermentation condition agreed with experimental value.

• Food Science and Preservation
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• v.8 no.4
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• pp.412-418
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• 2001

This study was carried out to set up alcohol fermentation condition for uncooked brown rice. Response surface methodology(RSM) was applied to optimize and monitor of the alcohol fermentation condition with uncooked brown rice. The optimal yeast strain for fermentation of uncooked brown rice was S. cerevisiae GRJ. The polynomial equation for alcohol contents, brix pH and total acditiy showed 0.8828, 0.8409, 0.9431 and 0.9280 of R$^2$, respectively. Optimum range of uncooked alcohol fermentation for maximum alcohol contents were 0.34%(w/w) of enzyme concentration and 350%(w/w) of added water content, respectively. Predicted values at optimum alcohol fermentation condition agreed with experimental values.

• Microbiology and Biotechnology Letters
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• v.18 no.5
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• pp.506-510
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• 1990

The Takju brewing of raw rice starch was carried out by the simultaneous saccharification- fermentation using Rhizopus sp. koji and yeast, and compared with the Takju mash brewed by the conventional method. Rhitopus koji was prepared with uncooked rice for Takju brewing without cooking of rice starch. Alcohol concentration of Takju mash brewed with uncooked rice was slightly higher of 1.8% than that with cooked one. Amino acid contents was almost double and fuse1 oil contents was lower in uncooked brewing. The Takju mash prepared after fermentation without cooking of rice had a characteristic odor of raw material and a good quality of taste.

• Journal of Microbiology and Biotechnology
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• v.19 no.10
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• pp.1161-1168
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• 2009

Ethanol production by the simultaneous saccharification and fermentation (SSF) of low-value rice wine cake (RWC) without cooking was investigated. RWC is the filtered solid waste of fermented rice wine mash and contains 53% raw starch. For the SSF, the RWC slurry was mixed with the raw-starch-digesting enzyme of Rhizopus sp. and yeast, where the yeast strain was selected from 300 strains and identified as Saccharomyces cerevisiae KV25. The highest efficiency (94%) of ethanol production was achieved when the uncooked RWC slurry contained 23.03% starch. The optimal SSF conditions were determined as 1.125 units of the raw-starch-digesting enzyme per gram of RWC, a fermentation temperature of $30^{\circ}C$, slurry pH of 4.5, 36-h-old seeding culture, initial yeast cell number of $2{\times}10^7$ per ml of slurry, 17 mM of urea as the nitrogen additive, 0.25 mM of $Cu^{2+}$ as the metal ion additive, and a fermentation time of 90 h. Under these optimal conditions, the ethanol production resulting from the SSF of the uncooked RWC slurry was improved to 16.8% (v/v) from 15.1% (v/v) of pre-optimization.

• Journal of the East Asian Society of Dietary Life
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• v.21 no.4
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• pp.514-519
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• 2011

Takju was manufactured using 150 g Rosa rugosa Thunb. (Haedanghwa) and two different preparations of 3,000 g each of cooked and uncooked rice. Nuruk (150 g) and yeast (60 g) were inoculated into both mixtures for fermentation, and physiochemical changes were investigated during 14 days of fermentation. The final brix value, pH, and ethanol concentration of Haedanghwa (uncooked rice Takju) were $13.0^{\circ}$Bx, 4.3, and 11.8%, respectively, whereas those of Haedanghwa (cooked rice Takju) were $14.0^{\circ}$Bx, 4.6, and 14.4%, respectively. Lactic and acetic acid levels in Haedanghwa (uncooked rice Takju) were significantly higher than those in Haedanghwa (cooked rice Takju) (p<0.05). The level of ${\gamma}$-amino-n-butyric acid in Haedanghwa Takju (uncooked rice) was twice than that of Haedanghwa Takju (cooked rice). Our results demonstrate that the use of uncooked rice in the preparation of Takju may help improve the taste and function of the final product.

• Applied Biological Chemistry
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• v.27 no.3
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• pp.198-203
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• 1984

Ethanol fermentation of chemically gelatinized starch and uncooked raw starch was nested with various starchy materials. Starches were gelatinized by 5.4% NaOH and neutralized by sulfuric acid. The patterns of $CO_2$ evolving and the ethanol yield for the chemically gelatinized starch resemble those obtained with thermally gelatinized starch. The alcoholic fermentation of raw starch was carried out by the simultanous saccharification-fermentation using a commercial glucoamylase and yeast. Ethanol yield from uncooked rice starch fermentation was highly comparable to that from cooked one. $CO_2$ evolving rates of the uncooked starches of corn, barley, tapioca and sweet potato were lower than those of the cooked starches. However, the final ethanol yields were similar or slightly lower, depending on the types of starch.

• KSBB Journal
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• v.27 no.4
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• pp.251-256
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• 2012

In this study we investigated the effect of temperature on the two-stage fermentation of Makgeolli using uncooked germinated black rice. The fermentation processes were conducted at $15^{\circ}C$ for three weeks and $25^{\circ}C$ for 7 days. The pH of Makgeolli at $25^{\circ}C$ increased from pH3.0 to pH 4.2, which was consistent with that at $15^{\circ}C$. In contrast total acidity of Makgeolli at $15^{\circ}C$ was about half of that at $25^{\circ}C$ (0.36% and 0.59%, respectively). By the 7 days-fermentation at $25^{\circ}C$, 11% of alcohol was produced, whereas three weeks were required for the same alcohol production at $15^{\circ}C$. In the case of sugar contents, the amounts of total glucose-equivalent reducing sugars and glucose increased at the end of the fermentation at $25^{\circ}C$ up to 2.25 mg/mL and 3.4 mM, respectively, whereas those at $15^{\circ}C$ were maintained at very low levels (0.18 mg/mL and 0.1 mM, respectively). Such limited supplement of sugars at $15^{\circ}C$ seemed to affect metabolism of yeast, resulting in different composition of organic acid. At $25^{\circ}C$, citric acid that was 73.4 ppm at the initial fermentation was consumed completely, whereas 20 ppm of citiric acid was remained at $15^{\circ}C$. In addition, acetic acid and lactic acid in Makgealli at $15^{\circ}C$ were 53% and 14% of those at $25^{\circ}C$.

• Korean Journal of Food Science and Technology
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• v.44 no.2
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• pp.202-206
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• 2012

In order to prepare rice vinegar, $takju$ fermentation was performed, using two different compositions; cooked rice supplemented with $Rosa$ $rugosa$ Thunb. (CR-R) and uncooked rice supplemented with $Rosa$ $rugosa$ Thunb. (UR-R). After ethanol fermentation, ethanol contents of $takju$ were adjusted to 6.0%, and then acetic acid fermentation was carried out using $Acetobacter$ $aceti$ at $30^{\circ}C$ with 200 rpm for 9 days. Supplementations of 1% acetic acid to $takju$ prior to acetic acid fermentation were a critical step in achieving a successful fermentation; final organic acid contents increased in a dose dependent manner. A higher content of organic acids, 1.6-6.9%, was found in UR-R vinegar. The level of free amino acid and GABA in UR-R vinegar was higher than that of CR-R vinegar, with glutamic acid and arginine, as the major amino acids. This finding demonstrates that heating process of rice prior to ethanol fermentation affects the quality of vinegar significantly.

• 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 the Korean Society of Food Science and Nutrition
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• v.32 no.3
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• pp.375-380
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• 2003

The study was carried out to set up alcohol fermentation condition for uncooked brown rice. Response surface methodology (RSM) was applied to optimize and monitor of the alcohol fermentation condition with uncooked brown rice. The primary variables were conducted the reaction surface regression analysis for the particle size of brown rice (20 40 60 mesh) the enzyme content (0.1,0.3,0.5%) and the agitating rate (0,100,200 rpm). Their optimization was 35~42 mesh for the size of particle and 0.32~0.43% for enzyme content by SAS (Statistical Analysis System). The coefficient of determination ($R^2$) in ingredients was admitted at the significant level of 5~10% in all ingredients except for a reducing sugar. Predicted values at optimum alcohol fermentation condition agreed with experimental values. During the fermentation, pH was decreased from 6.25 to 4.34, and total acidity was increased from 0.15 to 0.2. The amino acidity was decreased from 1.88 to 0.92, reducing sugar and total sugar contents were decreased 213 mg% and 1,077 mg%, respectively. Alcohol content was increased to 10% after 48 hr fermentation.