• Food Science and Preservation
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• v.6 no.2
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• pp.233-238
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• 1999

This study was determined changes of components of sweet and astringent persimmon vinegars by two stages fermentation. Free sugars of persimmon juices before alcohol fermentation were mainly composed of glucose, fructose and sucrose. The content of glucose, fructose and sucrose of sweet persimmon juice was 6.60, 6.12 and 1.74%, respectively, and those of astringent persimmon was 5.63, 5.21, 0.62%, respectively. The contents of free sugar decreased continuously during fermentation. Major organic acids of persimmon juices were acetic, galacturonic, malic, citric and ascorbic acid. Alcohols of persimmon juices was detected methanol, ethanol, iso-propylalcohol, n-propylalcohol and iso-butylalcohol at the initial fermentation. The contents of alcohols increased continuously up to 4days of fermentation but their contents except ethanol decreased slightly at 5th day of fermentation. Contents of free amino acid were higher in sweet persimmon than those in astringent persimmon. Volatile components increased during acetic acid fermentation.

• The Microorganisms and Industry
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• v.19 no.4
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• pp.37-38
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• 1993

역사적으로 알콜은 인류에게 식품으로써 뿐만 아니라 근래에는 미래의 무공해 대체 에너지로써 많은 기대를 모으고 있다. 식품의 용도로써는 단연 주류를 꼽게 되는데 이 목적으로는 알콜의 발효수율을 올리는 것만이 아니라 소비자의 기호에 맞는 향과 맛등이 중요한 인자로 작용하게 되어 균주 조작에 한계가 있다고 보겠다. 반면 대체 에너지로써의 알콜은 가능한 수단 방법을 다 동원해서 값싸게, 수율높게만 개선하면 되기 때문에 최근 인구에 회자되고 있는 각종 생명공학기법이 광범위하게 사용될 수 있다고 본다. 목적에 따라서 원료는 물론 발효균주도 다양하게 사용되어 지는데 다음에서 용도별로 대표적인 예를 살펴보겠다.

• 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.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.

• Microbiology and Biotechnology Letters
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• v.14 no.2
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• pp.193-198
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• 1986

Improvement of productivity in ethanol fermentation was attempted using a hollow fiber bioreactor (HFR) where Saccharomyces cerevisiac var. ellipsoideus cells were recycled to achieve a high yeast concentration. Industrial wort was used as the fermentation media without supplying any additional nutrients. The performances in hollow fiber recycle reactor (HFR) were compared with those of batch and continuous cultures. In a continuous culture with 11$^{\circ}$P and 15$^{\circ}$P wort media final ethanol concentrations were 4.71% and 5.82% (v/v) and yields 86.2% and 78.6% respectively when the dilution rate (D) was 0.1 h$^{-1}$, in contrast, the ethanol concentration and productivity in HFR were 7.64%(v/v) and 6.1g/l/h at D=0.1h$^{-1}$ with 15$^{\circ}$P media. When the dilution rate was increased to 0.2 h$^{-1}$, the concentration and the Productivity were 7.62% (v/v) and 12.2g/l/h. At D=0.3h$^{-1}$ the sugar was completely consumed and the productivity was 18.1g/l/h. This correponds to 4 times that in continuous system and 16.3 times that in the batch system performed in comparable conditions.

• Applied Biological Chemistry
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• v.27 no.3
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• pp.139-145
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• 1984

For the ultimate manufacture of vinegar with watermelon juice, we examined the preliminarily alcoholic fermentation of watermelon juice using Saccharomyces cerevisiae, Saccharomyces cerevisiae var. ellipsoideus and Kluyveromyces fragilis. The juice contained 3.2% total reducing sugar by the Somogyi-Nelson method. Strains of yeast culture, pH, temperature and concentration of sugar in the juice were important factors affecting alcoholic fermentation. Saccharomyces cerevisiae var. ellipsoideus produced 5.3% alcohol from the juice fortified with 12% glucose under the conditions of pH 5.73 and $27^{\circ}C$ for 8 days. Generally, small quantities of various salts and N-sources affected little the alcoholic fermentation of the juice. The sterilization of the juice by autoclaving improved efficiency of fermentation than that by $SO_2$ sterilization. Determination of alcohol was carried out by the gas chromatographic method using Chromosorb W: Carbowax as packing material.

• Korean Journal of Food Science and Technology
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• v.34 no.1
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• pp.30-36
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• 2002

To use overproduction muskmelon effectively, muskmelon vinegar was prepared by two stage fermentations of alcohol and acetic acid. In the alcohol fermentation using muskmelon, alcohol content showed maximum value (7.47%) in $17.83^{\circ}Brix$ of initial sugar concentration and 82.65 h of fermentation time. Acetic acid content in alcohol fermentation revealed minimum value (0.46%) in $12.17^{\circ}Brix$ of initial sugar concentration and 60.56 h of fermentation time. The fermentation conditions for minimum residual sugar were $10.02^{\circ}Brix$ of initial sugar concentration and 105.61 h of fermentation time. The optimum conditions predicted for each corresponding physical properties of acetic acid fermentation were 200 rpm (agitation rate), 250 h (fermentation time) in acetic content and 200 rpm, 150 h in residual alcohol content.

• Food Science and Preservation
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• v.6 no.2
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• pp.228-232
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• 1999

Total acidities were incereased gradually during fermentation. Total acidities of vinegars which fermented from sweet and astringent persimmon were 5.95 and 5.81% at 8th day of acetic acid fermentation, respectively. Hunter's color values were not significant difference during alcohol fermentation and acetic acid fermentation. Browning incereased continuously during alcohol fermentation whereas browning and turbidity decreased continuously during acetic acid fermentation. The browning and turbidity of vinegar which fermented from sweet persimmon was higher than those of vinegar which fermented from astringent persimmon. The contents of total tannin were 2.40 and 6.44mg/ml at the initial fermentation of sweet and astringent persimmon respectively. But in contents decreased continuously during fermentation. Reducing and total sugar contents decreased continuously during fermentation. At 5th day of acetic acid fermentation, contents of reducing and total sugar were 5.0 and 8.5mg/ml in sweet persimmon and 2.8 and 2.9mg/ml in astringent persimmon respectively.

• KSBB Journal
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• v.4 no.2
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• pp.191-196
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• 1989

Functional relationship between the Fermentation characteristics of Functional relationship between the Fermentation characteristics of S. cerevisiae SIV-89 and the fermentation time was investigated. According to the increase in the initial sugar cone. from 50g/L to 80 g/L, maximum specific growth rate and maximum specific alcohol production rate were increased until 0.35 and 1.98. But the two values were decreased with increase of initial sugar cone. in the region of more that 80 g/L. Maximum alcohol yield and biomass yield were 0.45 and 0.15 respectively. However those vlaue were found to be reduced with the argument of initial sugar concentration. Sugar conversion was decreased with sugar concentration. When the sugar concentration was more than 190 g/L, the conversion was dropped below 70%. The increase of alcohol concentration in the fermentation broth induced the phenomenon of decline of metabolism. In case of more than 80 g/L of alcohol conc., biomass growth and alcohol production were completely stopped regardless of remaining sugar concentration.

• Korean Journal of Medicinal Crop Science
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• v.8 no.4
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• pp.351-361
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• 2000

The juice extract of Rehmannia glutinosa Liboschitz was used to improve the productivity of ethanol in alcohol fermentation process using a 5 L fermentor under batch and fed-batch cultivations. For batch cultivation, both cell density and ethanol production were increased as the extract of R. glutinosa was increased, showing 11.8 (g/L) of maximum cell density and 0.092 (% /hr) of maximum alcohol productivity in adding 30% (v/v) of the extract. However, in adding more than 40% of the extract both cell growth and ethanol production were dropped. The cell growth was severely inhibited in 50% addition. It was found that fed-batch cultivation in adding 30% of the extract of R. glutinosa was an effective process than batch cultivation, yielding up to 30% cell growth and ethanol production. This ethanol productivity was also 30-40% higher than that obtained from a conventional alcohol fermentation. It can tell that dried R. glutinosa Liboschitz is to be used for both enhancing the yield of alcohol fermentation and utilizing biologically active substances possibly transported from R. glutinosa Liboschitz into fermented broth.