• Korean Journal of Food Science and Technology
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• v.16 no.1
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• pp.90-94
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• 1984

We deduced a possible metabolic pathway of L-malate in a malo-alcoholic yeast, Schizosaccharomyces japonicus var. japonicus St-3. The malic enzyme (EC 1.1.1.40) prepared from the microorganism was about four times as active as that of malate dehydrogenase (EC 1.1.1.37). And Km values of malic enzyme and malate dehydrogenase for malate were found to be 3.125 mM and 4.761 mM, respectively, which referred to the fact that the affinity of malic enzyme for the substrate was greater than that of malate dehydrogenase. We also found that pyruvate was produced with disappearing malate in malo-alcoholic fermentation, and that the addition of $Mn^{2+}$ activated malic enzyme activity. Based on these results obtained we have deduced a main pathway of malate${\rightarrow}$pyruvate${\rightarrow}$acetaldehyde${\rightarrow}$ethanol for the utilization of L-malate by this malo-alcoholic yeast strain.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.6
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• pp.769-776
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• 2022

As an aquatic plant, the lotus leaf Nelumbo nucifera is rich in polyphenols, carotenoids, and flavonoids. We analyzed the chemical (pH, acidity, sugar, alcohol), microbiological (lactic acid bacteria, yeast), and antioxidant activity of Makgeolli supplemented with 5% and 10% lotus leaf (ll) during fermentation for 7 days. The pH of the non-additive group (control) was 3.10-6.03, that of the 5% added group was 3.17-5.77, and that of the 10% added group was 3.27-5.70, which decreased significantly (P<0.05) as the fermentation time elapsed. The acidity and sugar content were 1.89-2.12% and 9.10-12.90 Brix, respectively, which were significantly higher (P<0.05) as the amount of added ll increased. The alcohol content was 5.90-7.20% and was the highest on the seventh day of fermentation. The lactic acid bacteria was 6.07-7.17 log CFU/mL, which was higher in ll Makgeolli. Yeast increased until day 3 and then decreased to 3.27-5.86 log CFU/mL. DPPH (1,1-diphenyl-2-picrylhdrazyl) and ABTS [2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)] radical scavenging activities were higher in ll Makgeolli (DPPH 68.72-81.48%, ABTS 90.71-91.67%). In this study, the commercialization potential of ll Makgeolli was expanded by enhancing the quality and antioxidant function of Makgeolli added with ll.

• Journal of Life Science
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• v.18 no.7
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• pp.947-951
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• 2008

Zinc is an essential trace element participating in many physiological functions and notably an important function for sperm physiology. Zinc-enriched yeast strain, Saccharomyces cerevisiae, isolated from tropical fruit rambutan. This strain contained 306 ppm zinc concentration and other components contained by K 28,640 ppm, Mg 2,342 ppm, Na 1,048 ppm, Ca 366 ppm, Fe 236 ppm and Mn 4 ppm. The serum concentration of testosterone was decreased in ethanol treatment rats. As compared with ethanol treated control rats, the zinc-enriched yeast strain supplementation showed significantly increased the testosterone concentration in serum. In addition, zinc concentration in serum was decreased in alcohol treatment, but this reduction was significantly increased by zinc-enriched yeast strain supplementation in ethanol feeding rats. These results indicate that zinc-enriched yeast Saccharomyces cerevisiae strain could play an important role in the sperm physiology by the marked elevation of serum testosterone concentration.

• Food Science and Preservation
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• v.13 no.4
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• pp.490-494
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• 2006

Alcohol fermentation conditions were investigated using 'Cheondobansi' astringent persimmon (Diospyros kaki T.) for the study of persimmon wine and distilled liquor, The optimal yeast strain for 'Cheongdobansi' astringent persimmon alcohol fermentation was Saccharomyces kluyveri DJ97, which showed 10.8% of alcohol concentration, 96.25% of alcohol yield, and 935 ppm of methanol. The initial conditions of $22^{\circ}Brix$ and 120%(v/w) water addition resulted in the highest alcohol concentration of 10.7%. The alcohol concentration was higher in pectinase non-treated samples than in pectinase-teated samples. Lower concentrations of acetaldehyde and n-propanol were measured for the pectinase-treated sample than for the non-treatment samples. However, the methanol concentration of the pectinase-teated sample was higher than that of the pectinase non-treatment sample.

• 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.

• Korean Journal of Food Science and Technology
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• v.36 no.1
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• pp.50-57
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• 2004

Selection of yeast strains, optimum conditions for alcohol fermentation, sterilization methods, and additives for improving wine quality were investigated to manufacture watermelon wine. Eight yeast strains exhibited significant alcohol fermentation, among which KWS 06 was selected for watermelon wine fermentation, because watermelon wine made by this strain showed the best overall acceptability in sensory evaluation. Sucrose was determined as the best saccharide for alcohol fermentation among sucrose, corn syrup, glucose, fructose, and lactose. Optimum concentration of soluble solid and $(NH_{4})_{2}HPO_{4}$ of nitrogen source were $24^{\circ}Brix and 0.2%, respectively. Addition of raspberries and omija increased wine flavor and alcohol production, respectively, with optimum alcohol production, taste, and color achieved with addition of 20 g/L raspberries and 10 g/L omija. Best sensory quality was obtained by addition of 0.04 % watermelon flavorant to the juice.

• Korean Journal of Food Science and Technology
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• v.46 no.2
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• pp.143-147
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• 2014

In this study, we investigated the effect of various yeast nutrients on stuck and sluggish fermentation of blueberry wine. Sugar consumption rates during fermentation were observed after the addition of yeast extract, diammonium phosphate, yeast energizer, raisin, or banana to fermenting blueberry wine. After fermentation, the alcohol concentrations of wines containing yeast extract (14.1%) and banana (13.3%) were higher than those of wines containing diammonium phosphate (12.6%), yeast energizer (12.4%), and raisin (11.4%). Correspondingly, levels of soluble solids were lower in wines to which yeast extract ($3.9^{\circ}Bx$) and banana ($2.5^{\circ}Bx$) were added than in wines to which diammonium phosphate ($4.6^{\circ}Bx$), yeast energizer ($4.6^{\circ}Bx$), and raisin ($6.3^{\circ}Bx$) were added. Thus, we concluded that banana could be used as a nutritional supplement for yeast to solve stuck and sluggish blueberry wine fermentation.

• Korean Journal of Food Science and Technology
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• v.36 no.1
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• pp.92-96
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• 2004

Chitin and its derivatives (chitosan and glucosamine) were studied for their effects on ethanol production using YPD (yeast extract 10%, peptone 20%, glucose 20%, agar 20%) medium. All chitin derivatives, particularly chitin, increased ethanol production compared with control. In non-steamed alcohol fermentation of tapioca, addition of 0.9% chitin yielded higher ethanol production (13.6%) with lower acetaldehyde (21.91 ppm) and methanol (65.49 ppm) contents than those (12.7%, 35.05 ppm, 84.31 ppm, respectively) of control after fermentation for 120 hr at $30^{\circ}C$. Results indicate that chitin can be used to increase ethanol production in non-steamed alcohol fermentation of tapioca.

• Applied Biological Chemistry
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• v.15 no.1
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• pp.19-25
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• 1972

A kind of peptide which posseses an yeaststatic activity was isolated from Astragalus membranaceus Bunge and following characteristics was obtained. 1. The isoelectric pH of this peptide was 8.2 and histidine, an alkaline amino acid, was identified from this peptide. 2. This substance showes conspicuous heat stability and does not indicate any remarkable reduction of yeaststatic activity even for 5 hours treatment at $100^{\circ}C$. or for 30 minutes at $121^{\circ}C$. 3. The inhibitory activity of the yeast growth is not originated from the yeastcidal action but yeaststatic effect of this sample. 4. The sample shows strong stability ranging from pH 2 to 10. 5. The saccharide; glucose, sucrose, maltose, gives no effect on the yeaststatic activity of the sample even high concentration, 15 percent, and also no effect gives by magnesium, calcium and phosphate salts. 6. The available concentration of this sample on the inhibition of yeast growth was located at the ppm extent, for example, the concentration of fifty percent growth inhibition to Saccharomyces cerevisiae or S. carsbergensis was 4 ppm and 3 ppm to Candida pulcherrima, 13 ppm to S. coreanus, 18 ppm to S. sake and 38 ppm to C. tropicalis. 7. On the alcohol fermentation of S. coreanus, the peptide, an yeast growth inhibitor, gives no effect at all. 8. This substance is named as Astradix-P (Astragalus membranaceus, Radix, Peptide).

• KSBB Journal
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• v.27 no.1
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• pp.21-27
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• 2012

Five yeast strains were isolated from traditional Makgeollies, Makgeollies were made by isolated yeasts after cultivation, and then property changes of Makgeollies were analyzed according to yeasts, storage temperatures and storage periods. Average pHs were shown to be 3.22~3.88 and statistically changed according to yeasts used, storage temperatures and storage periods. Total acidities were statistically changed according to storage periods. Amino-type nitrogen contents were in the ranges of 0.009~0.245% and statistically changed according to storage temperatures especially at 18 and $25^{\circ}C$ for 15 days. Average alcohol concentrations were in the ranges of 7.5~18.5% and reduced until 10 days and increased for 15 days according to yeasts used and storage periods. Consequently, Makgeollies, made by isolated yeast strains originated from traditional Makgeollies, revealed that alcohol concentrations and amino-type nitrogen contents were changed but pHs and total acidities were not dramatically changed according to yeasts used. It suggests that development of various Makgeollies would be possible using isolated yeast strains in this study, and optimal storage condition of ready-made Makgeollies to maintain its original property turned out to be at $4^{\circ}C$ for 5 days. Especially, Makgeolli made by F strain showed the best quality on its property, therefore Makgeolli which maintains its property stably until 10 days when stored at $4^{\circ}C$ could be made using this strain.