• Microbiology and Biotechnology Letters
• /
• v.25 no.3
• /
• pp.266-270
• /
• 1997

From persimmon fruits, about 40 yeast strains were isolated and tested for their ability of alcohol fermentation were tested. Among them, two strains, RCY14 and RCY15, showing the highest alcohol fermentibility were selected for further investigations. They were identified as Saccharomyces cerevisiae and Saccharomyces kluyveri based on their morphological, cultural and physiological properties. Their optimum condition for the alcohol fermentation in YPD-15% glucose was pH 6.0, 30$circ$C and 120 rpm of shaking speed. The alcohol yields of S. cerevisiae RCY14 and S. kluyveri RCY15 in a persimmon juice were 94.54 and 96.81%, respectively. Although the alcohol yields of both strains were not very high in YPD-15% glucose, they were much higher in a persimmon juice as compared to those of S. cerevisiae Balyon-1, S. cerevisiae 701 and S. cerevisiaein W3 which are being used in the industrial alcohol fermentation.

• Preventive Nutrition and Food Science
• /
• v.11 no.2
• /
• pp.166-170
• /
• 2006

This study was carried out to investigate the fermentation characteristics and optimum conditions for alcohol fermentation of the Korean native mulberry. The yeast strains of S. kluyveri DJ97, La parisienne (Saccharomyces cerevisiae, Netherlands) and Enoferm (Saccharomyces cerevisiae, Denmark) produced higher alcohol concentrations than other strains, and further study was therefore performed with these three species. The optimum additional water content for maximizing alcohol concentration was 250% (v/w). The alcohol concentrations were rapidly increased in the first 4 days under the optimum conditions and reached 13.8% for S. kluyveri DJ97, 14.0% for La parisienne and 14.0% for Enoferm, respectively. Residual sugar concentration was decreased steadily from the beginning of fermentation until 5 days, after which it maintained a constant level. The pH was decreased steadily in the log phase during further maturation. However, the pH underwent a slight decrease after 4 days and then was stabilized during further maturation. Methanol concentrations for the three species used were analyzed after 60 days maturation and were lower than the levels regulated by the food standard. Fusel oils such as n-propanol, iso-butanol, and iso-amyl-alcohol were produced as by-products with the highest production from Enoferm and the lowest from S. kluyveri DJ97.

• The Korean Journal of Mycology
• /
• v.20 no.3
• /
• pp.269-272
• /
• 1992

208 yeast strains were isolated from air at El-Minia city, Egypt. Using 22 morphologi cal and physiological merkmals, these strains were identified and assignned to eight species belonging to seven genera. Rhodotorula mucilaginosa and Cryptococcus albidus were the most dominant species followed by Debaryomyces hansenii. These yeast species occurred regularly, whereas other species appeared sporadically. Rh. rubra, Saccharomyces kluyveri and Rh. aurantiaca were also isolated from the sampled air. The results of this study showed that time, hight and area of air sampling affect composition and total counts of yeast microflora in the air.

• Food Science and Biotechnology
• /
• v.16 no.4
• /
• pp.526-530
• /
• 2007

The objective of this study was to establish the optimum alcohol fermenting conditions for the processing of kiwi wine and vinegar products. Six yeast strains were examined for their alcohol production from kiwi at $30^{\circ}C$ for 72 hr with continuous shaking at 100 rpm. Under these conditions, Saccharomyces kluyveri DJ97 produced the highest alcohol content of 10.2%. As the fermentation time extended to 96 hr, the alcohol content reached a maximum of 12.75%. The optimum alcohol fermenting conditions for kiwi fruit were accomplished when kiwi was added to an equal amount of water, inoculated with S. kluyveri DJ97 and fermented at $30^{\circ}C$ for 96 hr with continuous shaking. The content of soluble solids decreased as the alcohol concentration increased, whereas little change was observed in the pH and titratable acidity during the low temperature aging process. Other alcoholic compounds, such as methanol, isopropanol, n-propanol, isobutanol, and isoamylalcohol, tended to increase as fermentation progressed.

• Food Science and Preservation
• /
• v.23 no.7
• /
• pp.1042-1049
• /
• 2016

This study was conducted to investigate and compare the characteristics of acetic acid fermentation in detoxified Rhus verniciflua vinegar (DRV) produced by different yeast strains. The DRVs were prepared by static acetic acid fermentation using six different yeast strains (Saccharomyces cerevisiae Fermivin, Pichia kudriavzerii N77-4, Hanseniaspora pountiae HP1-2, Candida tropicalis Y447, Wickerhamomyces anomalus N43-8, and Pichia kluyveri Frootzen). Alcohol content of the S. cerevisiae Fermivin fermented DRV was highest 16.07%. Among the yeast strain DRVs, there were significant differences in alcohol content, but all alcohol levels were 11%. Moreover, there were differences in pH and titratable acidity of the DRVs. The organic acid content of the DRVs ranged from 35.88 to 55.49 mg/mL and there were significant differences among the yeast strain DRVs. Essential free amino acids, particularly glutamic acid, alanine, leucine and valine, were detected in each of the 6 DRVs. Electronic nose analysis revealed that three different volatile chemical patterns were present in the 6 DRVs. The results indicate that yeast strains with different characteristics can produce vinegars with different characteristics.

• Food Science and Preservation
• /
• v.17 no.5
• /
• pp.733-740
• /
• 2010

Brown rice vinegars were prepared by agitated or static acetic acid fermentation using different yeast strains (Saccharomyces kluyveri DJ97, Saccharomyces cerevisiae JK99, Saccharomyces cerevisiae GRJ, or Saccharomyces cerevisiae H9). Organic acid contents and levels of volatile compounds were compared in vinegars prepared by different methods. The chosen yeast strain did not significantly affect the organic acid content of vinegar. In vinegars prepared by agitated acetic acid fermentation, organic acid contents were, in the order of descending abundance, acetic acid, citric acid, lactic acid, oxalic acid, and tartaric acid. In vinegars prepared by static acetic acid fermentation, no citric acid was detected, and lactic acid content was higher than that in agitated acetic acid fermented vinegar. The volatile compounds of both vinegars, analyzed by GC-MS, did not significantly differ when various yeast strains were used. Eighteen volatile compounds were detected in vinegar prepared by agitated acetic acid fermentation and 11 in vinegar prepared by static fermentation. Volatile compounds that can affect vinegar quality, including ethyl acetate and phenethyl acetate, were present at high concentrations in static acetic acid fermented vinegar. Electronic nose analysis showed that volatile chemical patterns differed between the two types of vinegar, but there were no significant differences in sensory scores between vinegars prepared using various yeast strains or by either of the two methods of fermentation.

• Microbiology and Biotechnology Letters
• /
• v.25 no.5
• /
• pp.435-441
• /
• 1997

Forty seven strains of yeast were isolated from traditional Meju and were identified as Saccharomyces spp. (7 strains), Zygosaccharomyces spp. (7 strains), Kluyveromyces spp. and Hansenula spp. (each 5 strains), Rhodotorular spp. (8 strains), Candida spp. (12 strains), Pichia spp. and Debaryomyces spp. from results of their microbiological characteristics. The optimal medium for growth of all the yeasts was YM media and the optimal initial pH of the medium was 6.0. The optimum temperature for growth was 30$circ$ and among them, Sacch. exiguus OE-5, Sacch. cerevisiae OE-16, Sacch. kluyveri C-1 strains were thermotolerant yeasts which could grow at 40$circ$C.

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

• Korean Journal of Food Science and Technology
• /
• v.17 no.2
• /
• pp.89-94
• /
• 1985

Seventy nine swollen commercially canned grapes and peaches were collected from wholesale and retail outlets in Seoul area for the investigation of the causes of their swell. Hydrogen generation and microbial spoilage were the only two common causes of can swelling. Nevertheless, the spoilage profile of the two products was different. Seventeen out of twenty one canned peaches were spoiled by microorganisms, while the rest of five were swollen due to hydrogen generation. In contrast, fifty one out of fifty eight canned grapes were swollen due to hydrogen generation, while the rest of seven were spoiled by microorganisms. Seventeen yeast and five bacterial strains were isolated and only the yeasts were identified to their genera and species. Saccharomyces cerevisiae was the most frequently isolated spoilage yeast, closely followed by Torulopsis stellata. Candida parapsilosis, Pichia kluyveri, Pichia membranaefaciens, Torulopsis globosa and Torulopsis lactis-condensi were also isolated but with lower frequencies.

• Korean journal of food and cookery science
• /
• v.4 no.1
• /
• pp.41-46
• /
• 1988

Omija tea with a pH range of 2.8~3.0 was stored at $25^{\circ}C$ to study its spoilage due to microbial growth. Titratable acidity was increasing during the storage period in the tea stored with the Omija fruits but not in removed of the fruits after extraction. Microbial cells began to show up earlier in the tea without the fruits than that with the fruits. Four strains of yeasts and a strain of mold were isolated from spoiled Omija tea. Morphological, cultural and physiological characteristics of yeasts were investigated and the yeasts were identified as Rhodotorula rubra, Saccharomyces kluyveri, Cryptococcus hungaricus and Candida humicola. Morphological characteristics of the isolated mold was observed and the mold was identified as Mucor circinelloides f. janssenii.