• KSBB Journal
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• v.4 no.2
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• pp.167-171
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• 1989

The alcohol fermentation using glucose and lactose was carried out to study the effect of fermentation temperature on the ethanol tolerance of Saccharomyces cerevisiae STV89 and Kluyveromyces fragilis CBS397. The maximum specific growth rate and ethanol production rate were increased up to 35$^{\circ}C$ with the fermentation temperature, although maximum ethanol and cell concentration were decreased by increasing the fermentation temperature. The cell viability was also improved by lowering the fermentation temperature. Under the experimental conditions, the best ethanol tolerance of yeast strains was obtain at $25^{\circ}C$. The ethanol tolerance of S. cerevisiae is better than that of K. fragilis at the same fermentation condition. With respect to the carbon source, glucose is found to be more favorable for ethanol tolerance of K. fragilis than lactos.

• Food Science and Biotechnology
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• v.16 no.5
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• pp.812-816
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• 2007

To overcome the problem of ginseng's earthy smell in the manufacture of ginseng wine, we used dried ginseng powder that was extrusion-cooked at $125-168^{\circ}C$ in the wine making process. By using a ginseng powder that was extrusion-cooked at higher temperatures, fermentation by Maillard reaction products (MRPs) was delayed, and the acidic pH that results from extrusion cooking was improved. At $15^{\circ}C$ with glucose instead of sucrose, an addition of 0.5%(w/v) diammonium phosphate (DAP) to the $125^{\circ}C$ extrusion-cooked ginseng powder reduced the primary fermentation time to 11 days versus 33 days without DAP. In the absence of DAP, by increasing the fermentation temperature from 15 to $30^{\circ}C$, increasing the starter yeast inoculate from 0.02 to 1 %, and by increasing the amount of ginseng extrudate from 1 to 2%, fermentation time was effectively reduced more than 10-fold. The results of this study may provide information for the alcohol fermentation of materials containing MRPs as well as for poor nitrogen sources.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.5
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• pp.752-757
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• 1995

The effect of fermentation temperature on the changes of pH, acidity, salt content, color and vitamin C of mustard leaf kimchi during various storage days was investigated. The conditions of fermentation temperature were set at $4^{\circ}C$ (sample A) and $20^{\circ}C$ (sample B), and $4^{\circ}C$ after keeping at $20^{\circ}C$ for 12 hours(sample C) and $20^{\circ}C$ for 36 hours(sample D). As the fermentation proceeded, pH of sample stored at low temperature(sample A) was drop ped gradually from initial pH of 5.24 but there was great pH drop in the sample stored at high temperature(sample B, D). The salt content of the sample B at high temperature increased remarkably, and then the values showed D > A > C. The Humter values of L and a increased at the optimum ripening period, the higher the initial fermentation temperature(B) and the later the initial fermentation time at $20^{\circ}C$ those values, then decreased. The Hunter value of b constantly increased until day of 108. As fermentation time passed, the content of total vitamin C decreased to the range of 9.0mg% to 14.0mg% up to 24 days of fermentation, and at the optimum ripening period, it increased to the range of 14.0mg% to 22.0mg%, and at the fermentation period(until day 108), it decreased gradually.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.2
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• pp.214-219
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• 2007

A $3{\times}3$ factorial design experiment was conducted to investigate the effect of temperature and duration of storage on the fermentation quality of potato pulp ensiled with two fungal inoculants under laboratory conditions. The inoculants, Rhizopus oryzae (R) and Amylomyces rouxii (A) were each added to potato pulp material to contain at least $1{\times}10^6$ CFU/g fresh matter, and silages without additives served as controls. The silages were stored under three temperature regimes; 4, 12 and $25^{\circ}C$. Three silos per treatment from every temperature regime were opened on days 7, 24 and 40 days after ensiling to investigate treatment effects on fermentation quality, starch and sugar concentrations. Increase in temperature and duration of storage had a positive significant effect (p<0.01) on the fermentation quality of potato pulp silage (PPS). The inoculants had little effect (p>0.05) on the fermentation quality of the silages. Sugar concentration in the silages decreased with increase in temperature (p<0.01) but increased (p<0.05) with progression of duration of storage. The fungal inoculants had no effect on starch degradation in PPS. The results suggest that storage temperature and duration of storage are more important in determining the rate of fermentation than addition of the fungal inoculants in PPS.

• The Korean Journal of Food And Nutrition
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• v.32 no.4
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• pp.371-378
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• 2019

This paper investigated the effects of the percentages of yeast and fermentation time as well as the top and bottom temperature of oven on the baking properties of rice bread. The specific volume of the dough decreased as the amount of added yeast and fermentation time increased. When 1.5% yeast was added at 60 min of fermentation time, the shape of the rice bread showed the largest volume, high appearance and a round shape. The top and bottom temperature of the oven on the baking characteristics of rice bread were affected by the baking time. When the top and bottom temperature of the oven at 200 and $140^{\circ}C$, and 200 and $170^{\circ}C$, the baking time was 20 min. When the top and bottom temperature of oven at 140 and $170^{\circ}C$, the baking time was 40 min. When the top and bottom temperature of the oven were 170 and $170^{\circ}C$, the shape of the rice bread indicated the largest volume, high appearance and a round shape. The results of this study revealed that the replacement of rice flour with 1.5% yeast, 60 min of fermentation time, and the top and bottom temperature of oven at $170-170^{\circ}C$ are effective for rice bread.

• Microbiology and Biotechnology Letters
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• v.14 no.3
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• pp.233-237
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• 1986

Possibility of large scale ethanol fermentation from sweet potato were compared with low temperature and high temperature rooking. Productivity of sweet potato mash cooked at 9$0^{\circ}C$ for 120 minutes was higher than that mash cooked at 124$^{\circ}C$ for 60 minutes and also fermentation yield ai low temperature cooking was better than high temperature cooking. Low temperature cooking was successfully carried out on a large scale. In conclusion, low temperature cooking on large scale should be reduce energy consumption by approximate 30% compared with high temperature cooking.

• Journal of Microbiology and Biotechnology
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• v.4 no.3
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• pp.222-229
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• 1994

In order to develop a method of economical production and to reduce energy-consumption in fuel alcohol production, we investigated the fermentation characters of two newly selected thermotolerant yeasts. The RA-74-2 showed stable and superior fermentability between 30 and $40^{\circ}C$ in 20% glucose media in comparison to the industrial strains. The optimum concentration of glucose for economical fermentation at $40^{\circ}C$ was 15-18%, and organic nitrogen was necessary for a satisfactory fermentation. The optimum pH was 4.0 and aeration was adversed for high temperature fermentation. Agitation was an important factor at $40^{\circ}C$ and the addition of magnesium ion 0.2% was required in this experiment. When the inoculum was increased, ethanol productivity as well as the speed of fermentation increased. On the other hand RA-912, which can grow at $48^{\circ}C$, showed similar fermentability between 30-$45^{\circ}C$ in 20% glucose media As the concentration of substrate decreased, fermentation ratio increased at $45^{\circ}C$ (45%, 65%, 95% fermentation ratio in 20%, 15%, 10% glucose media, respectively). Also, requirement of organic nitrogen and magnesium ion in RA-912 was similar in RA-74-2. The optimum pH for fermentation was 5.0, and the effects of agitation were enhanced at $37^{\circ}C$ than at $45^{\circ}C$. As the inoculum was increased, fermentation speed became more enhanced but the ethanol productivity was less affected. RA-912 showed fermentability with various substrates. Among the substrates used, inulin was the most promising substrate for the high-temperature fermentation. When 14.5% inulin was used as the substrate, 93% and 55% fermentation ratios were shown at $37^{\circ}C$ and $45^{\circ}C$, respectively.

• Korean journal of food and cookery science
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• v.23 no.2 s.98
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• pp.173-179
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• 2007

The effects of fermentation agent and fermentation temperature on the quality of Bori-sangoedduk We examined the effects of fermentation agent and fermentation temperature on the quality characteristics of Bori-sangoedduk a traditional dduk(rice cake) from Jeju, Korea. Bori-sangoedduk was prepared by mixing wheat flour, barely flour, and Borisul or Takju as the fermentation agent the mixture was then fermented at 30, 35, and $40^{\circ}$C. for 3 hr, and steamed. The L- value of the Takju group was higher than that of the Borisul group, and the samples fermented at $30^{\circ}$C in each group had higher than L-values than those fermented at $35^{\circ}$C and $40^{\circ}$C . The a- and b-values did not differ significantly by the fermentation agents and fermentation temperatures. The loaf volume of the Borisul group was higher than that of the Takju group however, there were no significant differences according to fermentation temperature. The values of hardness, springiness, and cohesiveness were lower in the Borisul group than in the Takju group due to a greater number of pores and surface cracks. Hardness, springiness, and cohesiveness values were highest at fermentation temperatures of 30, 35, and $40^{\circ}$C , respectively, in both groups, compared to samples at other temperatures. In the acceptance test, the Takju group was preferred over the Borisul group for appearance, texture, taste, flavor, and overall preference. There were also statistically significant preferences in taste, flavor, and overall preference for samples fermented at $40^{\circ}$C , in both groups, compared to those fermented at $30^{\circ}$C and $35^{\circ}$C. In the descriptive test, there were no differences in color according to fermentation agent and fermentation temperature, however, the Takju group was shinier than the Borisul group. In addition, the Takju group was harder and springier than the Borisul group, and had less sour taste and flavor than the Borisul group. Finally, in terms of overall preference, we found that Bori-sangoedduk made with Takju and fermented at $40^{\circ}$C for 3 hr was the best formula, due particularly to its taste and flavor.

• Applied Biological Chemistry
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• v.39 no.5
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• pp.398-402
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• 1996

This study was carried out to compare the fermentation rates of Dongchimi as affected by fermentation temperature and salt concentration of brining solution. The Dongchimi was prepared by fermentation of the radish in salt solutions of 2.0, 3.2 and 5.1% NaCl respectively with addition of garlic, green onion, ginger at $4^{\circ}C,\;10^{\circ}C,\;20^{\circ}C$. The fermentation was classified into 3 steps of initial, intermediate and final stages according to pH changes and the rates of fermentation and color change were calculated from intermediate stage. The time reached equilibrium in hardness of radish and salt concentration and their equilibrated values were also compared. Fermentation rate became more rapid as fermentation temperature and salt concentration increased. The rates of Hunter color change of Dongchimi liquid were increased as the temperature increased. The 'L' values decreased slowly, and 'a' and 'b' values increased rapidly to maximum at the intermediate stage. The time required to reach equilibrium was reduced for both salt concentration and hardness of radish as the fermentation temperature increased. The equilibrated values of salt concentration were increased while those of hardness of radish were decreased as the temperature and salt concentration increased. The data obtained can be used for prediction of some of the major characteristics of Dongchimi during fermentation.

• Korean Journal of Food Science and Technology
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• v.16 no.4
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• pp.443-450
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• 1984

Chemical and microbial changes during Kimchi (a group of Korean seasoned pickles) fermentation were carried out at various temperatures and salt concentrations. The time reaching optimum ripening of Kimchi varied depending upon fermentation temperature and salt concentration. At high temperature and low salt content Kimchi fermentation was faster than at low temperature and high salt content. The ratio of volatile to non-volatile acids reached its maximum at the optimum ripening time of Kimchi and decreased thereafter. Leu. mesenteroids, Lac. brevis, Lac. plantarum, Ped. cerevisiae, Str. faecalis and low acid producing Lactobacilli were isolated from Kimchi samples. However, the main microorganism responsible for Kimchi fermentation was Leu. mesenteroides and Lac. plantarum was the main acidifying organism. Total viable count increased rapidly in the beginning of fermentation and reached its maximum number at optimum ripening time and then decreased slowly as the acidity of Kimchi increased. While the total aerobic bacteria and fungi decreased during Kimchi fermentation, the yeast increased significantly at lower temperature.