• Journal of the East Asian Society of Dietary Life
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• v.8 no.1
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• pp.57-65
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• 1998

To utilize deteriorated sweet persimmon effectively, response surface methodology(RSM) was used to determine the optimal vinegar fermentation conditions and monitored by a divided two stage fermentation. The optimum conditions for maximum alcohol content were obtained when the first stage (alcohol fermentation) was carried out with an initial sugar concentration of 18.5$^{\circ}$Brix, agitation rate of 140.8 rpm, fermentation time of 127.6 hr. When sugar concentration was 14$^{\circ}$Brix maximum alcohol content(7.1%) was predicted at fermentation conditions of 160 rpm in agitation rate, 140hr in fermentation time. The optimum conditions for maximum acidity were obtaiend when second stage(vinegar fermentation)was carried out 249.5 rpm in agitation rate, 148.8 hr in fermentation time. Predicted values at the optimum conditions were similar to experimental values.

• Microbiology and Biotechnology Letters
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• v.22 no.5
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• pp.531-537
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• 1994

This study was undertaken with objective of optimizing the conditions of fermentation in an aqueous two-phase system which is composed of polyethylene glycol (PEG) 20000 and crude dextran (Dx). The data were obtained and analyzed using the Box-Wilson's experimental design protocol and the response surface methodology. To reach this end a multilinear polynomial regres- sion model was developed, which can be utilized for the purpose of optimizing the extractive fermentation. Optimum conditions for batch fermentation with aqueous two phase system were found to be at 4.2~5.4% PEG/3.2~4.2% Dx range. The composition of the center was 4.8% PEG/ 3.6% Dx. Optimum operating conditions for initial sugar concentration and fermentation time were approximately 160 g/l, and 21~22 hr, respectively. Fermentation in the aqueous two phase system composed of 5% PEG/4% Dx showed increase of 23% in ethanol concentration, of 9.5% in ethanol yield, and of 19% in ethanol productivity as compared to the case of fermentation of neat Jerusalem artichoke juice.

• Food Science and Preservation
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• v.30 no.6
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• pp.905-917
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• 2023

The optimal fermentation conditions for producing fermented black soybeans rich in sulfur-containing amino acids were investigated. Response surface methodology monitored fermentation conditions. A central composite design examined the effect of independent variables: enzyme concentration (X₁) and fermentation time (X₂) on yield and methionine content. Both factors significantly influenced these dependent variables. Enzyme concentration more profoundly affected amino nitrogen content than fermentation time. β-Glucan content and cystine level were primarily affected by fermentation time. We elicited each variable's regression formula and identified optimal fermentation conditions for functional compounds. The predicted optimum conditions were an enzyme concentration of 0.28-0.32% and a fermentation time of 58.0-62.0 min. Under these optimal conditions, each black soybean variety's sulfur amino acid content ranged from 818.62 to 922.62 mg/100 g, demonstrating significant variety differences.

• Food Science and Biotechnology
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• v.18 no.5
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• pp.1083-1090
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• 2009

Fermentation of wort was investigated with an ultimate goal to develop a fermented beverage rich in prebiotics and functional ingredients as well as desirable in flavors. Wort was fermented with Leuconostoc citreum HJ-P4 originated from kimchi and subjected to sensory descriptive analysis. L. citreum HJ-P4 produced various organic acids (e.g., lactic acid, acetic acid) as well as functional sugars (e.g., mannitol, panose) during wort fermentation. The concentration and ratio of lactic acid and acetic acid were significantly influenced by roasting conditions of malts used for wort preparation and aeration conditions during fermentation. The concentration of mannitol and panose varied depending on the sucrose content of wort and aeration conditions. Sensory characteristics of the fermented worts were clearly differentiated according to the roasting conditions of malts used for wort preparation and aeration conditions during fermentation. These results indicate that metabolite concentration of fermented wort and its sensory properties can be manipulated with roasting conditions of malts and fermentation conditions.

• Journal of Microbiology and Biotechnology
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• v.17 no.2
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• pp.297-304
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• 2007

The effect of yeast propagated at different aeration conditions on yeast physiology, fermentation ability, and beer quality was investigated using three strains of Saccharomyces cerevisiae. It was shown that yeast cells grown under continuous aeration conditions during propagation were almost two times higher as compared with discontinuous aeration conditions. The maximum of cell growth of all samples reached between 36 hand 48 h. The concentration of trehalose was increased under continuous aerated yeasts, whereas glycogen was decreased. It was also observed that the concentration of glycogen and trehalose in yeast cells had no direct effect on subsequent fermentation ability. The effect of yeast propagated under different aeration conditions on subsequent fermentation ability was different from yeast strains, in which the influence will be most pronounced at the first fermentation. Later, the yeasts might regain its original characteristics in the following fermentations. Generally, continuously propagated yeast had a positive effect on beer quality in subsequent fermentation. Hence, the concentration of aroma compounds obtained with yeast propagated under 6 1/h for 48 h aeration was lower than those grown under other aeration conditions in the bottom yeasts; in particular, the amounts of phenylethyl alcohol, ester, and fatty acids were decreased.

• Journal of Environmental Science International
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• v.21 no.10
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• pp.1255-1263
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• 2012

Batch cultivations were performed to evaluate the influences of the initial pH condition on mesophilic and thermophilic acidogenic fermentation with food waste recycling wastewater. In both conditions of mesophilic and thermophilic fermentation, TVFAs production rates were maximized at the initial pH 7 condition as 0.15 and 0.23 g TVFAs/L hr, respectively. And pH was also maintained stably between 6 and 7 during 72hr acidogenic cultivation at both conditions. However, predominant VFA components were different according to reaction temperature conditions. In mesophilic condition, propionic acid which has low conversion efficiency to methane was accumulated up to 1,348 mg/L while acetic and butyric acid were predominant in thermophilic condition. Therefore, thermophilic acidogenic fermentation was superior for the effective VFAs production than mesophilic condition. From the DGGE analysis, the band patterns were different according to the initial pH conditions but the correlations of the each band were increased in similar pH conditions. These results mean that microbial communities were certainly affected by the initial pH condition. Consequently, the adjustment of the initial pH to neutral region and thermophilic operation are needed to enhance acidogenic fermentation of food waste recycling wastewater.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.8
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• pp.986-996
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• 2017

In this study, we optimized fermentation conditions for burdock vinegar by response surface methodology. We confirmed the fermentation characteristics and major components of burdock vinegar. Alcohol fermentation of burdock extract added with 15% apple concentrates for vinegar production was performed. Consequently, 6.4% alcohol was produced after 5 days of fermentation. Central composite design was applied to investigate the effects of two independent variables, fermentation time (5~17 days; X1) and fermentation temperature ($26{\sim}34^{\circ}C$; X2), on fermentation of burdock vinegar. Fermentation conditions were optimized using characteristics of fermentation broth as a dependent variable. Acetic acid contents of dependent variables were 3.85~4.73% during acetic acid fermentation. The correlation coefficient ($R^2$) of the derived equation from the response surface regression for acetic acid contents was 0.9850 with significance level of 1%. Arctiin contents of all fermentation samples were 0.37~0.50 mg/100 mL, with an $R^2$ value of 0.8380 and significance level of 5%. We elicited a regression equation for each variable and superimposed the optimum area of fermentation conditions for characteristics and effective constituent contents of the fermentation broth. The predicted values for the optimum fermentation conditions for burdock vinegar were at $31^{\circ}C$ and 16 days.

• Food Engineering Progress
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• v.15 no.4
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• pp.355-361
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• 2011

The separation conditions for the enhancement of isoflavone contents in soybean by soaking and germination were developed, and the fermentation conditions of Chungkukjang were optimized by using response surface methodology analysis. The high-yield of isoflavone production was obtained when the conditions of soaking and gemination were at 25.6$^{\circ}C$, 7 hr and 29.1$^{\circ}C$, 42.4 hr, respectively. Total isoflavone contents in soybean (Daepung) by treatment were increased from 1,012 ppm to 1,912 ppm. Also, the optimum fermentation conditions of Chungkukjang were determined 39.96$^{\circ}C$, 1.32% (inoulum size) and 42.4 hr, respectively. Isoflavone contents in Chungkugjang under the optimum fermentation conditions were 1.3 times higher than the control (1,960 ppm).

• Korean Journal of Food Science and Technology
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• v.30 no.5
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• pp.1203-1208
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• 1998

To utilize astringent persimmon (Diospyros kaki, T.) effectively, response surface methodology (RSM) was applied to optimize and monitor the vinegar fermentation conditions by two stage fermentation. In the first stage, the fermentation conditions for maximum alcohol content was $20.51\;^{\circ}brix$ in sugar concentration of astringent persimmon, 139.52 rpm in agitation rate, and 94.88 hr in fermentation time. When sugar concentration of astringent persimmon was $14\;^{\circ}brix$, maximum alcohol content predicted by response surface methodology was 7.1% at agitation rate of 40 rpm and fermentation time of 120 hr. In the second stage, the fermentation conditions for maximum acidity was 224.40 rpm in agitation rate, 176.07 hr in fermentation time. Alcohol content and acidity predicted at the optimum conditions were similar to experimental values.

• The Korean Journal of Food And Nutrition
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• v.12 no.1
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• pp.1-6
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• 1999

The strain isolated for making chungkuk-jang was Bacillus subtilis which formed sport with 98% ratio. Logarithmical culture was inoculated(1,000 CF/g) to the steamed soybeans and at th optimum fer-mentation conditions(4$0^{\circ}C$, RH 90%) fermentation progressed very rapidly and synchronously. Fermen-tation time was 24 hours on the optimum fermentation conditions. During activated fermentation chun-gkuk-jang's aroma and flavor created. After finishing the fermentation the spore forming ratio was 95% and replenishment was not occured easily during aging at the below 5$^{\circ}C$.