• Journal of Environmental Science International
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• v.15 no.10
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• pp.975-982
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• 2006

This study has been conducted to optimum operating conditions for effective acid fermentation according to OLR(organic loading rate) in the mesophilic and thermophilic acid fermentation process. The results are summarized as follows. In order to obtain reasonable acid fermentation efficiency in performing acid fermentation of food wastes in thermophilic condition, organic loading rate was required below 20 gVS/L.d. As $SCOD_{Cr}/TKN,\;SCOD_{Cr}/T-P$ of thermophilic acid fermented food wastes In organic loading rate 20 gVS/L.d were 18.9, 73.4 respectively, it was possible to utilize as external carbon source for denitrification in sewage treatment plant after solid-liquid separation as well as co-digestion of fermented food wastes and sewage sludge.

• Preventive Nutrition and Food Science
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• v.17 no.1
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• pp.36-45
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• 2012

To produce novel cheese-like fermented soybean, the solid-state fermentation of roasted soybean flour (RSF) was performed using 1.0% inoculum Bacillus subtilis HA and Lactobacillus plantarum, with the initial 60% substrate moisture for 10 hr at $42^{\circ}$, resulting in pH 6.5, 0.82% acidity, 3.5% mucilage, 14.3 unit/g protease activity, 7.6 unit/g fibrinolytic activity, 216 mg% tyrosine content and $1.7{\times}10^{10}$ CFU/g of viable cell counts. After the second lactic acid fermentation with 10~30% skim milk powder, the fermented RSF resulted in an increase in acidity with 1.64~1.99%, tyrosine content with 246~308 mg% and protease activity in the range of 5.2~17.5 unit/g and 0.966 water activity. Viable cell counts as probiotics indicated $1.6{\times}10^8$ CFU/g of B. subtilis and $7.3{\times}10^{10}$ CFU/g of L. plantarum. The firmness of the first fermented RSF with 2,491 $g{\cdot}{\o}mm^{-1}$ greatly decreased to 1,533 $g{\cdot}{\o}mm^{-1}$ in the second fermented RSF, although firmness was slightly increased by adding a higher content of skim milk. The consistency of the second fermented RSF also decreased greatly from 55,640 to 3,264~ 3,998 in the presence of 10~30% skim milk. The effective hydrolysis of soy protein and skim milk protein in the fermented RSF was confirmed. Thus, the second fermented RSF with a sour taste and flavor showed similar textural properties to commercial soft cheese.

• Korean journal of food and cookery science
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• v.20 no.6 s.84
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• pp.598-606
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• 2004

The application of Dongchimi liquid to Naengmyon broth to improve its eating quality was scientifically explored by reviewing the quality of the product properties. Primarily, the optimum fermentation conditions for Dongchimi from which the liquid portion was extracted were pursued and the optimum mixing ratio sought on the basis of the product physicochemical properties. The liquid portions, periodically extracted from Dongchimi at intervals of two or five days, during fermentation at $10^{\circ}C$, were added to Naengmyon broth. The treatments were prepared at three levels namely, basic broth only ('A') and with ratios of Dongchimi liquid to basic broth of 3:7 (v/v, 'B') and 5:5 (vfv, 'C'). As a typical phenomenon of kimchi fermentation, a gradual decrease in the pH with increasing total acidity was observed as the fermentation of the Dongchimi progressed. At $10^{\circ}C$, the optimum ripening was obtained from day 8, and continued until day 15, when the pH was maintained at about 3.8 to 4.0. The total vitamin C and reducing sugar contents increased until the 13th-day of fermentation, but then decreased thereafter. The turbidity and solid content of the Dongchimi liquid increased with progression of the fermentation. With respect to the color values, the lightness (L) decreased, with increases in the redness (a), yellowness (b) and total color difference $({\Delta}E)$ during fermentation. Most of these observed phenomena for the Naengmyon broth substituted with $30\%$ (Treatment 'A') and $50\%$ (Treatment 'B') Dongchimi liquid, with different storage periods, confirmed the previous fermentation patterns of Dongchimi. A decrease in the pH with increasing total acidity, as well as gradual increases in the total vitamin C and reducing sugars (glucose and fructose) up to the 13th-day of fermentation were accompanied by subsequent declining patterns. The turbidity and solid content of the mixed broth also increased with increasing Dongchimi liquid fermentation period. With respect to the color of the mixed broth, the lightness was decreased, while the redness, yellowness and total color difference increased with increasing Dongchimi liquid fermentation period. It was also proven that the addition of slightly over-ripened Dongchimi liquid to the Naengmyon broth was more preferable.

• Korean Chemical Engineering Research
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• v.52 no.3
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• pp.402-406
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• 2014

The present study was carried out to evaluate the potential of lignocellulosic byproducts for the production of citric acid through solid-state fermentation by Aspergillus niger NRRL 567. A sequential optimization based on one-factor-at-a-time method was applied to optimize fermentation conditions and media constituents. The results obtained from the optimization indicated that $30^{\circ}C$, 70% moisture content, 0.5~1.0 mm particle size, pH 5.5 and 4% methanol were found to be the optimum condition at 72 hr fermentation. The application the optimization resulted in an improvement of maximum citric acid production from 74.5 to 206.0 g/kg dry material (DM) from wheat straw. The optimal condition was used to produce citric acid from A. niger grown on different lignocellulosic byproducts, including wheat straw, corn stover and peat moss. A. niger produced the highest citric acid levels of 231.8, 213.8 and 240.2 g/kg DM at 120 hr fermentation, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.17 no.3
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• pp.255-261
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• 1988

For the purpose of fermentation control and edible period extension of lower salted Kimchi, the contents and compositions of pectic substances in Kimchi, by adding 2 percent salt and 0.4 percent sodium malate buffer(SMB), fermented at $20^{\circ}C$ were investigated. Edible period of SMB added chinese cabbage Kimchi was extended 40 hrs compared to that of control (added 2.5% salt) with good flavor, texture and freshness. The contents of alcohol insoluble solid(AIS) and protopectin(PP) of control were more decrensed during fermentation than those of SMB added Kimchi. But, the contents of pectic adid(PA) and water soluble pectin(WSP) of control were more increased during fermentation than those of SMB added Kimchi. Hexose and pentose from hemicellulose in control, PP and PA respectively, were more decreased during fermentation than those in SMB added Kimchi. Lower polarity and higher molecular weight PP was eluted and higher polarity and lower molecular weight PP was decreased considerably in control compared to those in SMB added Kimchi during fermentation.

• Korean journal of food and cookery science
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• v.17 no.6
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• pp.555-564
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• 2001

The optional ingredient jasoja(Perillae semen) was adopted to improve Dongchimi in qualify during fermentation The final weight percentage of jasoja in Dongchimi was adjusted to 0, 0.25, 0.5, 0.75, or 1.0% Per radish. Physicochemical characteristics were determined during fermentation for 45 days at 10$^{\circ}C$. As the fermentation of Dongchimi proceeded, the pH decreased with the increase of total acidity; however, the decreasing rate was slowed down by increasing the level of jasoja. The delayed pH drop of Dongchimi was limited only for the initial period of fermentation and the ultimate pH became almost comparable even for the 1% treatment. The total vitamin C content increased initially to a certain level depending on the level of jasoja, and then decreased later. Dongchimi with 0.5% jasoja contained the highest level of total vitamin C and reducing sugars. In case of 1% treatment, the typical pattern of an initial high content followed by a gradual decrease in reducing sugar was destroyed by a rapid fermentation at the later stage. Turbidity level, along with total solid contents of the liquid part of Dongchimi increased in all treatments as the fermentation proceeded although the extent was rather suppressed by jasoja. As a result of fermentation, the colorimetric lightness values decreased, with the intial increase followed by the decrease at a certain point in redness and yellowness and the increase in color difference values (ΔE). Overall, fermentation with 0.5% jasoja for 11 to 30 days appeared to improve the quality of Dongchimi.

• Korean Chemical Engineering Research
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• v.50 no.5
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• pp.874-878
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• 2012

In the submerged fermentation of fungi, it was known pH had significant effect on the citric acid production. Various growth conditions were applied with different buffer on citric acid production by Aspergillus niger NRRL 567 grown on peat moss to find the optimum pH and most effective buffer solution. The initial pHs of different buffer solutions significantly influenced on the citric acid production and A. niger NRRL 567 produced citric acid more efficiently at high pHs. A phosphate buffer and a carbonate buffer with pH 8.6 and pH 10.0 were identified as suitable buffer solutions for citric acid production. The maximal citric acid production of 564.3 g/kg solid substrate was achieved employing carbonate buffer at pH 10.0.

• Microbiology and Biotechnology Letters
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• v.30 no.3
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• pp.253-257
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• 2002

The time-dependent changes of red pigments production in solid-state plant scale fermentor using barley cultured with Monascus sp., instead of rice which was traditionally used, were investigated in this study. A steady increase in the yield of red pigments in barley occurred between the 3rd and 6th days. The optimized conditions (inoculation volume = 6∼8%, initial pH = 6, air supply = 0.6∼0.8 m) promoted the production of red pigments. Short-time steaming of barley (< 20 min) decreased fungal growth and pigments production due to the insufficient gelatiniza-tion. The optical density of the red pigments under the optimized conditions was 120 at 500 ]nm per gram of barley. In addition, the metabolites from the fermented barley with Monucus sp. showed antibacterial effects against Escherichia coli and Salmonella typhimurium. Barley was shown to be one of the best grain sources for solid-state fermentation with Monascu sp., fur obtaining natural pigments and also functional food materials.

• Korean Journal of Food Science and Technology
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• v.31 no.4
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• pp.1044-1049
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• 1999

Fermentation characteristics for the production of honey wine (mead and melomel) was investigated. Among the yeast strains tested, Saccharomyces bayanus showed higher alcohol production and better fermentability than the other strains at low temperature. Optimum pH and temperature for the production of honey wine by Saccharomyces bayanus were pH 4.0 and $20^{\circ}C$, respectively, and optimum soluble solid content of diluted honey solution for the fermentation was between 24 and $27^{\circ}Brix$. Total acidity and pH of honey wine (mead) did not change considerably during the whole period of fermentation, but those of Tangerine and Japanese apricot honey wine (melomel) changed during the fermentation. As the fermentation progressed, reducing sugar decreased continuously until the late period of fermentation, while alcohol content increased continuously during the same period. After fermentation of 21 days, honey wine consisted of about $8.5{\sim}9.1^{\circ}Brix$ of soluble solid, $1.90{\sim}2.32%$ of reducing sugar with the conversion rate of $90{\sim}92%$. After 21 days of fermentation, alcohol contents of mead fermented with polyflower and acasia flower were 13.3 and 13.7%, respectively. Final alcohol content was not affected significantly by the source of honey. While pH of the osmotically extracted fruit honey juice decreased rapidly to pH $2.92{\sim}2.97$ after 13 days of fermentation, total titratable acidity of Tangerine and Japanese apricot honey wine were 0.30 and 0.53%, respectively. After 13 days of fermentation, reducing sugar of fruit honey wines were reduced to $2.03{\sim}2.87%$, alcohol content were reached up to 13.1 and 12.5% for Tangerine and Japanese apricot honey wine, respectively. Generally, honey extracted fruit juices were fermented more efficiently than diluted honey juice.

• Korean journal of food and cookery science
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• v.4 no.1
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• pp.59-63
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• 1988

The changes of acidity, the content of alcohol-insoluble solid (AIS) and pectic substances of Kimchis which were prepared with various garlic contents and fermentation at $21^{\circ}C$ were investigated. Acidity and the content of water soluble pectin of Kimchis increased but the content of AIS and protopectin decreased during the fermentation. As the Kimchis contained high garlic contents compared with the Kimchis deleted garlic, acidity of those rapidly increased but the content of AIS of those slightly decreased with fermentation. In the case of Kimcltis contained high garlic contents, protopectin decreased and water soluble pectin increased with fermentation, but the amount of changes was small.