• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.239-242
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• 2002

We have synthesized branched oligosaccharides (BOS) by the mixed-culture fermentation (MBOS), fructosyltransferase (FBOS) or glucosyltransferase (GBOS) with high concentration of sucrose (3M). MBOS was further modified as iron and sulfate-oligosaccharides. The modified MBOS were stable at high temperatures (up to $140^{\circ}C$) and low pHs (2 to 4). Most highly branched and modified oligosaccharide (0.34%, w/v) effectively inhibited fructose release from sucrose by Streptococcus mutans 6715 mutansucrase. FBOS, GBOS, iron-MBOS inhibited the mutansucrase activities from Streptococcus sobrinus about 46.8%, 49.2% and 43.1%, respectively. Most highly branched and modified oligo- saccharides (0.5%, w/v) effectively inhibited the fonnation of insoluble glucan and adherence of S. mutans or S. sobrinus cell in the presence of sucrose. Modified oligosaccharides affected the growth and acid production of oral pathogens. Cytotoxicity test showed that highly branched and modified oligosaccharides was non-toxic.

• Food Science and Preservation
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• v.15 no.2
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• pp.317-324
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• 2008

This study investigated the effect of 12 different commercial yeast strains on the characteristics of fermentation and wine quality. All yeast strains had more rapid fermentation at higher temperatures. Wines fermented with the AR2, EC-1118, Premier Cuvee, and RC212 strains had faster sedimentation rates than wines fermented with the other strains. Wines fermented with EC-1118, Montrachet, and Primeur had low titratable acidity whereas wines fermented with D47 and VR5 had high titratable acidity. There was a correlation (r = 0.826) between tannin content and wine redness. Wines fermented with Fermivin, Montrachet, Primeur, VR5, Noble, and Merit strains produced lower levels of sulfur dioxide during fermentation. Wines fermented with D47, K1V-1116, AR2, and VR5 had high concentrations of glycerol, a compound known to add to "mouth feel". Wines fermented with the Fermivin, Montrachet, and Noble strains had lower concentrations of volatile acids than wines fermented with the other strains.

• Journal of the Korean Wood Science and Technology
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• v.41 no.6
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• pp.507-514
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• 2013

In this study, oxalic acid pretreatment of empty fruit bunch (EFB) was performed at different pretreatment temperatures. Also, we evaluated oxalic acid recovery from hydrolysate by electrodialysis. The fermentable sugar concentration in hydrolysate was high at more than $20g/{\ell}$, when pretreatment was carried out at $150^{\circ}C$. At the same time, ethanol production was $3.78g/{\ell}$ after 72 h which correspond to the ethanol yield of 0.21 g/g. On the other hydrolysate (160, $170^{\circ}C$), fermentable sugar was not consumed by Pichia stipitis during fermentation. Most of the oxalic acid was recovered and some of the fermentation inhibitors were removed by electrodialysis. For the electrodialysis treated hydrolysate, ethanol production was increased compared to the original hydrolysate. The highest ethanol production was $5.38g/{\ell}$ after 24 h which correspond to the yield of 0.33 g/g. The ethanol production by simultaneous saccharification and fermentation (SSF) under all pretreatment conditions was more than $15g/{\ell}$ after 96 h. The highest ethanol production was $20.54g/{\ell}$, when pretreatment was performed at $170^{\circ}C$. In particular, ethanol production was increased, when electrodialysis treated hydrolysate was used for SSF.

• The Korean Journal of Mycology
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• v.49 no.2
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• pp.199-209
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• 2021

The present study was performed to improve the technique used for fermenting the mushroom growth medium. Taxonomic analysis of 16S rDNA sequence from the predominant Bacillus strain CY-24 isolated during the fermentation phase of the rice straw medium identified it as Bacillus licheniformis. In addition, the growth environment of B. licheniformis was also examined in this study, which revealed the optimal growth temperature and pH to be 30 ℃ and 6.0, respectively. This study also revealed that carboxymethyl cellulase (CMCase) and polygalacturonase (PGase) enzymes isolated from B. licheniformis achieved their maximal activities at 50 ℃ and 60 ℃ respectively. Furthermore, the study confirmed that the two enzymes, i.e., CMCase and PGase in B. licheniformis are stable at temperatures above 60 ℃. The present study thus demonstrates that B. licheniformis CY-24 possesses excellent enzymatic properties. It also reveals that the action of enzymes during the production of growth mediums used for the cultivation of mushrooms is closely associated with the promotion of fermentation and softening of the rice straw. Overall, this study provides elementary information regarding the role of B. licheniformis enzymes during growth medium fermentation for Agaricus bisporus cultivation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.4
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• pp.56-66
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• 2021

In this study, a waste heat recovery system was devised and the performances of components incorporated to recover the heat generated during the processing of aerobic liquid-composting in a livestock manure treatment facility were analyzed. In addition, the availability of recovered heat was confirmed. The heat generated by liquid fermentation in the livestock manure treatment facility was also checked. Experimental temperatures were set at 35, 40, and 45 ℃ based on considerations of the uniformity of aerobic liquid-composting fermentation tank temperature and its operating range (34.5 ~ 43.9 ℃). Recovered heat energies from the combined heat exchanger, which consisted of PE and STS pipes, were 53.5, 65.6, 74.4 MJ/h, The heat pump of capacity 5 RT was heated at 95.6, 96.1, 98.9 MJ/h and the heating COPs of the pump were 4.53, 4.62, and 4.65, respectively. The maximum hot water production capacity of the heat exchanger assuming a fermentation tank temperature of 45 ℃ confirmed an energy supply of 56 360 kcal/day. The heating capacity of the FCU linked to the heat storage tank was 20.8 MJ/h, and the energy utilization efficiency was 96.1%. When livestock manure was dried using the FCU, it was confirmed that the initial function rate was reduced by 50.5 to 45.8 % after drying.

• Journal of The Korean Society of Grassland and Forage Science
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• v.42 no.4
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• pp.276-285
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• 2022

This study evaluated the effect of lactic acid bacteria (LAB, a mixture of Enterococcus faecium and Lactobacillus plantarum) supplementation, the storage temperature, and storage period on the fermentation characteristics and in vitro ruminal digestibility of a total mixed ration (TMR). The TMR was prepared into two groups, namely, CON (control TMR without the LAB) and ML (supplementing a mixture of E. faecium and L. plantarum in the ratio of 1% and 2% (v/w), respectively). Both groups were divided and stored at 4℃ or 25℃ for 3, 7, and 14 d fermentation periods. Supplementing LAB to the TMR did not affect the chemical composition of TMR except for the lactate and acetate concentration. Storage temperatures affected (p<0.05) the chemical composition of the TMR, including pH, lactate, and acetate contents. The chemical composition of TMR was also affected (p<0.05) by the storage period. During in vitro rumen fermentation study, the ML treatment showed lower (p<0.05) dry matter digestibility at 24 h incubation with a higher pH compared to the CON. There was no difference in the in vitro dry matter digestibility (IVDMD) of TMR between the CON and ML treatment however, at 24 h, ML treatment showed lower (p<0.05) IVDMD with a higher pH compared to the CON. The effects of storage temperature and period on IVDMD were not apparent at 24 h incubation. In an in vivo study using Holstein steers, supplementing LAB to the basal TMR for 60 d did not differ in the final body weight and average daily gain. Likewise, the fecal microbiota did not differ between CON and ML. However, the TMR used for the present study did include a commercial yeast in CON, whereas ML did not; therefore, results were, to some extent, compromised in examining the effect of LAB. In conclusion, storage temperature and period significantly affected the TMR quality, increasing acetate and lactate concentration. However, the actual effects of LAB supplementation were equivocal.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.5
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• pp.657-664
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• 2019

Objective: This study was performed to evaluate whether cold ambient temperature and dietary rumen-protected fat (RPF) supplementation affect growth performance, rumen fermentation, and blood parameters in Korean cattle steers. Methods: Twenty Korean cattle steers (body weight [BW], $550.6{\pm}9.14kg$; age, $19.7{\pm}0.13months$) were divided into a conventional control diet group (n = 10) and a 0.5% RPF supplementation group (n = 10). Steers were fed a concentrate diet (1.6% BW) and a rice straw diet (1 kg/d) for 16 weeks (January 9 to February 5 [P1], February 6 to March 5 [P2], March 6 to April 3 [P3], and April 4 to May 2 [P4]). Results: The mean and minimum indoor ambient temperatures in P1 ($-3.44^{\circ}C$, $-9.40^{\circ}C$) were lower (p<0.001) than those in P3 ($5.87^{\circ}C$, $-1.86^{\circ}C$) and P4 ($11.18^{\circ}C$, $4.28^{\circ}C$). The minimum temperature in P1 fell within the moderate cold-stress (CS) category, as previously reported for dairy cattle, and the minimum temperatures of P2 and P3 were within the mild CS category. Neither month nor RPF supplementation affected the average daily gain or gain-to-feed ratio (p>0.05). Ruminal ammonia nitrogen concentrations were higher (p<0.05) in cold winter than spring. Plasma cortisol concentrations were lower (p<0.05) in the coldest month than in the other months. Serum glucose concentrations were generally higher in colder months than in the other months but were unaffected by RPF supplementation. RPF supplementation increased both total cholesterol (p = 0.004) and high-density lipoprotein (HDL) concentrations (p = 0.03). Conclusion: Korean cattle may not be significantly affected by moderate CS, considering that the growth performance of cattle remained unchanged, although variations in blood parameters were observed among the studied months. RPF supplementation altered cholesterol and HDL concentrations but did not affect growth performance.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.5
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• pp.744-751
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• 1995

Effect of licorice root(Glycyrrhiza Uralensis Fischer) on the Dongchimi(watery radish kimchi) fermentation was investigated by measuring physicochemical, microbiological and sensory properties during fermentation up to 41 days. Dongchimi with the various levels(0, 0.5, 1.0, 1.5%) of licorice root was fermented at two temperatures : Group A was fermented at $10^{\circ}C$ and group B was fermented at $4^{\circ}C$ after keeping at room temperature($16{\pm}0.5^{\circ}C$) for 24 hours. During the fermentatiion, pH was slowly lowered in all Dongchimi samples and pH of Dongchimi added licorice root was a little higher than that of Dongchimi without licorice root. Total acidity of group A was slightly larger than that of group B and Dongchimi added licorice root showed small content than that of Dongchimi without licorice root. Reducing sugar content was reached maximum value in 13 days of fermentation in Dongchimi added licorice root of group A and B, group A decreased remarkably in 32 days of fermentation in all samples and group B was maintained in the rest sample except for Dongchimi without licorice root and Dongchimi added 1.5% licorice root. Total vitamin C of Dongchimi added licorice root was slightly higher than that of Dongchimi without licorice root of two groups. Lightness lowered gradually with the fermentation and Dongchimi without licorice root decreased a little than that of Dongchimi added licorice root. The number of lactic acid bacteria in Dongchimi added licorice root was more numerous than that of Dongchimi without licorice root. As a result of the sensory evaluation, group B showed higher scores than group A and Dongchimi added 0.5% licorice root was the most preferable one.

• Korean Journal of Food Science and Technology
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• v.40 no.6
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• pp.661-668
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• 2008

This study was investigated to determine the conditions for an auto-aging system placed within a kimchi refrigerator for optimal fermentation, as well as the optimal conditions for the prolongation of dongchimi storage time. Various fermentation characteristics of dongchimi stored at different temperatures ($5-23^{\circ}C$) were compared. The pH and acidity of dongchimi associated with the highest levels of overall acceptability were $3.9{\pm}0.1$ and $0.25{\pm}0.05%$, respectively. In order to establish the time point for the conversion of fermentation to storage, dongchimi was fermented at $10^{\circ}C$ or $15^{\circ}C$ until the acidity reached the designated points (0.1, 0.2, and 0.3%), and was then stored at $-1^{\circ}C$ for 1 week. According to the sensory evaluation, the dongchimi acidity of 0.2% fermented at $10^{\circ}C$ evidenced the highest levels of overall acceptability after 1 week of storage among the samples. In conclusion, we suggest conditions of $10^{\circ}C$ and $-2.5{\pm}0.5^{\circ}C$ for the fermentation and storage temperature, respectively, and a dongchimi acidity of 0.2% as an index for the time point for the conversion of fermentation to storage in the kimchi refrigerator.

• Journal of the East Asian Society of Dietary Life
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• v.16 no.4
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• pp.429-437
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• 2006

The quality of Jeung-pyun made with frozen rice batter was evaluated according to variations in the freezing temperature of the batter. The physicochemical sensory and rheological characteristics of Jeung-pyun were analyzed. The rice batter was stored at -20$^{\circ}C$, -40$^{\circ}C$, and -70$^{\circ}C$ for up to 4 weeks. Statistical data analysis was completed using the SAS program. The pH, and brix percentage of Jeung-pyun batter decreased during the fermentation. In carbon dioxide evolution during fermentation, the levels of the sample stored at -40$^{\circ}C$:, and -70$^{\circ}C$ for 3$\sim$4 weeks were significantly higher than that of the sample stored at -20$^{\circ}C$. The Jeung-pyun moisture content was not significantly affected by freezing temperature or storage times. Specific volume of Jeung-pyun made with rice batter stored at -40$^{\circ}C$, and -70$^{\circ}C$ for 4 weeks was significantly higher than that stored at -20$^{\circ}C$. In sensory evaluation of the stored sample for 4 weeks, the overall quality of Jeung-pyun was not significantly different between with the control and the -20$^{\circ}C$ sample, and between the control and the -40$^{\circ}C$ sample. Among the rheological properties measured with a rheometer on Jeung-pyun made with batter stored sample for 4 weeks at -20$^{\circ}C$, -40$^{\circ}C$ and unfrozen batter, the hardness was increased over the storage time, but the difference was not significant. In conclusion, the most suitable freezing temperature of the rice batter for the manufacture of Jeung-pyun was proposed to be -40$^{\circ}C$.