• 한국응용과학기술학회지
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• 제33권4호
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• pp.627-633
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• 2016

단수수[Sorghum bicolor (L)]는 당류가 풍부한 사탕수수, 사탕무와 같은 주요 바이오연료 작물 중의 하나이다. 단수수 착즙액은 단수수 줄기를 압착하여 추출하며 주요 성분는 glucose와 fructose 그리고 sucrose로 구성되어 있다. 에탄올은 효모발효공정을 통하여 단수수 착즙액으로부터 쉽게 생산할 수 있다. 단수수 착즙액은 당류 뿐만 아니라 질소나 인산과 같은 다양한 무기영양원도 함유하고 있어 종균 배지로 활용성이 높다. 상업적인 에탄올 생산 공정에서 종균배양은 중요한 발효공정 중의 하나이며 공정비용 절감을 위해 최적화된 배지가 필수적이다. 본 연구에서는 섬유질계 바이오에탄올 생산을 위한 종균의 배지로서 단수수 착즙액의 특성을 평가하였다. 단수수착즙액의 발효기질 적합성을 평가하기 위해 YPD 및 억새 당화액을 비교하여 실험하였으며, YPD배지 중 yeast extract 와 peptone은 각각 5 g/L의 농도로 사용하였다. 각각의 기질들은 당 농도가 2%, 5%, 10%가 함유되도록 제조하여 발효를 통한 균체농도를 측정하였다. 그 결과 YPD와 단수수착즙액을 배지로 사용하였을 때 발효 24시간 후에 최대 $2.5{\times}10^8CFU/mL$ 이상의 균체농도를 나타내었다. 결과적으로 단수수착즙액은 12시간 발효 후에 $1.0{\times}10^8CFU/mL$ 균체를 생산하여 섬유질계 바이오에탄올 생산을 위한 종균 배지로서 YPD를 대체하여 사용할 수 있음을 확인하였다.

• Journal of Microbiology and Biotechnology
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• 제6권2호
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• pp.120-127
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• 1996

The characteristics of cell growth and poly-$\beta$-hydroxybutyrate biosynthesis of Alcaligenes latus ATCC 29713 were investigated. The PHB accumulation pattern of A. latus followed a growth-associated type where the cell growth and PHB accumulation were carried out simultaneously. Various intermediate compounds such as metabolites involved in the TCA cycle, amino acids, and saturated and unsaturated fatty acids were added to examine their effect on cell growth and PHB accumulation. Citrate, tyrosine, and palmitic acid showed the most significant increase both on cell growth and PHB accumulation. Maximum PHB concentrations were noticeably increased about 1.4 to 1.6 times higher than that of control, corresponding to 5.54, 6.45, and 6.45 g/l for citrate, tyrosine, and palmitic acid, respectively. The stimulatory effects of the supplemented metabolites were analyzed in terms of the increment of enzyme activities related to sugar catabolism and PHB biosynthesis.

• Food Science and Biotechnology
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• 제15권5호
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• pp.688-693
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• 2006

Glucosinolates are hydrolyzed by the enzyme myrosinase and are mainly found in cruciferous vegetables such as Chinese cabbage (Brassica campestris L. ssp. pekinensis). lsothiocyanates (ITCs) are glucosinolate degradation products with reported anticarcinogenic properties. Korean Chinese cabbage in the form of 'kimchi' is a staple part of the Korean diet. In this study, we examined the effects of storage temperature and duration on glucosinolate, ITC, soluble sugar, and organic acid levels in kimchi. Changes in pH and the impact of various parts of the Korean Chinese cabbage being used during the preparation of the dish were also assessed. Extracted ITC levels, analyzed via gas chromatography (GC) and GC/mass spectrometry (GC/MS), were higher in the midrib parts than in the cabbage leaves after storage at both 4 and $20^{\circ}C$. During storage, organic acid levels increased while soluble sugars were depleted. The pH initially increased (after 1 day at $20^{\circ}C$, and 1 week at $4^{\circ}C$), but subsequently decreased over time at both temperatures. Glucosinolate and ITC levels increased in the beginning of storage but then generally fell during further storage. Our data suggest that acidity-related reduction in myrosinase activity during storage may decrease glucosinolate and ITC levels. The changes in these levels depended on the storage conditions and the Korean Chinese cabbage parts used for the kimchi preparation.

• Asian-Australasian Journal of Animal Sciences
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• 제12권5호
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• pp.752-757
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• 1999

Studies were made of digestion of timothy (Pheleum pretense) hay, tall fescue (Festuca elatior) hay, and rice (Oryza sativa) straw in pure cultures of rumen anaerobic fungus, Neocallimastix frontails MCH3. The fungus was inoculated on ground forages (1%, w/v) in an anaerobic medium and incubated at $39^{\circ}C$. Incubation was continued for 24, 48, 72 and 96 h. The losses of dry matter, xylose and glucose of forage during incubation were determined at the end of these incubation periods. Xylose and glucose were considered to be released from xylan and cellulose, respectively. The digested xylan to digested cellulose (X/C) ratios of the substrate were calculated. Xylanase and carboxymethyl cellulose (CMCase) of culture supernatant and residual substrate was measured at the same time. The X/C ratios in the cultures on timothy hay and rice straw were greater than 0.5 in the first 24-h incubation period. The values were smaller than 0.3 in tall fesque. The ratio of xylanase activity to that of CMCase in the first 24-h incubation period correlated well with the traits in X/C ratio. However xylanase activity was still superior to CMCase in the following incubation period (48 to 96 h), although the glucose (designated as cellulose) was more intensively digested than xylose (designated as xylan). The production of these polysaccharidases appeared to correlate with substrate cell-wall sugar composition, xylose to glucose ratios, at the beginning of fast growing period.

• 동아시아식생활학회지
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• 제23권3호
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• pp.365-373
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• 2013

This study is performed to investigate the quality characteristics of sulgidduk added with cheonnyuncho fruit powder. Sulgidduk was prepared with freeze-dried cheonnyuncho, rice flour, sugar syrup and salt. The sulgidduk was made with various amounts (0, 3, 6, 9, 12%) of added cheonnyuncho fruit powder. The proximate composition, pH, Hunter's color value, texture profile analysis, sensory characteristics and SEM of cheonnyuncho sulgidduk were being examined. The addition of cheonnyuncho fruit powder has a tendency to decrease the moisture contents of sulgidduk while the crude ash, crude lipid and crude protein increased. The pH of sulgidduk decreased when the amounts of cheonnyuncho fruit powder increased. As the amount of cheonnyuncho fruit powder increased, the lightness (L) decreased, while the redness (a) and yellowness (b) increased. In texture profile analysis, the hardness decreased with increasing cheonnyuncho fruit powder contents, whereas cohesiveness, springiness, gumminess and brittleness increased. The results of sensory evaluation showed that the sulgidduk with 3%, 6% of cheonnyuncho fruit powder got the highest scores on the color, taste, springiness and acceptability. The air cells of sulgidduk observed by SEM were big and uniform with the amount of cheonnyuncho fruit powder increased. In conclusion, these results show that the quality and preference increased when 3%, 6% of cheonnyuncho fruit powder was added to the sulgidduk.

• Carbon letters
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• 제12권3호
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• pp.143-151
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• 2011

Bagasse fly ash (BFA) is one of the important wastes generated in the sugar industry; it has been studied as a prospective low-cost adsorbent in the removal of congo red (CR) from aqueous solutions. Chemical treatment with $H_2O_2$ was applied in order to modify the adsorbability of the raw BFA. Batch studies were performed to evaluate the influence of various experimental parameters such as dye solution pH, contact time, adsorbent dose, and temperature. Both the adsorbents were characterized by Fourier-transform infrared spectrometer, energy-dispersive X-ray spectrophotometer and nitrogen adsorption at 77 K. Equilibrium isotherms for the adsorption of CR were analyzed by Langmuir, Freundlich and Temkin models using non-linear regression technique. Intraparticle diffusion seems to control the CR removal process. The obtained experimental data can be well described by Langmuir and also followed second order kinetic models. The calculated thermodynamic parameters indicate the feasibility of the adsorption process for the studied adsorbents. The results indicate that BFA can be efficiently used for the treatment of waste water containing dyes.

• International Journal of Oral Biology
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• 제38권4호
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• pp.175-180
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• 2013

Xylitol is a five-carbon sugar alcohol that reduces the incidence of caries by inhibiting the growth of oral streptococci, including Streptococcus mutans. Since xylitol is transported via the fructose phosphotransferase system, we hypothesized that it could also affect the growth of other oral bacteria strains. We tested the effects of xylitol against non-periodontopathogenic oral bacteria frequently found in healthy subjects as well as periodontopathogens including Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia. With 5% xylitol, Streptococcus vestibularis and Gemella morbillorum showed marked growth inhibition. With 10% xylitol, all of the tested periodontopathogens and Actinomyces naeslundii showed marked growth inhibition, whereas the growth inhibition of Neisseria mucosa, Neisseria sicca and Veillonella parvula was mild only. Xylitol is a widely used sweetener and the concentration used in our experiment is easily achieved in the oral cavity. If xylitol reduces the growth of periodontopathogens more preferentially, it could also reduce the prevalence of these pathogens and have clinical utility in the prevention or treatment of periodontal disease.

• Bulletin of the Korean Chemical Society
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• 제26권5호
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• pp.769-775
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• 2005

An efficiency of Monte Carlo (MC) docking simulations was examined for the prediction of chiral discrimination by cyclodextrins. Docking simulations were performed with various computational parameters for the chiral discrimination of a series of 17 enantiomers by $\beta$-cyclodextrin ($\beta$-CD) or by 6-amino-6-deoxy-$\beta$-cyclodextrin (am-$\beta$-CD). A total of 30 sets of enantiomeric complexes were tested to find the optimal simulation parameters for accurate predictions. Rigid-body MC docking simulations gave more accurate predictions than flexible docking simulations. The accuracy was also affected by both the simulation temperature and the kind of force field. The prediction rate of chiral preference was improved by as much as 76.7% when rigid-body MC docking simulations were performed at low-temperatures (100 K) with a sugar22 parameter set in the CHARMM force field. Our approach for MC docking simulations suggested that the conformational rigidity of both the host and guest molecule, due to either the low-temperature or rigid-body docking condition, contributed greatly to the prediction of chiral discrimination.

• 동아시아식생활학회지
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• 제20권4호
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• pp.509-515
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• 2010

This study was performed to investigate the quality characteristics of Sulgidduk added ssukgat. Sulgidduk was prepared with freeze-dried ssukgat powder, rice flour, sugar, and salt. The Sulgidduk was made with various amounts(0, 1, 3, 5, 7%) of added ssukgat powder. The moisture content, Hunter's color value, dietary fiber, texture profile analysis, and sensory characteristics of ssukgat Sulgidduk were examined. The addition of ssukgat powder has a tendency to decrease the water content of Sulgidduk. As the amount of ssukgat powder increased, the lightness (L) and redness (a) decreased, and the yellowness (b) increased. In texture profile analysis, the hardness decreased with increasing ssukgat powder content. Chewiness, cohesiveness and springiness did not show significant differences with different amounts of ssukgat powder. The results of sensory evaluation showed that the sweetness, softness, and overall acceptability scores were the highest with Sulgidduk containing 3% ssukgat powder. In conclusion, these results show that the Sulgidduk with 3% of ssukgat powder contained dietary fiber is the best.

• 동아시아식생활학회지
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• 제21권1호
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• pp.38-45
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• 2011

This study aimed to determine the sensory acceptability of Gochujang dressing containing added Maesil (Prunus mune) concentrate. Gochujang dressing was blended with different concentrations of Maesil concentrate (0%, 1%, 2%, 3%, 4%). Moisture contents, L, a, b values, pH level, and sugar contents decreased, whereas acidity and viscosity increased with increasing Maesil contents. Salinity did not change significantly. For attribute difference test, as Maesil concentration increased, color intensity, savory flavor, sour flavor, hot taste, and mouthfeel decreased, whereas glossiness decreased. The acceptance test showed that 2% Maesil concentrate was the most preferable for appearance, taste, texture, and overall quality. In conclusion, the results indicate that addition of 2% Maesil concentrate to Gochujang dressing is optimal and provides good properties as well as reasonably high overall acceptability.