• Journal of Microbiology and Biotechnology
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• v.18 no.6
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• pp.1141-1145
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• 2008

Isomaltooligosaccharide (IMO) is a promising dietary component with prebiotic effect, and the long-chain IMOs are preferred to short chain ones owing to the longer persistence in the colon. To establish the optimal process for synthesis of long-chain IMOs, we systematically examined the reaction condition of dextransucrase of Leuconostoc mesenteroides B-512F by changing the ratio of sucrose to maltose (varying as 1:4, 1:2, 1:1, and 2:1) and amount of each sugar (from 2% to 20%). As a result, a ratio of 2:1 (sucrose to maltose, 10:5% or 20:10%, w/v) was determined as an optimal condition for long-chain IMO synthesis (DP3-DP9) with relatively higher yields (70-90%, respectively).

• Journal of Microbiology and Biotechnology
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• v.27 no.1
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• pp.77-83
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• 2017

Lignocellulosic biomass represents a potentially large resource to supply the world's fuel and chemical feedstocks. Enzymatic bioconversion of this substrate offers a reliable strategy for accessing this material under mild reaction conditions. Owing to the complex nature of lignocellulose, many different enzymatic activities are required to function in concert to perform efficient transformation. In nature, large multienzyme complexes are known to effectively hydrolyze lignocellulose into constituent monomeric sugars. We created artificial complexes of enzymes, called rosettazymes, in order to hydrolyze glucuronoxylan, a common lignocellulose component, into its cognate sugar ${\small{D}}$-xylose and then further convert the ${\small{D}}$-xylose into ${\small{D}}$-xylonic acid, a Department of Energy top-30 platform chemical. Four different types of enzymes (endoxylanase, ${\alpha}$-glucuronidase, ${\beta}$-xylosidase, and xylose dehydrogenase) were incorporated into the artificial complexes. We demonstrated that tethering our enzymes in a complex resulted in significantly more activity (up to 71%) than the same amount of enzymes free in solution. We also determined that varying the enzyme composition affected the level of complex-related activity enhancement as well as overall yield.

• Journal of the Korean Society of Food Culture
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• v.8 no.4
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• pp.331-335
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• 1993

This study was performed to improved the quality of dried persimmon. For this, the investigation of quality factor and processing experiments were performed. The moisture contents of dried persimmons were 30 to 36% and it was the most important component of the quality. Tannin contents were 0 to 20% and non-treated persimmon had higher tannin contents than treatment of carbon dioxide and alcohol. Total sugar contents were 55 to 60% and it was composed in glucose and fructose. Processing of dried persimmon by artificial-drying seemed to be useful when it needed to shorten the drying time or it continued rainy day during sun-drying. From the result of quality evaluation, sliced dried persimmon was better than whole dried persimmon in quality, so the sliced dried persimmon was expected that it has a little marketability.

• Journal of the Korean Society of Food Culture
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• v.29 no.6
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• pp.637-647
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• 2014

This study was conducted to examine the physicochemical properties and consumer acceptability of commercial Gang-jeong. The samples used in this study were nine different Gang-jeong as commercial products. To accomplish this research, the physicochemical properties of nine samples, including moisture, crude lipid, sugar contents, acid value, color values, and texture, were measured. In addition, consumer panels evaluated the overall acceptability, appearance, flavor, sweetness, and texture of samples using a 9-point Likert type scale as well as the perceived intensities of sweetness and rancid odor by a 9-point Just-About-Right (JAR) scale. All data were statistically analyzed using One-way ANOVA, Principle Component Analysis, Hierarchical Cluster Analysis, and Pearson's Correlation Analysis. All physicochemical properties were significantly different among the samples (p<0.001). Analyses of consumer acceptability and JAR ratings of the nine samples showed significant differences (p<0.001).

• Journal of the Korean Society of Food Culture
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• v.28 no.1
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• pp.99-106
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• 2013

The effects of stevioside-containing sweetener (SCS) on kimchi quality were evaluated by investigating acid production, growth of lactic acid bacteria, sensory properties, and several volatile odor component (VOC)s of SCS-added kimchi. The concentrations of SCS added to kimchi instead of 1% white sugar were 0.165, 0.33, 0.66, and 1.32% (w/w). The pH of kimchi with higher amounts of added SCS generally increased, and the acidity of kimchi with higher amounts of added SCS generally decreased. Addition of higher amounts of SCS generally inhibited the growth of lactic acid bacteria in kimchi. Scores of overall acceptability for 0.33 or 0.66% SCS-added kimchi were significantly higher than those for other samples (p<0.05), whereas those for 1.32% SCS-added kimchi were significantly lower than those for other samples (p<0.05). The optimum concentration of SCS added to kimchi appears to be 0.33%. Among major VOCs identified in kimchi, the concentrations of seven components including ethanol generally decreased with addition of higher amounts of SCS, whereas that of diallyl disulfide was not changed markedly. The major VOCs contributing to desirable sensory properties of kimchi were likely dimethyl disulfide and diallyl sulfide.

• Korean Journal of Microbiology
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• v.14 no.2
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• pp.84-94
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• 1976

Cellulase components, CMCase(Cx) and Avicelase$(C_1)$, were partially prueified, from the culture extract of a strain of Trichoderma koningii by column chromatography on DEAE-Sephadex A-50 and the step of gel filtration through Sphadex G-150, Optimum pH of CMCase was 5.2 and Avicelase showed the highest activity at pH 5.6 in acetate buffer. Optimal temperatures for activities of CMCase and Avicelase were $50^{\circ}C\;and\;60^{\circ}C, $ respectively. More than 70% of the activities of two enzymes were remained after heating at $60^{\circ}C$ for 30 min and Avicelase is more stable than any other fungal enzymes. The Michaelis constants, Km, of CMCase and Avicelase were 0.116% of CMC and 0.281% of avicel. And also the values of maximum velocity, Vmax, of CMCase and Avicelase were $23.20{\mu}g\;and\;2.54{\mu}g$ of reducing sugar per min. Of the metal ions tested against the activites of CMCase and Avicelase, $Cu^{++}, \; Hg^{++}, \;and\;Pb^{{++}$ are remarkably effective inhibitors. The molecular weights of Cx and $C_1$ component were estimated to be about 47, 000 and 61, 000 by gel filtration method.

• Analytical Science and Technology
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• v.8 no.4
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• pp.901-906
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• 1995

Studies on the chemical constituents from a Korean wild mushroom, Phellinus ribis, were carried out. A triterpenoid, two peroxysterols, and a chlorobenzene compound were isolated from the hexane soluble fraction of the methanol extract of dried fruiting bodies of the basidomycetes. Those compounds identifed were 3-hydroxy-20(29)-lupen-28-oic acid (betulinic acid), 5,8-epidioxyergosta-6,22-dien-3-ol(ergosterol peroxide), 5,8-epidioxyergosta-6,9(11),22-trien-3-ol (dehydroperoxyergosterol), and 1,2,4,5-tetrachloro-3,6-dimethoxybenzene. Structural studies were carried out on molecular species of a ceramide and cerebroside isolated from the chloroform soluble fraction of the methanol extract. For ceramide, the major component fatty acids were a-hydroxy fatty acid isomers of $C_{22:00}{\sim}C_{25:00};$ the predominant long-chain bases were trihydroxy sphinganine of $C_{17}{\sim}C_{18}$. The structure of a cerebroside containing mono-sugar was assumed that the long-chain base was $C_{19:2}$ sphingadienine; the major fatty acids were $C_{16}{\sim}C_{15}$ ${\alpha}$-hydroxy fatty acid isomers.

• The Korean Journal of Food And Nutrition
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• v.12 no.3
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• pp.226-232
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• 1999

To evaluate the characteristics of modified nuruk made by inoculation and cultivation of Rhizopus jap-onicus T2, Aspergillus oryzae L2 and hansenula sp. BC26 three different Takju mashes were made with modified Nuruk commercial Nuruk and rice koji and the changes in microorganisms and major compon-ents of mashes were investigated uring brewing. The numbers of yeast kept higher in the mash of mod-ified Nuruk or rice koji. The numbers of lactic acid bacteria were high in mash of commercial Nuruk but those were not in mash of modified Nuruk or rice koji. all mashes showed stable pH in a day and the pH kept higher in mash of modified Nuruk than in that of commer-cial Nuruk or rice koji. Increase in the content of total acid was moderate in mash of modified Nuruk or rice koji but it was too much in that of commercial Nuruk. increase in the content of amino acid was much highr in mash of modified Nuruk or commercial Nuruk than in that of rice koji. Increase in the content of alcohol was more rapid in mash of modified nuruk or rice koji than in that of commercial Nur-uk. The content of reducing sugar kept highter in mash of commercial Nuruk or modified Nuruk than in that of rice koji. A small amount of modified Nuruk accomplished favorable fermentation showing nor-mal patterns in microbiological and physicochemical changes during brewing.

• Food Science and Biotechnology
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• v.18 no.1
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• pp.53-59
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• 2009

This study was performed to investigate the taste composition and antioxidant properties of cheonggukjang containing Korean red ginseng (RGC), as compared to either general cheonggukjang (GC) or non-fermented boiled soybeans (BS). Amylase activity was the highest (576.7 unit/g) in RGC, whereas protease activity was the highest (326.0 unit/g) in GC. The total soluble sugar contents of BS, GC, and RGC were 2,027.5, 905.5, and 837.5 mg/100 g, respectively. RGC had the highest amount of total amino acids (2,127.4 mg/100 g) and essential amino acid (50.9%) among the samples. The ratio of sweet to bitter components was higher in RGC than in GC. Although the extracts of RGC had higher radical scavenging activity for 1,1-diphenyl-2-picrylhydrazyl (DPPH) than BS or GC, regardless of the extract concentration, the ethanol extract of RGC showed the highest scavenging ability (92.4%) at 2.0 mg/mL. The chloroform extracts from GC and RGC showed their greatest superoxide dimutase-like activities at 17.2 and 19.7% at a concentration of 2 mg/mL, respectively. Regardless of the samples, the nitrite scavenging ability was positively correlated to the extract concentration, and RGC had highest ability among samples under the same extract concentrations.

• The Korean Journal of Food And Nutrition
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• v.7 no.3
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• pp.159-168
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• 1994

From the hot water extract of bracken(Pteridium aquilinum var. latiusculum), a Korean win edible plant, anti-complementary acidic polysaccharides were Isolated. Crude polysaccharide fraction(HPA-1) was obtain ed by methanol reflux, ethanol precipitation, dialysis, and lyophilization. HPA-1 contained 81.80% of total sugar, 30.40% of uronic acid, and 15.60cA of protein. HPA 1 was purified consecutively by cetavlon fractionation and chromatography including ion exchange nth DEAE-Sepharose CL 6B and gel permeation with Sephadex G-100 and Sepharose CL-6B. HPA-2- IVa and HPA-Va-2 were nearly homogeneous on HPLC and had 500,000 and 560,000 daltons of molecular weights, respectively. HPA-2-Wa consisted of fucose, galacturonic acid, and glucuronic acid at the molar ratio of 1.40 : 0.97 : 1.88. HPA-2-Va 2 was composed of rhamnose, galactose, and galacturonic acid at the molar ratio of 1.00 : 1.38 : 1.39. The polysaccharides were found to activate the C3 component both In the presence and In the absence of Ca2+ through the crossed-immunoelectrophoresis suggesting that those Involved in both classical and alternative complement pathway.