• 한국조리학회지
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• 제23권1호
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• pp.95-102
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• 2017

This study was activity of ${\alpha}-amylase$, glucoamylase of liquid Nuruk prepared using liquid Nuruk (NK) and Aspergillus kawachii (AK), Aspergillus niger (AN), Aspergillus oryzae (AO), Monascus kaoliang (MK). To investigate the relationship between the enzymatic activity and the total sugar content of liquid Nuruk depending on the types of Nuruk molds and the degree of rice-polishing. The activity of ${\alpha}-amylase$ depending on the types of Nuruk molds was shown to be 8.82, 8.72 units/mL in AN and AK treatments in brown rice liquid Nuruk at 24 hours after incubation, as the degree of rice-polishing increased, the activity of ${\alpha}-amylase$ was significantly lower (p<0.05). When brown rice was incubated in AN, it showed 8.83 units/mL at 48 hours after incubation, which was the highest activity, but there was no significantly difference (p<0.05), as the degree of rice- polishing was higher, the activity of ${\alpha}-amylase$ was lower. The activity of glucoamylase depending on the degree of rice-polishing showed 3,013 units/mL in AO treatment in brown rice liquid Nuruk at 24 hours after incubation, and the enzymatic activity was significantly higher (p<0.05). As the degree of rice-polishing increased, the activity of glucoamylase decreased, so liquid brown rice Nuruk showed the highest enzymatic activity, liquid white rice Nuruk was the lowest enzymatic activity. The highest enzymatic activity appeared in liquid Nuruk with brown rice at 48 hours after incubation. The activity of ${\alpha}-amylase$, glucoamylase showed higher enzymatic productivity as the degree of rice-polishing was lower, and there was an inverse correlation with the total sugar content.

• Korean Chemical Engineering Research
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• 제51권6호
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• pp.716-726
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• 2013

가수분해 효소(혹은 아실전이효소)를 이용한 알콜과 아민의 아실반응은 에스터의 가수분해 반응(hydrolysis, deacylation)과 더불어 효소를 이용한 유기합성 반응에서 이미 잘 확립된 기술로서, 산업체에서 제약의 합성이나 고분자의 합성에서 널리 응용되고 있다. 이러한 효소를 이용한 아실화 반응은 주로 열역학적인 제한으로 인해 그동안 대부분이 주로 유기용매에서 이루어지고 있다. 최근 들어서, 수용액에서 아실화반응을 전이효소를 이용하여 효율적으로 할 수 있다는 보고와 함께 그 반응 기제에 대한 연구들이, X-ray 구조와 이러한 반응을 가능하게 하는 효소의 단백질 서열 비교 연구, 그리고 계산 화학에 의한 효소의 설계 연구등을 통해 새롭게 밝혀지고 있다. 본 총설에서는 효소를 이용한 아실화반응을 유기용매와 수용액에서의 수행함에 있어서 장단점을 비교해 보면서, 앞으로의 전망도 함께 제시하고자 한다. 특별히 다양한 천연물들의 구조 변화에 아실화 반응 생체촉매를 사용할 수 있는 가능성에 대해 살펴볼 것이다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 추계학술대회 논문집
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• pp.505-505
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• 2009

The object is to optimize the best condition of organosolv pretreatment process with sulfuric acid as a catalyst. As a material, Pitch pine (Pinus rigida) was ground and sieved through 40-mesh screen, and Celluclast and $\beta$-glucosidase were used as enzymes for enzymatic hydrolysis. Pretreatment processes were carried out in the minibomb, and 20 g of materials with 200 ml of 50% ethanol solution (v/v) with 1% sulfuric acid as a catalyst. Pretreatment temperature was varied from $150^{\circ}C$ to $190^{\circ}C$, and time was varied from 0 to 20 min. Then, residual materials were used for enzymatic hydrolysis. The best conditions were selected by estimating followed enzymatic hydrolysis rate and degradable rates after pretreatment process. The highest value of enzymatic hydrolysis rate was obtained as 55 - 60% at 160 and at $180^{\circ}C$, but the value decreased under more severe conditions. As the residual rates decreased under severe conditions, it infered that the decrease of sugar contents limits enzymatic hydrolysis rates. Combined with enzymatic hydrolysis rate, degradable rates and H-factors, the temperatures at $160^{\circ}C$ for 20 min and at $180^{\circ}C$ for 0 min were concluded as the optimized conditions where have the lowest H-factor value for considering energy input.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
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• pp.198-201
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• 2008

The electron beam irradiation was applied as a pretreatment of the enzymatic hydrolysis of yellow poplar with doses of 0$\sim$450 kGy. The higher irradiation dose resulted in the more degradation of hardwood biomass not only from carbohydrates but also from lignin. This changes originated from the irradiation resulted in the better response to enzymatic hydrolysis with commercial cellulases (Celluclast 1.5L and Novozym 342). The more improvement on enzymatic hydrolysis by the irradiation was found in the xylan than in the cellulose of yellow poplar.

• 상하수도학회지
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• 제12권2호
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• pp.115-126
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• 1998

In use of anaerobic bioconversion shellfish wastes present special problems, since the chitinous structures in the shell faction degrade very slowly in an anaerobic environment. Enzymatic pretreatment method was evaluated for improving the anaerobic bioconversion potential of blue crab processing wastes. An enzymatic pretreatment using chitinase enhanced the ultimate methane yield and biodergradation rate constant for total crab solid wastes by 15% and 19% respectively, above those of the untreated wastes. When the enzymatic pretreatment applied to the shell fraction alone, it resulted in increase of 34% in the ultimate methane yield and 38% in the reaction rate. The results indicate that anaerobic bioconversion of these wastes is technically feasible and enzymatic pretreatment will improve the efficiency of the process.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.418-421
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• 2009

Effects of aqueous ammonia soaking to three annual plants (hemp woody core, tobacco stalk and corn stover) awere investigated to focus on the enzymatic saccharification characteristics change by this treatment. At two different levels of treatment ($90^{\circ}C$-16 h and $45^{\circ}C$-6 days), higher temperature treatment led to more enzymatic saccharification of cellulose to glucose by commercial cellulase mixtures (Celluclast 1.5L and Novozym 342 from Novozyme Korea). Difference among annual plants were significant. corn stover was the best response to enzymatic saccharification of cellulose and xylan by comercial enzymes all treatment conditions but tobacco stalk was the worst response to all of them. chemical composition or physical structure difference may brought this difference.

• 생약학회지
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• 제31권2호
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• pp.240-244
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• 2000

Antimutagenicity profiles of the enzymatic browning reaction products(EBRP) were investigated. The rec-assay with Bacillus subtilis strains $H17(rec^+)$ and $M45(rec^-)$ was carried out using their spores. The biological activities were evaluated for seven different enzymatic browning reaction products, which resulted from the reactions of seven polyphenols with polyphenol oxidase isolated from Ginkgo biloba leaves. In the spore $rec^-$ assay, most of the polyphenolic compounds tested were positive, whereas their enzymatic browning reaction products were tested negative. The mutagenicity of enzymic browning mixtures of the polyphenols and the enzymes obtained from Ginkgo biloba leaves showed negative results in the mutagenicity test using Bacillus subtilis strains $H17(rec^+)$ and $M45(rec^-)$. In the case where polyphenol oxidase inhibitors were added in the enzymatic reaction mixtures with polyphenols, the polyphenols showed mutagenic effect in the spore $rec^-$ assay. This suggests that the activity of polyphenol oxidase is decreased.

• Preventive Nutrition and Food Science
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• 제21권4호
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• pp.338-347
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• 2016

The present study investigated the volatile compound, physicochemical, and antioxidant properties of beany flavor-removed soy protein isolate (SPI) hydrolyzates produced by combined high temperature pre-treatment and enzymatic hydrolysis. Without remarkable changes in amino acid composition, reductions of residual lipoxygenase activity and beany flavor-causing volatile compounds such as hexanol, hexanal, and pentanol in SPI were observed after combined heating and enzymatic treatments. The degree of hydrolysis, emulsion capacity and stability, 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity, and superoxide radical scavenging activity of SPI were significantly increased, but the magnitudes of apparent viscosity, consistency index, and dynamic moduli (G', G") of SPI were significantly decreased after the combined heating and enzymatic treatments. Based on these results, it was suggested that the enzymatic hydrolysis in combination with high temperature pre-treatment may allow for the production of beany flavor-removed SPI hydrolyzates with superior emulsifying and antioxidant functionalities.

• 펄프종이기술
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• 제32권4호
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• pp.34-40
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• 2000

This study was carried out to evaluate the effects of enzymatic treatment on the characteristics of KOCC. Novozym 342 and Pulpzyme HC were used for this purpose. Enzymatic treatment greatly increased the freeness of KOCC and Novozym 342 was more effective. WRV was improved only when KOCC was treated with 0.1% Pulpzyme HC. Pulpzyme HC was more effective to improve the flexibility of fiber(conformability angle) than Novozym 342. Coarseness of fiber was decreased with the enzymatic treatment. Fines content greatly decreased with 0.01% addition of enzymes. Novozym 342 was more effective than Pulpzyme HC for this purpose. Apparent density, tensile index and tear index decreased with enzymatic treatment, but stiffness increased. Especially the decrease of apparent density, tensile index and tear index by the treatment with Novozym 342 was significant than those of Pulpzyme HC. Therefore Novozym 342 will be suitable for the removal of fines and for bulky sheet, otherwise Pulpzyme HC will be good.

• 펄프종이기술
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• 제46권6호
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• pp.1-7
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• 2014

Dissolving part of xylan and lignin in lignocellulosic biomass by base can be used as pretreatment technique. Cork oak was pretreated with sodium hydroxide solution and the pretreatment effects were evaluated with two critical factors - NaOH concentration and pretreatment temperature. Some of xylan and lignin were removed by base pretreatment. At $90^{\circ}C$ and 13% NaOH pretreatment, 22.0% of lignin and 78.8% of xylan removed by base treatment. Enzymatic hydrolysis of cork oak which was pretreated at higher temperature or concentration was further improved. After pretreatment of cork oak with 13% NaOH at $90^{\circ}C$, the conversion rate of cellulose to fermentable sugars were reached up to 91.3%. At ethanol fermentation with enzymatic hydrolysate from different pretreatment conditions, all enzymatic saccharification liquids were well fermented by Saccharomyces cerevisiae.