• 한국식품조리과학회지
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• 제28권1호
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• pp.51-55
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• 2012

This study was conducted to investigate the physicochemical properties of citrus peel extracts with different hot water extraction and enzymatic hydrolysis conditions. Enzymatic hydrolysis was also employed using Viscozyme L and results were compared with that of optimized hot water extract. Hot water extraction was performed under different parameters; the sample to solvent ratio(1:20, 1:15, 1:10), extraction time(2, 4 hrs), extraction temperature(85, $95^{\circ}C$) and enzymatic hydrolysis(0, 1%) and the subsequent extracts were used for determining their physicochemical properties, such as total yield, total phenolics, total flavonoids, and electron donating ability (EDA). With the increase in the sample to solvent ratio and extraction time, total yield, total phenolics, total flavonoids and EDA increased. But extraction temperature did not significantly affect the hot water extract. As hot water extract was hydrolyzed by the enzyme, total yield and active ingredients increased rapidly. In the result of total yield, total phenolics, total flavonoids and EDA, the activity of enzyme-treated extract was higher than those of enzyme-untreated extract. Based upon the overall hot water extraction efficiency, it was found that 20 times volume or 120 min at a time at $95^{\circ}C$ after enzyme treatment was optimal.

• 공업화학
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• 제25권6호
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• pp.619-623
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• 2014

산 가수분해공정과 효소당화공정을 이용하여 사과, 귤, 수박껍질로부터 셀룰로오스 에탄올을 생산하고, 그 최적조건을 결정함으로써 과일껍질을 원료로 한 바이오에너지 생산가능성을 평가하고자 하였다. 산 가수분해공정을 이용하여 과일껍질로부터 셀룰로오스 에탄올을 생산하기 위한 최적조건은 사과껍질의 경우 황산농도 20 wt%에서 90 min, 귤껍질과 수박껍질의 경우에는 각각 산 가수분해시간 60 min에서 황산의 농도가 15, 10 wt%인 것으로 나타났다. 효소당화공정을 이용하여 과일껍질로부터 셀룰로오스 에탄올을 생산할 경우 효소로는 Viscozyme이 가장 우수한 전환특성을 나타내었으며, 최적 효소당화시간은 사과껍질(180 min), 귤껍질(60 min), 수박껍질(120 min)인 것을 알 수 있었다.

• Preventive Nutrition and Food Science
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• 제10권1호
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• pp.11-16
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• 2005

Enzymatic hydrolysis of dark muscle of skipjack was optimized by using response surface methodology. Three factors of independent values were pH (4.2 to 9.8), time (0.6 to 3.4 hrs) and temperature (34℃ to 76℃), and independent values were optical density and brix. The optimum conditions for enzymatic hydrolysis were pH 7.0 to 8.0, 55℃ and 3 hrs. The headspace volatile compounds of reaction flavors using the enzymatic hydrolysate, cysteine and xylose were identified by using the combination of a canister system, gas chromatography and mass selective detector. Among 67 compounds, we identified 8 sulfur-containing compounds and 7 furans which were thought to be highly related to meat-like flavors.

• 한국미생물·생명공학회지
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• 제19권4호
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• pp.377-382
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• 1991

우지를 lipase에 의해 지방산과 글리세린으로 분해하는 반응을 액상 및 고상에서 수행하였다. 올리브유를 기질고 lipase OF 360(일본 메이토사 제품)의 특성을 조사한 결과 최적 pH는 6, 최적 온도는 $37^{\circ}C$이었다. 우지를 기질로 액상 효소반응을 수행한 결과는 물사용량 80 wt/wt, 온도 $37^{\circ}C$, 효소사용량 200unit/g tallow 조건에서 93의 가수분해율을 얻을 수 있었다.

• 한국축산식품학회지
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• 제35권3호
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• pp.350-359
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• 2015

This review focuses on the enhanced functional characteristics of enzymatic hydrolysates of whey proteins (WPHs) in food applications compared to intact whey proteins (WPs). WPs are applied in foods as whey protein concentrates (WPCs), whey protein isolates (WPIs), and WPHs. WPs are byproducts of cheese production, used in a wide range of food applications due to their nutritional validity, functional activities, and cost effectiveness. Enzymatic hydrolysis yields improved functional and nutritional benefits in contrast to heat denaturation or native applications. WPHs improve solubility over a wide range of pH, create viscosity through water binding, and promote cohesion, adhesion, and elasticity. WPHs form stronger but more flexible edible films than WPC or WPI. WPHs enhance emulsification, bind fat, and facilitate whipping, compared to intact WPs. Extensive hydrolyzed WPHs with proper heat applications are the best emulsifiers and addition of polysaccharides improves the emulsification ability of WPHs. Also, WPHs improve the sensorial properties like color, flavor, and texture but impart a bitter taste in case where extensive hydrolysis (degree of hydrolysis greater than 8%). It is important to consider the type of enzyme, hydrolysis conditions, and WPHs production method based on the nature of food application.

• Preventive Nutrition and Food Science
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• 제20권3호
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• pp.183-189
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• 2015

In the present study, an optimum protease was selected to hydrolyze the egg white liquid protein for the antioxidant peptides. Alcalase treatment yielded the highest amount of ${\alpha}$-amino groups (15.27 mg/mL), while the control (no enzymatic hydrolysis) showed the lowest amount of ${\alpha}$-amino groups (1.53 mg/mL). Alcalase also gave the highest degree of hydrolysis (DH) value (43.2%) and was more efficient for egg white liquid hydrolysis than the other enzymes. The Alcalase hydrolysate had the highest radical-scavenging activity (82.5%) at a concentration of 5.0 mg/mL. The conditions for enzymatic hydrolysis of egg white liquid with Alcalase were selected as substrate : water ratio of 2:1. Five percent Alacalse treatment did not show significant (P>0.05) increases of DH and ${\alpha}$-amino nitrogen content after 24 hhydrolysis. Thirty two hour-hydrolysis with 5% Alcalase is sufficient to make antioxidative egg white liquid hydrolysate from egg white liquid. DPPH and ABTS radical-scavenging activities were significantly (P<0.05) higher after enzymatic digestion. These results suggest that active peptides released from egg-white protein are effective radical-scavengers. Thus, this approach may be useful for the preparation of potent antioxidant products.

• Biotechnology and Bioprocess Engineering:BBE
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• 제3권1호
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• pp.35-39
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• 1998

An enzymatic process was developed to produce protein hydrolysater form defatted soya protein. Various unit operations were tried, and the effects of pre- and post-treatments on the product characteristics such as degree of hydroylsis (DH), free amino acid content (%FAA) and average molecular weight (MW) were investigated. The use of acid washes showed no difference in %DH. Increasing pH during pre-cooking gave lower %DH. Alkaline cooking made too much insoluble protein, thus the protein yield was too small. A better hydrolysis with more acceptable taste was obtained when the combination of Neutrase/Alcalase/Flavourzyme was used in place of Alcalase/Flavourzyme combination; Untoasted defatted soya was more effective on the proteolysis than toasted one. The MW of the evaporated and spray dried product was higher than that of undried product, due to precipitation of low-solubility components. When ultrafiltration and the product concentration carried out the product separation by reverse osmosis, the solubility and the taste of the product were improved. The difference between enzyme hydrolysate and acid hydrolysate was significant in free amino acid composition, especially in tyrosine, phenylalanine, glutamine and asparagine.

• Journal of the Korean Wood Science and Technology
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• 제21권3호
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• pp.53-60
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• 1993

Substrates used were hardwood-Suwon poplar-(Populus alba${\times}$glandulosa L.) and softwood-pitch pine-(Pinus rigida M.). And these substrates were steam exploded then treated with sodium chlorite at 75$^{\circ}C$ with occasional stirring in order to obtain samples which had different lignin contents and crystallinity. And then this resulting samples incubated with a commercial cellulase derived from Trichoderma ressei. The contents of Klason lignin were decreased as the increasing of the ratio of sodium chlorite in the two species. The effect of hardwood was more effective than that of softwood in the same ratio of sodium chlorite. The minimum contents of Klason lignin were 0.8% and 5.1% respectively. And the crystallinities of cellulose were increased very little as increasing of the ratio of sodium clorite. The hydrolysis extent of the two species were increased as the increasing of delignification. Especially, the hydrolysis extent of hardwood was more higher than that of softwood. The maximum hydrolysis extent were 89.8% and 71.1%, respectively.

• Korean Chemical Engineering Research
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• 제54권1호
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• pp.70-74
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• 2016

본 연구에서는 창자파래(Enteromorpha intestinalis)로부터 citrate buffer를 사용하여 전처리 조건(고액비, 반응온도, buffer의 pH와 농도)에 따른 전처리 반응과 효소가수분해를 통한 가수분해 수율을 조사하였다. 0.25 M, pH 3.5의 citrate buffer를 이용하여 $140^{\circ}C$에서 60분간 전처리를 수행한 결과, 5.40%의 가수분해 수율을 얻었다. 최종적으로 전처리 반응 후 24시간의 효소 가수분해를 통하여 18.68%의 가수분해 수율을 얻었다. 이 결과는 대조구에 비하여 약 1.81배 증가한 결과이다.

• 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.