• Journal of Nutrition and Health
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• 제26권8호
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• pp.998-1005
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• 1993

This study was attempted to investigate the effects of enzymatic modification of milk protein with Meju protease on its acid clotting and digestibility. The proteases used in this study were isolated from Meju(fermented soybeans) and had specific acticity of 250 units/mg protein at pH 7.0. These proteases were found to be at least 3 different isoenzymes of different pH optima(pH 4.0, 6.0, 10.0). The optimum temperature was 5$0^{\circ}C$. Hydrolyzed skim milk showed 30.5% degree of hydrolysis for 1 hr. and 36.4% degree of hydrolysis for 3.5 hrs. of protease treatment at pH 7.0. Upon acidification to pH 4.0, skim milk produced large and dense coagulum, but the coagulum was getting smaller by protease treatment. Generally, digestability of skim milk at pH 4.0 was lower than pH 2.0. At pH 4.0, native skim milk and control group had problem with hydrolysis of skim milk protein. Among protease treated groups, 1 hour treated skim milk was most effectively hyrolyzed at pH 4.0.

• Biotechnology and Bioprocess Engineering:BBE
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• 제7권6호
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• pp.367-370
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• 2002

Candida cylindracea lipase was immobilized by adsorption on acid washed glass beads. It was observed that protein loading of the support depends on the size of the particle, with smaller particle containing higher amount of protein per unit weight. Initial reaction rate linearly varied up to enzyme concentration of 17.25 U/mL. Amount of free fatty acids produced was linearly proportional up to the enzyme loading of 1650 $\mu$g/g of bead. Achievement of chemical equilibrium took longer time in the case of less protein loading. Degree of hydrolysis was found to decrease in second and third consecutive batch operations on repeated use of immobilized lipase.

• 한국식품조리과학회지
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• 제20권3호
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• pp.265-270
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• 2004

To investigate the formation of pyrazines, by-products of chicken were hydrolyzed by protease/peptidase for 4, 8 and 24 hours, after which the hydrolysates were heated with glucose, fructose and xylose, respectively, at l80$^{\circ}C$ for l00min. The formation of pyrazines showed a significant difference by quality and quantity according to the degree of protein hydrolysis. Especially, the formation of 2-methyl pyrazine and 2-ethyl-5-methyl pyrazine was considerably affected by, the degree of protein hydrolysis. Also, 3-ethyl-5-methyl pyrazine, 2-butyl-3-methyl pyrazine, 2-butyl-3,5-dimethyl pyrazine, methyl pyrazine, and 3-ethyl-5-methyl pyrazine were identified only in the hydrolysates for 24 hours.

• Food Science and Biotechnology
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• 제17권4호
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• pp.873-877
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• 2008

Native soy protein isolate (SPI) was hydrolyzed with 4 different proteolytic enzymes, including bromelain, papain, Neutrase, and Flavourzyme. SPI hydrolysates with the degree of hydrolysis (DH) in range of 6 to 15% were prepared by each enzyme. The angiotensin 1 converting enzyme (ACE) inhibitory and the antioxidant activities of the SPI hydrolysates, such as superoxide dismutase-like activity and inhibition of the linoleic acid autoxidation, were evaluated. Overall, as the DH increased, all evaluated bioactivities of the SPI hydrolysates significantly increased. The significantly highest ACE inhibitory and antioxidant activities were found in hydrolysates made with papain and bromelain, respectively. SPI hydrolysates by Flavourzyme showed the significantly lowest activity in all tested bioactivities. The results suggested that ACE inhibitory and antioxidant activities of SPI hydrolysates were determined by the DH and by the enzyme used.

• 한국미생물·생명공학회지
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• 제20권1호
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• pp.46-52
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• 1992

농축유청으로부터 유청음료 제조를 위한 최적조건을 조사하기 위해 역삼투장치(reverse osmosis system)를 사용하여 치즈유청 속의 유당을 농축한 수 $\beta$-D-glactosidase로 가수분해시켜 그 분해정도를 HPLC(high performance liquid chromatography)로 측정하였다. 유당의 가수분해 정도는 농축적 유청, 2배 농축 유청과 3배 농축 유청 순으로 가수분해되었고 일정량의 효소첨가에 의해 농축된 염이 $\beta$-D-Galactosidase에 대한 약간의 저해작용을 일으켰다.

• 한국응용과학기술학회지
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• 제33권1호
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• pp.176-185
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• 2016

연산오계는 오래전부터 건강기능 증진 및 치료 효능이 높은 것으로 알려져 왔다. 최근 건강기능식품 소재로 기능성 펩타이드 효능이 알려짐에 따라, 연산오계 다리육으로부 올리고 펩타이드 최적 생산 공정 및 생성물 특성에 대하여 연구를 수행하였다. 최적 효소가수 분해 공정 표면반응 분석을 이용하여 수행하였다. 최적 공정 조건을 확립하기 위해서 온도 (40, 50, $60^{\circ}C$), pH (pH 6.0, 7.0, 8.0), 효소 (1, 2, 3%) 범위에서 수행을 하였다. 생성물에 대한 가수분해도, 유리아미노산, 분자량 분포를 분석하였다. 효소 가수분해 최적 온도는 $58^{\circ}C$, pH 7.5, 효소의 농도는 3% 이었다. 최적 조건에서 2 시간 효소 가수분해를 한 결과 75-80% 이었다. 유리 아미노산 총량은 168.131 mg/100 g 이었다. 분자량를 MALDI-TOF 으로 분석을 한 결과 90% 이상이 300-1,000 Da 분포를 보여주었다.

• 한국식품영양과학회지
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• 제27권6호
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• pp.1110-1116
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• 1998

To determine the optimum conditions for the enzymic hydrolysis against wheat gluten of high con centrations (6~14%, w/w, protein), a hydrolysis system combining weak acid pretreatment and enzymic hydrolysis was investigated. Alcalase showed the highest DH(degree of hydrolysis) of the tested proteases. After hydrolysis by alcalase, subsequently peptidases were applied for the better DH of the wheat gluten hydrolyzate. Peptidase NP2 showed the highest DH of the tested peptidases, but flavour zyme was shown for the lowest bitter taste of the resulting hydrolyzate. In order to minimize aggregation or gelling at higher initial substrate concentration during heat treatment, wheat gluten suspension was pretreated with possibly low concentrations of hydrochloric acid at 105oC for 1 hour, and then enzy matically hydrolysed with alcalase and subsequently with flavourzyme. Each required minimum concen tration of hydrochloric acid in the wheat gluten suspension of 6, 8, 10, 12, and 14%(w/w, protein) was 0.10, 0.15, 0.20, 0.225, and 0.275N, respectively. After the subsequent enzymic treatment by alcalase and peptidase NP2 for 24 hrs, the nitrogen solubility in the final wheat gluten hydrolysates was increased to 94.9, 86.4, 85.3, 89.3 and 95.0%, and their amino nitrogen content was increased to 2.87, 5.68, 7.34, 9.71 and 12.50mg/m, respectively.

• 펄프종이기술
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• 제41권5호
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• pp.26-32
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• 2009

As a part of utilizing the nanocellulose (NC) from lignocellulosic components of wood biomass, this paper reports preliminary results on the products of sulfuric acid hydrolysis. The purpose of this study was to investigate the morphology of both NC and micro-sized cellulose fiber (MCF) isolated by acid hydrolysis from commercial microcrystalline cellulose (MCC). Field emission.scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) were employed to observe the acid hydrolysis suspension, NC, and MCF. The electron microscopy observations showed that the acid hydrolysis suspension, before separation into NC and MCF by centrifugation, was composed of nano-sized NCs and micro-sized MCFs. The morphology of isolated NCs was a whisker form of rod-like NCs. Measurements of individual NCs using TEM indicated dimensions of 6.96$\pm$0.87 nm wide by 178$\pm$55 nm long. Observations of the MCFs showed that most of the MCC particles had de-fibered into relatively long fibers with a diameter of 3-9 ${\mu}m$, depending on the degree of acid hydrolysis. These results suggest that proper technologies are required to effectively realize the potentials of both NCs and MCFs.

• 임산에너지
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• 제20권2호
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• pp.20-27
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• 2001

글루코스 생산을 위한 효과적인 방법을 개발하기 위해서 cellulase에 의한 현사시 나무의 효소가수분해를 실시하였다. 목재의 효소가수분해는 미생물이 생산한 효소를 사용하여 글루코스를 생산하는 반응이다. 이렇게 얻어진 글루코스는 발효에 의해 쉽게 에탄올로 변환시킬 수 있다. 에탄올은 아세톤이나 부탄올, 시트릭산 그리고 락틴산을 제조하는 원료물질이나 석유자원을 대체할 수 있는 대체에너지 자원이다. 셀룰로오스의 효소가수분해 기작은 endo-cellulase, exo-cellulase 그리고 β-D-glucosidase라는 세 개의 서로 다른 형태의 효소가 연속적인 반웅에 의해 일어난다고 설명되어지고 있다. 본 실험의 목적은 다양한 농도의 수산화나트륨으로 현사시나무를 전처리 하여 이러한 전처리가 셀룰로오스의 결정화도와 리그닌함량에 미치는 영향과 가수분해율과의 관계를 조사하였다.

• 폴리머
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• 제36권3호
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• pp.372-379
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• 2012

본 연구에서는 실리카 나노입자의 표면을 실란 커플링제인 bis[3-(trimethoxysilyl)propyl]amine(BTMA)을 사용하여 개질하였다. BTMA의 가수분해 시간, 농도 및 개질 시간의 변화가 실리카 표면 개질 반응에 미치는 영향을 Fourier transform infrared spectroscopy(FTIR), elemental analysis(EA) 및 고체 상태 cross-polarization magic angle spinning(CP/MAS) nuclear magnetic resonance spectroscopy(NMR)법을 사용하여 분석을 수행하였다. 연구결과 BTMA의 가수분해 시간, 농도 및 표면 개질 시간이 증가할수록 3737 $cm^{-1}$에 나타나는 실리카의 고립 실란올(isolated silanol) 피크의 세기는 점점 약해지고, 도입되는 BTMA의 $-CH_2$ 기에 의한 신축(stretching) 및 굽힘(bending) 진동 피크는 점점 강하게 나타났다. EA 분석을 통한 N 및 C의 함량에서도 같은 경향을 나타내었다. BTMA를 사용한 실리카 입자의 처리 조건 중, BTMA의 농도 변화는 실리카 입자 표면과 반응하는 BTMA의 양에 큰 영향을 미치지만, BTMA의 가수분해 시간 및 표면 개질 반응 시간의 영향은 크지 않은 것으로 나타났다.