• 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.

• 한국식품과학회지
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• 제24권3호
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• pp.294-299
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• 1992

본 연구에서는 분리대두단백질에 단백질 가수분해효소를 처리하여 대두단백질에 가수분해적 변성을 야기하여 그 기능성을 변화 고찰하고 실제 식품에의 이용방법으로 효소처리된 두유로 두부를 만들어 물성실험과 관능평가를 실시하였다. 장엽에서 SPI를 제조한 후 15분간 bromelain으로 처리하여 2.7% 가수분해된 MSPI를 만들어 기능특성을 측정 비교하였다. MSPI는 전 pH범위에서 용해도가 증가하였고, 특히 등전점에서 15% 정도 증가하였다. 유화형성력과 기포팽창력은 증가하였으나 이들의 안정성은 감소하였는데, 특히 기포안정성은 알칼리쪽에서 급격히 감소하였고, 등전점에서는 가장 큰 것으로 나타났다. 표준두유와 변형두유를 혼합하여 제조한 두부로 물성실험과 관능평가를 실시하였을 때 압착실험에서는 변형두부I이 연하고 탄력성 있는 두부를 형성하는 것으로 나타났다. 각 두부의 물성모형은 spring 한개와 Maxwell 모형 세개를 가진 7요소모형으로 동일한 물성모형을 나타내었다. 관능평가에서는 표준두유와 변형두유를 3 : 1의 비율로 혼합하여 제조한 두부의 품질이 가장 우수한 것으로 평가되었다.

• Journal of Microbiology
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• 제44권5호
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• pp.508-514
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• 2006

In this study, the double-stranded DNA-dependent activities of Deinococcus radiodurans RecA protein (Dr RecA) were characterized. The interactions of the Dr RecA protein with double-stranded DNA were determined, especially dsDNA-dependent ATP hydrolysis by the Dr RecA protein and the DNA strand exchange reaction, in which multiple branch points exist on a single RecA protein-DNA complex. A nucleotide cofactor (ATP or dATP ) was required for the Dr RecA protein binding to duplex DNA. In the presence of dATP, the nucleation step in the binding process occurred more rapidly than in the presence of ATP. Salts inhibited the binding of the Dr RecA protein to double-stranded DNA. Double-stranded DNA-dependent ATPase activities showed a different sensitivity to anion species. Glutamate had only a minimal effect on the double-stranded DNA-dependent ATPase activities, up to a concentration of 0.7 M. In the competition experiment for Dr RecA protein binding, the Dr RecA protein manifested a higher affinity to double-stranded DNA than was observed for single-stranded DNA.

• 상하수도학회지
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• 제24권5호
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• pp.561-572
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• 2010

The efficiency of biological hydrolysis at $80^{\circ}C$ on municipal solid waste mixed with anaerobic digestion sludge was investigated in 100L batch reactors. The hydrolysis effect was observed within a day, when the hydrolysis reactor used for a pre-treatment reactor for methanogenesis, and the effect was observed during two days, When the reactor used for post-treatment reactor. For both configurations, methane production rate decreased, when hydrolysis was carried out more than a day. Gaseous ammonia in the hydrolysis reactors was successtully removed by the ammonia stripping system. Microbial diversity analysis on the hydrolysis reactors indicated dependency of microbial diversity on the configuration of the hydrolysis reactors. Carbohydrate and lactate degrading microbes dominated in the hydrolysis reactor, when the hydrolysis reactor used for a pre-treatment reactor for methanogenesis, while protein degrading microbes dominated in the post-treatment reactor.

• Applied Biological Chemistry
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• 제35권6호
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• pp.501-506
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• 1992

두유박 단백질을 시료로 하여 pepsin을 사용한 가수분해와 plastein 합성의 최적조건을 조사하였다. 가수분해의 최적 기질농도는 3%이었으며, 기질에 대한 최적의 효소 농도는 2%이었고, 최적 pH, 반응온도 및 반응시간은 각각 pH 1.7, $45^{\circ}C$ 및 24시간이었다. Plastein 합성 조건으로 기질농도 40%, pH 4.0, 반응온도 $45^{\circ}C$, 반응시간 18시간, (효소/기질) 농도 1%를 설정하였다. 생성된 plastein은 반응시간 및 기질농도 별로 전기영동으로 확인하였다.

• 한국식품저장유통학회지
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• 제30권3호
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• pp.434-445
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• 2023

Hemp (Cannabis sativa L.) seeds have recently been attracting attention as a new high-value-added food material owing to their excellent nutritional properties, and research on the development of functional food materials using hemp seeds is actively progressing. This study aimed to evaluate the antioxidant properties of hemp seed protein hydrolysates. Protein hydrolysates were prepared from defatted hemp seed powder (HS) by enzymatic hydrolysis using five different proteases (alcalase, bromelain, flavourzyme, neutrase, and papain). 2,4,6-trinitrobenzene sulfonic acid (TNBS) assay and SDS-PAGE analysis revealed that HS showed a high degree of hydrolysis after treatment with each enzyme except papain. The total polyphenol content of the protein hydrolysates (<3 kDa) and the RC50 values obtained from two different antioxidant tests showed that alcalase hydrolysate (HSA) had a relatively high level of antioxidant capacity. In addition, treatment with HSA (25-100 ㎍/mL) significantly inhibited linoleic acid peroxidation. These results suggest that hemp seed protein hydrolysates are potential sources of natural antioxidants. Future studies will focus on the identification of active peptides from HSA.

• Preventive Nutrition and Food Science
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• 제15권4호
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• pp.282-286
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• 2010

To isolate a calcium-binding peptide from chlorella protein hydrolysates, chlorella protein was extracted and hydrolyzed using Flavourzyme, a commercial protease. The degree of hydrolysis and calcium-binding capacity were determined using trinitrobenzenesulfonic acid and orthophenanthroline methods, respectively. The enzymatic hydrolysis of chlorella protein for 6 hr was sufficient for the preparation of chlorella protein hydrolysates. The hydrolysates of chlorella protein were then ultra-filtered under 5 kDa as molecular weight. The membrane-filtered solution was fractionated using ion exchange, reverse phase, normal phase chromatography, and fast protein liquid chromatography to identify a calcium-binding peptide. The purified calcium-binding peptide had a calcium binding activity of 0.166 mM and was determined to be 700.48 Da as molecular weight, and partially identified as a peptide containing Asn-Ser-Gly-Cys based on liquid chromatography/electrospray ionization tandem mass spectrum.

• 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.

• Fisheries and Aquatic Sciences
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• 제5권1호
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• pp.21-27
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• 2002

Angiotensin I converting enzyme inhibitory activities of shelled krill (Euphausia superba) hydrolysates by autolysis and by hydrolysis with commercial proteases were analyzed. Among the proteases, Alcalase was the most effective protease for the hydrolysis of krill considering the degree of hydrolysis $(87.5\%)$ and the ACE inhibitory activity $(60\%)$. Four hour hydrolysis suggested as the most suitable and economic. In order to establish the optimum hydrolysis condition of krill, degree of hydrolysis and ACE inhibitory activity as affected by Alcalase concentration and water amount added were statistically analyzed by response surface methodology (RSM). The optimum hydrolysis condition was $2.0\%$ Alcalase hydrolysis in 2 volumes (v/w) of water at $55\% for 4 hr. The hydrolysate prepared from the optimum hydrolysis condition was fractionated by molecular weight. The lower molecular weight fraction showed the higher ACE inhibitory activity. $IC_{50}$ of the fraction under 500 Da was 0.57mg protein/mL.

• Archives of Pharmacal Research
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• 제19권4호
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• pp.326-334
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• 1996

We investigated the optimum conditions for conversion of water-insoluble components of basidiocarps of Ganoderma lucidum to water-soluble components by hydrolyzing with chitinase. We also tried it with Ganoderma luciclum residue remaining after extracting hot water-soluble components of Ganoderma lucidum. After hydrolyzing under optimum conditions (20 ppm chitinase, 2% Ganoderma lucidum or 6% Ganoderma lucidum residue, at pH 3 and at $ 35^{\circ}C$), the contents of total water-soluble components (polysaccharide or protein) were measured, and it was found that the contents of water-soluble components increased to 1.5-2.7 fold. Michaelis constant, $K_m$ and maximum rate, $V_max$ calculated by Lineweaver-Burk plot for hydrolysis of Ganoderma lucidum were 1.75% and 0.02%/min respectively and those for hydrolysis of Ganoderma lucidum residue were 53.15% and 0.53%/min respectively The protein-bound polysaccharide was isolated after hydrolysis and molecular weights were measured by Sepharose CL-4B gel filtration and compared with the molecular weights of polysaccharide before hydrolysis.