• Korean Journal of Food Science and Technology
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• v.21 no.1
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• pp.1-8
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• 1989

Ten cultivars of malting barley grown at four locations were malted and assayed for six enzymes involved in the degradation of nucleic acids. Among these enzymes were deoxyrinonuclease, ribonuclease, phosphodiesterase, 3'- and 5'- nucleotidases and phosphomonesterase. Activities of all enzymes in five-day malts were significantly affected by variety and location of growth. The average levels of ribonuclease, deoxyribonuclease, 3'-nucleotidase and 5'-nucleotidase of 80 five-day malts were 11.2, 5.7, 5.6 and 1.2 units per gram of malt, respectively. Six-rowed barley malts contained higher levels of deoxyribonuclease, phosphodiesterase and 3'-nucleotidase than those of two-rowed barley malts, while two-rowed barley malts contained significantly higher ribonuclease levels than those of six-rowed barley malts.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2005.10a
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• pp.290-293
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• 2005

장내 단백질 가수분해효소에 의한 casein 분해산물들의 ACE 저해 활성을 비교하기 위하여 인공위액, 인공장액 및 인공위액과 장액 연속처리를 각각 반응조건으로 일정시간 casein을 가수분해한 후 각 효소 가수분해물이 혈압상승 peptide 생성효소인 Angiotensin converting enzyme(ACE)에 대한 저해활성을 측정하였다. 각 소화액에 따른 가수분해물은 모두 ACE 저해활성을 나타내었으며, 2시간 효소처리를 하였을 때, 인공위액, 인공장액, 인공위액과 장액 가수분해물은 각각 69%, 80% 및 88%로 최대 ACE 저해활성을 보였다. 그리고 casein의 가수분해 정도를 확인하기 위한 SDS-PAGE에서는 인공위액으로 처리한 군보다 인공장액으로 처리한 군이 더 작은 분자량으로 분해되는 것을 확인할 수 있었고, 인공위액과 장액을 함께 처리한 군에서는 1시간 안에 대부분의 분해가 이루지는 것을 관찰할 수 있었다.

• Korean Journal of Food Science and Technology
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• v.29 no.6
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• pp.1125-1130
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• 1997

The effects of enzyme combination, pH, acid washing and enzyme treatment sequence were investigated in the hydrolysis of soy protein. Comparing Alcalase vs. Neutrase/Alcalase, it appeared that Neutrase/Alcalase was more efficient than Alcalase alone, as the highest degree of hydrolysis (DH) was seen in Neutrase/Alcalase. A surprisingly high DH (more than 60%) was observed with Flavourzyme in the second hydrolysis. The separation of insolubles from the first hydrolysis had little effect on the second hydrolysis. When the washing water from the first hydrolysis was reused in the next hydrolysis, the DH and protein recovery were increased. The addition of calcium ion showed not so much positive effects by the stabilization of Neutrase on the Protein hydrolysis. The use of carbohydrase and repeated acid washing gave positive effects on DH. The simultaneous treatment using endoprotease and exoprotease with pH adjustment improved DH significantly.

• Korean Journal of Food Science and Technology
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• v.50 no.2
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• pp.203-208
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• 2018

In this study, the hydrolysis conditions for the production of anti-inflammatory peptides from meat and roe hydrolysates of sandfish (Arctoscopus japonicus) were determined by measuring the nitric oxide (NO) scavenging enzymatic activity, experimental pH, temperature, enzyme concentration, and hydrolysis time. The optimal conditions determined when using meat hydrolysate were a pH value of 5.0, at a temperature of $30^{\circ}C$, 1% enzyme concentration, and 4 h hydrolysis time. The optimal conditions when using roe hydrolysate were a pH of 5.0, a temperature of $70^{\circ}C$, enzyme concentration of 3%, and hydrolysis time of 3 h. The NO scavenging activities of meat and roe hydrolysate were determined to be 18.94 and 19.81%, respectively. In summary, this study determined the optimum enzymatic hydrolysis conditions for the production of anti-inflammatory peptides from sandfish.

• Microbiology and Biotechnology Letters
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• v.45 no.3
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• pp.265-270
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• 2017

A key virulence factor for urinary tract pathogens is the enzyme urease, which catalyzes the hydrolysis of urea into ammonium ions and carbonic acid. Urease activity plays an important role in the pathogenesis of urinary tract infection. In this study, the inhibitory effect of zerumbone against six urease-producing bacteria (Klebsiella oxytoca, K. pneumoniae, Morganella morganii, Proteus mirabilis, P. vulgaris, and Staphylococcus saprophyticus) and their urease activities were evaluated. The results of the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) tests showed that zerumbone had antibacterial effect against these six urease-producing bacteria. The MIC and MBC of zerumbone ranged from 0.5 to 2 mM and 1 to 4 mM, respectively. In the urease inhibitory assay, zerumbone showed better urease inhibition ($56.28{\pm}2.45-37.83{\pm}3.47%$) than the standard urease inhibitor, acetohydroxamic acid ($40.46{\pm}1.94-22.99{\pm}3.53%$). However, zerumbone did not affect the levels of the urease subunit. These results clearly indicated that zerumbone has antibacterial potential against urease-producing bacteria and possesses excellent bacterial urease inhibition properties.

• Food Science of Animal Resources
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• v.22 no.1
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• pp.87-93
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• 2002

Angiotensiri-I converting enzyme(ACE) catalyst the removal of the C-terminal dipeptide from the angiotensin-I to give the angiotensin-II, a potent peptide that causes constriction of regulation of blood pressure. Recently, ACE inhibitor peptides have been isolated from enzymatic digests of food protein. The aim of this study was to identify bovine casein hydrolysates with ACE inhibitory properties in different enzymatic hydrolysis conditions. The casein were hydrolyzed neutrase, alcalase, protamax, flavourzyme, premed 192, sumizyme MP, sumizyme LP and pescalase alone and with an enzyme combination. Premed 192 produced ACE inhibitory peptides most efficiently. In order to ACE inhibitory peptide produced enzymatic hydrolysis condition were premed 192 added to casein ratio of 1:100(w/w), and incubated at 47$\^{C}$ for 12hrs. Casein hydrolysate gave 50% inhibition(IC$\_$50/ value) of ACE activity at concentration with 248ug/ml(general method) and 265ug/ml(pretreatment method) respectively.

• KSBB Journal
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• v.10 no.5
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• pp.540-546
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• 1995

Dry corn gluten meal of 70% protein content was enzymatically hydrolyzed by alkaline protease in a pH-state reactor. Such process variables as temperature, pH, and enzyme-to-substrate ratio were varied, and at each condition degree of hydrolysis was monitored and calculated. The ultimate degree of hydrolysis, which ranged between 25 and 28% based on gluten protein mass, was not significantly affected by the process variables. However, $50^{\circ}C$ and pH 9-10 appeared optimum. Kinetic analysis indicated enzyme deactivation was negligible during the hydrolysis, and the experimental data were near perfectly fitted to the model kinetic equation which was modified after neglecting enzyme deactivation term. The enzyme reaction was 1$100\times$ scaled up and basically the same hydrolysis performance was resulted. Amino acid analysis showed the hydrolyzate was relatively rich in glutamine/glutamic acid, leucine, and alanine at 19.6, 16.1, and 12.3 mole %, respectively.

• Journal of fish pathology
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• v.27 no.1
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• pp.25-33
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• 2014

Hydrolase activities of excretory-secretory products (ESP) and somatic extracts (SE) from Anisakis simplex sensu stricto (s.s.) and Anisakis pegreffii larvae were investigated by using API ZYM kit. In esterase group, acid phosphatase showed high activity from both of A. simplex (s.s.) and A. pegreffii. Esterase (C4) showed activity only from SE and A. simplex (s.s.) showed higher activity than A. pegreffii. Alkaline phosphatase, acid phosphatase and naphthol-AS-BI-phosphohydrolase showed higher activity in 3rd stage larvae than in 4th stage larvae of both species. In aminopeptidase group, only leucine arylamidase showed remarkable activity in SE of both anisakid species, and A. simplex (s.s.) SE showed higher activity than A. pegreffii SE. In glycosidase group, N-acetyl-${\beta}$-glucosaminidase, ${\alpha}$-mannosidase, ${\alpha}$-fucosidase showed higher activity in A. simplex (s.s.) than A. pegreffii, and 4th larvae showed higher activity than 3rd larvae. These differences in hydrolase activity of anisakid nematodes larvae are thought to be due to different metabolism such as growth, moulting, digestion and feeding.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.2
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• pp.226-233
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• 1993

Enzymatic hydrolysates of food proteins (defatted soybean cake, egg albumin and casein) were tested for inhibitory activity against angiotensin-I converting enzyme (ACE). Food proteins were hydrolysed with complex enzyme, bromelain, alcalase, $\alpha$-chymotrypsin, trypsin, papain and pepsin by heating method. The hydrolysates obtained from the treatment of complex enzyme and bromelain showed the higher ACE inhibitory activity. ACE inhibitory activity of hydrolysates exhibited a tendency to be increased until 8hrs and increased with increment of concentration. The activity was also stable by heat treatment at 10$0^{\circ}C$ for 20min. Molecular weight of active fraction was about 1, 400 and defatted soybean cake hydrolysate below 1, 400 in case of defatted soybean cake hydrolysate treated with alcalase. Amino acid of the active fractions was abundant in Asp, Glu, Lys, lle, Leu, Ala and Val.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.04a
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• pp.145.1-145
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• 2003

대두 단백질을 효소로 가수분해 하였을 때 생성되는 peptide의 항균활성을 조사하고 천연항균제로서 이용 가능성을 검토하기 위하여 분리 대두 단백질에 5종의 단백질 가수분해 효소를 작용시켜 생성된 가수분해물의 항균력을 측정하고 한외여과하여 분자량별로 분리된 각 fraction의 항균활성과 HPLC로 정제하여 항균성 peptide 의 아미노산 결합순서를 분석하여 다음과 같은 결론을 얻었다. 분리대두 단백질에 5종의 단백질 분해효소를 작용시켜 제조한 가수분해물 중 Asp.saitoi protease로 작용시킨 것이 항균활성이 높았다. Asp. saitoi protease로 작용시킨 대두 단백질의 가수분해물을 membrane filter로 여과한 결과 분자량 1000-3000 fraction에서 항균활성이 가장 높았다. 분자량 1000-3000 범위을 가진 가수분해물의 MIC는 0.5-0.8mg/$m\ell$ 이었으며 그람 양성균과 음성균 모두의 증식을 억제하는 경향을 보였다. 분리 대두 단백으로부터 얻어진 항균성 peptide는 121$^{\circ}C$, 10분간 열처리하여도 안정하였으며 한외여과에 의하여 분자량 1000-3000범위의 가수분해물을 동결건조하여 gel filteration하였을 때 2개의 fraction에서 항균 활성을 나타내었다. HPLC결과 RT 16.02 의 peak에서 항균활성이 확인되었고 질량은 1,633이었으며 아미노산 결합순서는 H$_2$N-G-P-P-G-V-V-A-T-V-V-A-A-R-COOH 이었다.