• Proceedings of the Korean Society of Fisheries Technology Conference
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• 1998.06a
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• pp.175.2-176
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• 1998

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2005.10a
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• pp.168-171
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• 2005

한우의 Myosin B 단백질을 단백질 가수분해 효소인 pepsin으로 처리한 다음 단백질의 함량과 혈압상승 펩티드 생성효소인 angiotensin-I converting enzyme(ACE)에 대한 저해활성을 측정하였다. 등심이 우둔에 비해 단백질의 함량이 높았으며, 가수분해 처리 후 우둔과 다르게 등심은 3시간 가수분해 처리구에서 단백질의 함량이 높게 나타났다. ACE 저해활성은 등심에서는 3시간, 우둔에서는 6시간동안 가수분해시켰을 때 ACE 저해율이 유의적으로 가장 높게 나타났으며, 3, 6시간동안 가수분해시켰을 경우 부위 별로 유의적인 차가 있었으나(p<0.05), 0, 1시간동안 가수분해 시켰을 때는 부위간의 유의적인 차는 없었다(p>0.05). ACE 저해율이 가장 좋은 가수분해 처리구를 ultrafiltration시킨 결과, 저분자 peptide 상태의 가수분해물이 고분자에 비하여 ACE 저해율이 높은 것으로 나타났다. 차후 ACE 억제활성도가 높은 단백질을 분리하여 가장 우수한 분획을 찾아 아미노산 염기서열을 밝혀 고혈압 억제제로 합성 개발하는 연구를 추진할 예정이다.

• 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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.4
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• pp.587-594
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• 2010

To develop commercially available food protein hydrolysates, the effects of different types of enzymes and substrates on bitterness and solubility of partially hydrolyzed food proteins were investigated. Four types of proteins (casein, isolated soy protein (ISP), wheat gluten, and gelatin) and five types of proteolytic enzymes (a microbial alkaline protease (alcalase), a microbial neutral protease (neutrase), papain, bromelain, trypsin) were used. To profile the pattern of hydrolysis, the degree of hydrolysis (DH) were monitored during 180 min of reaction time by pH-stat method. Casein showed the highest susceptibility to hydrolysis for all five proteases compared to those of ISP, gluten, and gelatin. In addition, the bitter intensity and solubility (nitrogen soluble index, NSI) of each protein hydrolysate were compared at DH 10%. Bitterness and solubility of protein hydrolysates were highly affected by DH and the types of enzymes and substrates. At DH=10%, casein hydrolysate by trypsin, ISP and gluten hydrolysates by either bromelain or neutrase, and gelatin hydrolysates by the five proteases tested in this study were highly soluble and less bitter.

• 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 Membrane Society of Korea Conference
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• 1993.10a
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• pp.42-43
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• 1993

최근 특별한 기능을 갖는 단백질의 수요가 늘어남에 따라 단백질의 기능성을 개량하려는 연구가 활발히 이루어지고 있다. 이들 중 대표적인 것이 단백질을 단백질 분해효소로 처리한 가수분해물을 환자의 영양강화제와 같은 의약품이나 기능성이 요구되는 식량소재로서의 이용이다. 단백질의 효소적 가수분해에 있어서 회분식 공정은 장치가 간단하고 조작이 단순하며, 고 농도의 기질을 사용할 수 있지만 많은 양의 효소가 필요하며 높은 에너지와 노동력이 요구된다. 그리고 최종생성물의 저해작용으로 인해 수율이 적고 최종생성물의 기능적인 성질을 조절할 수 없는 단점이 있다.

• 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.

• Applied Biological Chemistry
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• v.38 no.6
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• pp.563-569
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• 1995

Effect of protease and 2-mercaptoethanol treatment on the texture of cooked rice was investigated. Hardness, chewiness and gumminess of cooked rice were decreased by reducing the disulfide bonds of protein using 2-mercaptoethanol. Protease-treated rice grains, when cooked, showed more favorable results in stickiness measured by Instron, hardness measured by rheometer and sensory acceptability of cooked rice. Water content and volume expansion of cooked rice were increased by protease or 2-mercaptoethanol treatment. This results suggested that the textural characteristics of cooked rice may be influenced by surrounding or closely associated protein.

• Korean Journal of Microbiology
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• v.27 no.3
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• pp.237-244
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• 1989

A soluble intracellular protease from cells of Pseudomonas carboxydovorans, a carboxydobacterium, grown on nutrient broth was purified 68-fold in five steps to better than 95% homogeneity with a yield of 2.4% using azocasein as a substrate. The enzyme activity was not detected from cells grown on pyruvate, succinate, acetate, or CO as a sole source of carbon and energy. The molecular weight of the native enzyme was determined to be 53,000. Sodium dodecyl sulfate-gel electrophoresis revealed the purified enzyme a monomer. The enzyme was found to be a serine-type protease. The enzyme activity was inhibited completely by several divalent cations such as $Cd^{2+}, Cu^{2+}, Hg^{2+}$, and $Fe^{2+}$. The enzyme was also inhibited by EGTA, but was stimulated by iodoacetamide. The optimal pH and temperature for the enzyme reaction were found to be 8.0 and $50^{\circ}C$, respectively. The enzyme was inactive on CO dehydrogenase.

• Korean Journal of Food Science and Technology
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• v.16 no.2
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• pp.228-234
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• 1984

A partial hydrolysis of soybean protein isolate was carried out by using pepsin and trypsin. The degree of hydrolysis was evaluated by chemical analysis, viscometric measurements and gel electrophoresis. The functional properties of the hydrolyzates such as flow behavior, emulsion properties and foaming properties were evaluated. A selective hydrolysis of 11S protein fraction by pepsin was observed from the SDS-PAG electrophoresis. The changes in the molecular weight distribution by different conditions of enzyme hydrolysis were evaluated. The changes in the intrinsic viscosity of the protein hydrolylate by reaction time were highly correlated to the contents of TCA soluble protein and 0.03 M $CaCl_2$ soluble nitrogen. The degree of hydrolysis ($DH_{TCA}$, $DH_{Ca}$) were used to evaluate the effect of enzyme treatment on the functional properties of the hydrolyzate. The apparent viscosity and emulsion capacity and stability of the protein solution decreased as DH increased, while the foaming capacity increased linearly with the increasing DH.