• 한국수산과학회지
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• 제30권5호
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• pp.842-849
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• 1997

Pepsin, trypsin, $\alpha-chymotrypsin$, papain, bromelain, 복합효소, Novozym 89, Neutrase 0.51., Protamex 및 Alcalase 0.6L 등으로 가수분해하여 얻은 멸치육 단백질 효소 가수분해물의 항산화작용을 살펴본 결과, 항산화작용이 매우 우수한 것으로 나타났으며 특히 생체내 소화효소의 하나인 pepsin과 식품가공용 단백분해효소인 Protamex에 의한 가수분해물의 항산화작용이 우수한 것으로 나타났다. 이들의 다른 항산화제와의 상승작용에 있어서는 $\alpha-tocopherol$과는 상승작용이 있는 것으로 나타났으나 BHT에 대해서는 BHT 자체의 강한 항산화능으로 상승작용을 확인할 수 없었다. 금속이온 $(Fe^{3+},\;Cu^{2+})$에 대한 봉쇄작용 또한 우수한 것으로 나타났으며, 특히 pepsin, $\alpha-chymotrypsin$ 및 papain유래 가수분해물이 $Cu^{2+}$이온에 대하여 높은 억제작용을 나타내었다. Pepsin유래 멸치육 단백질 효소가수분해물을 이온교환크로마토그래피 및 겔 크로마토그래피에 의하여 분획하고 얻어진 획분별 항산화작용은 P-2 (fraction No. $26\~31$)획분에서 가장 큰 것으로 나타났다. 이 때 가수분해전후 및 활성획분의 아미노산조성은 aspartic acid와 glutamic acid가 증가한 반면 alanine, cysteine, tyrosine 및 phenylalanine은 감소한 것으로 나타났다.

• International Journal of Industrial Entomology and Biomaterials
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• 제2권1호
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• pp.7-13
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• 2001

Enzymatic hydrolysis of different forms of silk fibroin (soluble, gel and insoluble forms) by industrial and commercial enzyme preparations to obtain aqueous and powdered silk fibroin in relatively mild conditions was investigated. A mono-enzymatic hydrolysate systems were tested for hydrolysis of water-soluble form of fibroin as most productive form of protein substrate. Insoluble forms of substrate usually were hydrolyzed less effective. In some cases from soluble fibroin substrate gel was formed during hydrolysis process. This hindered intermixing and decreased rates of hydrolysis. Insoluble sediments were formed in enzymatic hydrolysates in other cases. These sediments and also sediment after chemical hydrolysis were purified and tested on amino acids content for comparison. Sediments formation in these conditions are considered as pure tyrosine isolation method. Obtained hydrolysates were characterized by gel-chromatography analysis and other standard biochemical methods. Possibility of application of enzymatic hydrolysis for preparation of silk fibroin hydrolysates is discussed.

• Asian-Australasian Journal of Animal Sciences
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• 제16권3호
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• pp.417-424
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• 2003

Inhibitory activities against angiotensin I-converting enzyme (ACE) of enzymatic hydrolysates of porcine skeletal muscle proteins were investigated. Myosin B, myosin, actin, tropomyosin, troponin and water-soluble proteins extracted from pork loin were digested by eight kinds of proteases, including pepsin, $\alpha$-chymotrypsin, and trypsin. After digestion, hydrolysates produced from all proteins showed ACE inhibitory activities, and the peptic hydrolysate showed the strongest activity. In the case of myosin B, the molar concentration of peptic hydrolysate required to inhibit 50% of the activity increased gradually as digestion proceeded. The hydrolysates produced by sequential digestion with pepsin and $\alpha$-chymotrypsin, pepsin and trypsin or pepsin and pancreatin showed weaker activities than those by pepsin alone, suggesting that ACE inhibitory peptides from peptic digestion might lose their active sequences after digestion by the second protease. However, the hydrolysates produced by sequential digestion showed stronger activities than those by $\alpha$-chymotrypsin, trypsin or pancreatin alone. These results suggested that the hydrolysates of porcine meat were able to show ACE inhibitory activity, even if they were digested in vivo, and that pork might be a useful source of physiologically functional factors.

• 한국축산식품학회지
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• 제34권3호
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• pp.362-371
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• 2014

This study utilized commercially available proteolytic enzymes to prepare egg-white protein hydrolysates (EPHs) with different degrees of hydrolysis. The antioxidant effect and functionalities of the resultant products were then investigated. Treatment with Neutrase yielded the most ${\alpha}$-amino groups (6.52 mg/mL). Alcalase, Flavourzyme, Protamex, and Ficin showed similar degrees of ${\alpha}$-amino group liberation (3.19-3.62 mg/mL). Neutrase treatment also resulted in the highest degree of hydrolysis (23.4%). Alcalase and Ficin treatment resulted in similar degrees of hydrolysis. All hydrolysates, except for the Flavourzyme hydrolysate, had greater radical scavenging activity than the control. The Neutrase hydrolysate showed the highest 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity ($IC_{50}=3.6mg/mL$). Therefore, Neutrase was identified as the optimal enzyme for hydrolyzing egg-white protein to yield antioxidant peptides. During Neutrase hydrolysis, the reaction rate was rapid over the first 4 h, and then subsequently declined. The $IC_{50}$ value was lowest after the first hour (2.99 mg/mL). The emulsifying activity index (EAI) of EPH treated with Neutrase decreased, as the pH decreased. The EPH foaming capacity was maximal at pH 3.6, and decreased at an alkaline pH. Digestion resulted in significantly higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ABTS radical scavenging activity. The active peptides released from egg-white protein showed antioxidative activities on ABTS and DHHP radical. Thus, this approach may be useful for the preparation of potent antioxidant products.

• Journal of Dairy Science and Biotechnology
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• 제35권4호
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• pp.249-254
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• 2017

The purpose of this study was to investigate the acid tolerance, bile acid tolerance, and fermentation activity of lactic acid bacteria isolated from Kimchi in the presence of hydrolysates of whey protein concentrate. Kimchi isolates DK109, DK119, DK121, DK128, DK211, DK212, and DK215, which were identified as Lactobacillus sp., and L. casei DK128 showed the highest acid and bile acid tolerance. To produce whey hydrolysates, enzymes were added to a 10% (w/v) whey protein concentrate (WPC) solution at 1:50 (w/v, protein). The viabilities of the DK strains were determined in the presence of low pH and bile salts. Then, yogurt was produced via fermentation with L. casei DK128, an isolate from Kimchi, in the presence of the following additives: CPP, WPC, and WPC hydrolysates (WPCH) generated by alcalase (A) or neutrase (N). The produced yogurts were subjected to various analyses, including viable cell counts (CFU/mL), pH, titratable activity, and sensory testing. After 8 h of fermentation, the pH and titratable activity values of all test samples were 4.2 and 0.9, respectively. The viable counts of LAB were $3.49{\times}10^8$, $5.72{\times}10^8$, $7.01{\times}10^8$, and $6.97{\times}10^8$, for the Control, CPP, A, and N samples, respectively. These results suggest that whey proteins have potential as dietary supplements in functional foods and that WPCH could be used in yogurt as a low-cost alternative to CPP.

• 한국유가공학회:학술대회논문집
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• 한국유가공기술과학회 1997년도 춘계 제44회 유가공 심포지움
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• pp.35-40
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• 1997

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 2003년도 2003 Annual Meeting, BioExhibition and International Symposium
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• pp.195-195
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• 2003

• 한국축산식품학회:학술대회논문집
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• 한국축산식품학회 2005년도 정기총회 및 제35차 춘계 학술 발표대회
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• pp.109-116
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• 2005

• 한국축산식품학회지
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• 제43권1호
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• pp.46-60
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• 2023

Slaughterhouse blood is a by-product of animal slaughter that can be a good source of animal protein. This research purposed to examine the functional qualities of the blood plasma from Hanwoo cattle, black goat, and their hydrolysates. Part of the plasma was hydrolyzed with proteolytic enzymes (Bacillus protease, papain, thermolysin, elastase, and α-chymotrypsin) to yield bioactive peptides under optimum conditions. The levels of hydrolysates were evaluated by 15% sodium dodecyl sulfate polyacrylamide gel electrophoresis. The antioxidant, metal-chelating, and angiotensin I-converting enzyme (ACE) inhibitory properties of intact blood plasma and selected hydrolysates were investigated. Accordingly, two plasma hydrolysates by protease (pH 6.5/55℃/3 h) and thermolysin (pH 7.5/37℃/3-6 h) were selected for analysis of their functional properties. In the oil model system, only goat blood plasma had lower levels of thiobarbituric acid reactive substances than the control. The diphenyl picrylhydrazyl radical scavenging activity was higher in cattle and goat plasma than in proteolytic hydrolysates. Ironchelating activities increased after proteolytic degradation except for protease-treated cattle blood. Copper-chelating activity was excellent in all test samples except for the original bovine plasma. As for ACE inhibition, only non-hydrolyzed goat plasma and its hydrolysates by thermolysin showed ACE inhibitory activity (9.86±5.03% and 21.77±3.74%). In conclusion, goat plasma without hydrolyzation and its hydrolysates can be a good source of bioactive compounds with functional characteristics, whereas cattle plasma has a relatively low value. Further studies on the molecular structure of these compounds are needed with more suitable enzyme combinations.

• 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.