• Journal of Life Science
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• v.20 no.11
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• pp.1656-1661
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• 2010

Alkaline protease for the hydrolysis of egg yolk protein was immobilized on five carriers - Duolite A568, Celite R640, Dowex-1, Dowex 50W and Silica gel R60. Duolite A568 showed a maximum immobilization yield of 24.7%. Optimum pH for the free and immobilized enzyme was pH 8 and 9, respectively. However, no change was observed in optimum temperature ($50^{\circ}C$). Thermal stability was observed in immobilized enzymes compared to free enzymes. The immobilized enzyme retained 86% activity after 10 cycle operations in a repeated batch process. The effect of flow rate on the stability of enzyme activity in continuous packed-bed reactor was investigated. Lowering flow rate increased the stability of the immobilized enzyme. After 96 hr of continuous operation in a packed-bed reactor, the immobilized enzyme retained 83 and 61% activity when casein and egg yolk were used as a raw materials, respectively.

• Journal of the Korean Applied Science and Technology
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• v.33 no.2
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• pp.293-303
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• 2016

Protein hydrolysate that shows physiological function such as antioxidant, suppression of hypertension, immunodulatory, alleviation of pain, and antimicrobial activity has been known as playing important role like hormone. This study was performed to optimize the hydrolysis of the wing's meat of Yosan-Ogae by a commercial protease. The ranges of processes were the reaction temperature of 40 to $60^{\circ}C$, pH 6 to 8, and enzyme concentration 1 to 3%(w/v). As a result, the optimization of process was determined at temperature of $48-50^{\circ}C$, pH of 7.0-7.2, and enzyme concentration of 3%(w/v), and degree of hydrolysis was 68 to 69% at above conditions. The molecular weight of hydrolysate was distributed to 500-1,200 Da and showed typical peptides. The amino acids of peptides showing presumably antioxidant activity such as histidine, proline, methionine, cystein, tyrosine, tryptophan, phenylalanine comprised about 43.07%. The glutamic acid was 13.6%. Therefore, we expect that those products are useful as functional food ingredients.

• Korean Journal of Food Science and Technology
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• v.43 no.6
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• pp.729-734
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• 2011

With the goal of transforming rice protein from an insoluble to a soluble form to increase the industrial utilization of rice wine meal (RWM), RWM was derivatized using commercial proteases and the RWM hydrolysates were characterized. Eight commercial proteases were used individually or in combination for hydrolysis of RWM. The degree of hydrolysis was assessed by determining the soluble protein in supernatant using the Lowry assay, protein in precipitates using a semimicro Kjeldahl procedure, and gravimetrically by the weight difference before and after hydrolysis. Protamex, Alcalase and Protease N proteases were most effective for hydrolysis of RWM. Although these assessment methodologies displayed some variation, they generally showed a similar pattern. When the aforementioned three proteases were simultaneously used to treat RWM, no significant difference was observed between the three assays (p<0.05) indicating an absence of enzymatic synergy.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.23 no.2
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• pp.33-47
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• 1997

단백질 또는 peptide bond를 가수분해하는 protease는 현재 산업의 각 분야에서 널리 응용되고 있으며, 사용범위가 점차 확산되고 있는 추세이다. 따라서 본 실험에서는 미생물이 생산하는 단백질분해효소를 분리 정제하여 그의 성질을 규명 및 skin turn-over 효과를 조사하였다.

• Korean Journal of Microbiology
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• v.51 no.3
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• pp.187-193
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• 2015

Candida (also known as Pseudozyma) antarctica lipase B (CAL-B) has been intensely studied in academic and industrial fields. However, the research related to its homologous enzymes has been rarely reported. In the current investigation, protein sequence similarity search of CAL-B has been conducted and six homologous protein sequences were identified. After the syntheses of their codon-optimized genes, the synthetic genes have been cloned into a periplasmic expression vector to express in Escherichia coli. Among six homologous sequences, four sequences were successfully expressed in E. coli. The hydrolytic activities of the expressed proteins towards 4-nitrophenyl acetate and 4-nitrophenyl butyrate were measured and compared with those of CAL-B to identify whether the expressed proteins work as a hydrolase. It has been revealed that the expressed proteins can hydrolyze the substrates and the specific activities were determined as $(1.3-30){\times}10^{-2}{\mu}mol/min/mg$, which are lower than those of CAL-B. Among these homologous enzymes, Pseudozyma hubeiensis SY62 exhibits the comparable enantioselectivity to that of CAL-B towards the hydrolysis of (${\pm}$)-1-phenylethyl acetate.

• Korean Journal of Food Science and Technology
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• v.20 no.3
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• pp.344-349
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• 1988

Proteolysis of 7S and 11S soy protein-rich fraction(PRF) with commercial proteases(alcalase and pronase) apperently increased protein solubility at pH 5, heat coagulation and calcium tolerence, while decreasing emulsifying capacity and foam stability regardless of the kind of protein and protease used. However, the proteolysis decreased the protein solubility of 7S PRF at pH 6 and 11S PRF at pH 4. The proteolysis of 11S PRF increased oil absorption and foam expansion, while slight decrease or almost no change was noted on 7S PRF. Heat stabilities of the emulsion and kinetic viscosities changed very little by the proteolysis.

• Korean Journal of Food Science and Technology
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• v.53 no.6
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• pp.695-700
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• 2021

The purpose of this study was to prepare low-molecular weight collagen using a commercial proteolytic enzyme (Protamex) from collagen extracted from feet of Korean native chicken and to investigate the quality characteristics of this collagen. The collagen content of Korean native chicken feet was 13.9 g/100 g, which was higher than the 6.21 g/100 g of general broilers. It was found that the content of low molecular weight collagen increased as the concentration of proteolytic enzymes and reaction time increased. In particular, reaction with 1% Protamex for 7 h resulted in 55.6% of low molecular weight (1,000-5,000 Da) collagen content, and the average molecular weight was 5,390 Da. Regarding the texture of the enzyme-treated collagen, the collagen with high molecular weight peptides decomposed into low molecular weight peptides, and the gel type could not be formed, whereas the sol type was maintained.

• 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.

• Korean Journal of Food Science and Technology
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• v.34 no.2
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• pp.269-273
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• 2002

The amlyolytic enzymes $({\alpha}-amlyase,\;{\beta}-amlyase,\;glucoamlyase)$ and protease activities were studied during Kimchi fermentation. The optimum pH of Kimchi was 4.1 within 2 days at $20^{\circ}C$. The optimum acidity calculated as lactic acid was 0.44% within 2 days at $20^{\circ}C$. On the first day of fermentation, ${\alpha}-amlyase$ activity was reduced from 0.49 unit/mg protein to 0.20 unit/mg protein but increased in the later stage of fermentation. In case of ${\beta}-amlyase,\;glucoamlyase$ and protease showed the highest activity of 505.73, 13.43 and 1.72 unit/mg protein at the 2nd day of fermentation at $20^{\circ}C$. In the sensory evaluation of Kimchi were estimated taste, color, texture and overall acceptability. Overall acceptability of kimchi showed the highest score value on the 2nd day of fermentation, respectively.

• Journal of Animal Environmental Science
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• v.10 no.2
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• pp.119-126
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• 2004

The protein in the extracts from the skins of pineapple and kiwi and the optimal conditions to hydrolyze blood, egg and gluten meals with them were investigated. Protein analysis by SDS-polyacylamide gel electrophoresis showed one protein band with 22 kd molecular weight in the pineapple skin extract, and Hve protein bands with 27 kd, 22.5 kd, 22 kd, 19 kd, and 14.4 kd molecular weight in the kiwi skin extract. The 22 kd protein in the pineapple skin extract is assumed to be bromelain, and the 27 kd protein in the kiwi skin extract is assumed to be actinidin, both are pretense. The optimal conditions for hydrolysis of blood, egg, and gluten meals we: 6-24 hours in time, $60^{\circ}C$ in temperature, and pH 4-pH 7.