• Proceedings of the Korean Society of Life Science Conference
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• 2001.06a
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• pp.3-41
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• 2001

단백질의 부분 가수분해는 산성 음료에서의 용해도 증가, 환자들의 소화력과 알러지 내성의 개선, 다른 기능적 특성의 개발 등을 위하여 식품산업에 널리 이용되고 있다. 그러나 우유 단백질이나 대두 단백질과 같은 몇 가지 단백질들은 가수분해에 의하여 강한 쓴맛을 형성한다, 단백질 가수분해물의 쓴맛에 관한 연구는 1950년대 초에 시작되었으며, 여러 가지 원료로부터 쓴맛물질이 분리되었다. 이들 단백질 가수분해물의 쓴맛 물질은 올리고펩타이드로 알려져 있으며, 펩타이드 분자를 구성하는 소수성 아미노산의 존재와 밀접한 관계가 있는 것으로 보고되고 있다. 본 연구에서는 최근에 발달된 분석기술과 생명공학적 기법으로 E. coli에서 생산한 콩 단백질 단일 subunit를 이용하여 효소적 가수분해물의 분자구조를 확인하고자 하였다. 탈지대두박으로부터 115 glycinin와 E.coli떼서 발현된 proglycinin을 각각 90%, 97%의 정제도로 분리하여 이들 단백질을 trypsin으로 각각 가수분해하였다. 115 glycinin은 효소/기질 비 3%에서 4시간 가수분해에 의해 $14.0{\times}10^{-5}$ M quinine-HCI equivalent의 강한 쓴맛을 나타내었으며, 12%의 가수분해도(DH)를 나타내었다. 대두 단백질의 쓴맛 성분을 확인 위하여 이미 아미노산 서열이 밝혀진 11S glycinin과 proglycinin 가수분해물에서 GP-HPLC, $C_{18}$ RP-HPLC 등을 통하여 쓴맛 peptide들을 분리하였다. 각각의 분획은 다시 21개의 peptide로 분리되어 그 서열이 결정되었으며 이중 RP와 GI는 이미 알려진 쓴맛 dipeptide였고, LAGNQEQE, SAEFG, NALPE, KLHENIAR, GMIYPG 등이 주된 쓴맛 Peptide로 확인되었다. 이들은 11S glycinin의 5개의 subunit 중에서 그 위치가 확인되었다. Proglycinin 가수분해물에서도 11S glycinin과 같은 방법으로 7개의 쓴맛 peptide가 분리되었다. 이들은 $A_{1a}B_{1b}$의 아미노산 서열 중에서 37-42, 103-110, 164-167, 323-327, 367-373의 위치에 분포하고 있었으며, NALKPD, IYPGCPST, SlDT, HNIGQT, NAMFVPH의 서열을 나타내었다. 분리된 쓴맛 peptide 중에서 가장 쓴 두 분회의 peptide를 합성하여 관능 검사한 결과, NALPE는 매우 쓴맛을 내는 peptide로 확인되었다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.4
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• pp.608-616
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• 1996

To propose the use of skipjack processing by-product(SPB) as a food material, the optimal condition for the production of the SPB hydrolysate through enzyme treatment was obtained using RSM(Response Surface Methodology). Among eight pretenses test, Pretense $P^{TM}$ was screened primarily on the aspect of production cost and taste of the product. The extent of autolysis accompanied by endogenous enzyme in the SPB was almost negligible as compared with that of Protense $P^{TM}$ treatment. The derived model equation was within the satisfiable range as indicated by coefficient of $determination(R^2=0.9460)$ and lack of fit(p>0.1) values. From the results of RSM and ridge analysis, the conditions favoring the higllest degree of hydrolysis were: PH 7.2, $51^{\circ}C,$ reaction time of 3.94 hr, substrate concentration of 33.3%, and enzym $e_strate ratio of 0.48%.48%.8%.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.6
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• pp.803-806
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• 1993

The properties of proteolytic enzymes from the fruit of Broussonetia Kazinoki Siebold were investigated. The protease activity of the enzymes from the fruit of Broussonetia Kazinoki Siebold was 1.6 unit. The optimum temperature and pH of the enzymes were $60^{\circ}C$ and 7.0, respectively. The enzymes were stable at pH values from 6 to 8 for 1 hr. at $37^{\circ}C$ of incubation and also retained all activity after incubation for 1 hr. at $60^{\circ}C$. The enzyme preparations showed strong activities toward hemoglobin and collagen.

• Food Science and Preservation
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• v.10 no.1
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• pp.80-88
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• 2003

In order to establish the enzymatic hydrolysis system improving of taste and flavor in the preparation of soy protein hydrolysates using the enzymes with excellent hydrolytic ability and different hydrolysis pattern of soy protein, Degree of hydrolysis(DH) and surface hydrophobicity under the optimal conditions of enzyme reaction, hydrolysis patterns by the SDS electrophoresis and sensory evaluation of soy protein hydrolysates by enzyme reactions were investigated. Four enzyme reactions were highly activated at pH 7.0, 45$^{\circ}C$ under the optimal conditions. As result of changes on the pattern of soy-protein hydrolysates by SDS-electrophoresis, high molecular peptides of hydrolysates by No. 5(Mucor circinelloides M5) and No. 16(Bacillus megaterium B16) enzymes were slowly decrease and 66KD band of these were remained after 3hours reaction. Production of low molecular peptides of hydrolysates by No. 4(Aspergillus oryzae M4) and No. 95(Bacillus subtilis YG 95) enzymes were remarkably detected during the proceeding reactions. As results of HPLC analysis, low molecular peptides of 15∼70KD were mainly appeared during the proceeding enzyme reactions. And, the more DH was increased, the more SDS-surface hydrophobicity was decreased. Hydrolysates by No. 4 enzyme was not only the highest DH of all hydrolysates, but the strongest bitter taste in a sensory evaluation. Sweat taste among the hydrolysates showed little difference. But, when combinative enzymes were treated, combinative enzyme of No. 4(Aspergillus oryzae M4)and No. 16(Bacillus megaterium B16) showed the strongest sweat taste. In conclusion, we assumed that it will be possible to prepare the hydrolysates having functionality when soy-protein were hydrolyzed by these specific enzymes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.10
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• pp.1343-1348
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• 2006

This study was performed to investigate the effects of silk protein enzyme hydrolysates on blood glucose and serum lipid in db/db diabetic mice. Twelve week-old-male C57BL/KsJ db/db mice were divided into two groups: diabetic control group and 0.25% silk protein hydrolysates solution group, which were fed for 8 weeks. Body weight increased in the silk protein hydrolysates group compared with the diabetic control group. There were no differences in food and water intake between the diabetic control and the silk protein hydrolysates groups. The weight of liver increased in the silk protein hydrolysates group while that of kidney increased in the diabetic control group. The blood glucose level increased about 18.0% in the diabetic control group after 8 weeks while that in the silk protein hydrolysates group increased about 5.8%. Also, silk protein hydrolysates improved the glucose tolerance in C57BL/KsJ db/db mice. There was no difference in total cholesterol and non-HDL cholesterol concentration between the diabetic control and the silk protein hydrolysates group. Triglyceride concentration were lower in the silk protein hydrolysates group than in the diabetic control group (p<0.05) while HDL-cholesterol concentration were higher in the silk protein hydrolysates group than in the diabetic control group (p<0.05). This results suggest that administration of silk protein enzyme hydrolysates reduces significantly an increasing rate of 1]food glucose, decreases triglyceride, and increases HDL-cholesterol in C57BL/KsJ db/db mice.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.3
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• pp.229-235
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• 1992

Fish protein hydrolysates(FPH) prepared from defatted mackerel meal by proteases such as complex enzymes, bromelain, alcalase, $\alpha-chymotrypsin,$ trypsin, papain and pepsin were tested for inhibitory activity against angiotensin-I converting enzyme(ACE). Among proteases tested, the hydrolysates obtained from the treatment of complex enzymes or bromelain showed relatively higher activity. ACE inhibitory activity of the hydrolysates increased until hydrolysis of 8 hrs, and was stable by heat treatment for 20min at $100^{\circ}C.$ From the profiles of fractionation of the hydrolysates with Bio-gel P-2, the most active fraction had about MW 1,450 and it's amino acid was abundant in Asp, Glu, Lys, Leu, Val and Ala. $IC_{50}\;(amounts\;of\;inhibitors\;needed\;for\;50\%\;inhibition)$ of the active fraction of the hydrolysates obtained from the treatment of complex enzyme and bromelain was 90 and $130 {\mu}g,$ respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.1
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• pp.8-13
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• 2010

The angiotensin converting enzyme (ACE) inhibition effect of soybean protein isolate hydrolysate was studied using protease. Soybean protein isolate was hydrolysed by seven enzymes (Alcalase 2.4 L, Flavourzyme 500 MG, GC 106, Multifect Neutral, Neutrase 0.8 L, Papain 30,000 and Protamex), enzyme concentrations (0, 0.5, 1.0 and 1.5%), at various hydrolysis times (0, 1, 2, 3, 4, 5 and 6 hr) and suspension concentrations (1, 5, 7, 10 and 15%). Absorbance at 280 nm, brix and ACE inhibitory activity of soybean protein isolate hydrolysates were investigated. Absorbance at 280 nm and brix of Alcalase 2.4 L treatment were higher than other enzyme treatments. The optimum condition of hydrolysis was Alcalase 2.4 L, 1% enzyme concentration, 5% suspension concentration for 4 hr. $IC_{50}$ value of ACE inhibitory activity of soybean protein isolate hydrolysate was $79.94 {\mu}g/mL$. These results suggest that soybean isolate protein hydrolysate from Alcalase 2.4 L may be of benefit for developing antihypertensive therapeutics.

• The Korean Journal of Food And Nutrition
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• v.9 no.4
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• pp.392-397
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• 1996

To produce low salt fermented anchovy by an accelerated method with Asp. oryzae and Bacillus sp. koji, enzyme activity and variation of microflora during the 60 day fermentation were examined. Bacterial counts changed a little during the fermentation with the highest on day 40 for proteolytic and anaerobic bacteria and on day 20 for aerobic bacteria. Proteolytic, lipolytic, aerobic, and anaerobic bacteria counts were higher in the Bacillus sp. koji added anchovy paste than in others. The protease and lipase activities reached the highest point on day 20 and 30, respectively, and decreased gradually afterwards. The protease activity was higher in Asp. oryzae koji than in bacillus sp. koji, but the lipase activity was to the contrary.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.9
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• pp.1166-1171
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• 2006

This study was performed to investigate the effect of silk protein hydrolysates on blood glucose in diabetic mice (C57BL/KsJ db/db). The silk protein hydrolysates hydrolyzed by protease contains 87.52% of peptides of which molecular weight was below 2,000 dalton. The content of free amino acids was 14.80 g/100 g silk protein hydrolysates and major free amino acids were Pro, Thr, Arg and Ala. Silk protein hydrolysates were administered to the animals for 9 weeks at doses of 0.2, 0.5% and 0.8% solution. The body weight increase in the 0.5 and 0.8% fed groups were higher than control group. Food and water intake in the silk protein hydrolysates fed groups were lower than control group. The weight of liver was not different among groups, while the weight of kidney in control group was higher than silk protein hydrolysates fed groups. The blood glucose level in silk protein hydrolysates fed groups was lower than control group. In the glucose tolerance test, the blood glucose level in control group was the highest at 15 minutes after glucose injection while those in silk protein hydrolysates fed groups were the highest at 30 minutes. Results in this study suggest that silk protein hydrolysates show hypoglycemic effect in C57BL/KsJ db/db mice.

• Korean Journal of Food Science and Technology
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• v.22 no.3
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• pp.234-240
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• 1990

Attempts have been made to optimize the hydrolysis conditions of the oyster and the mussel by the commercial proteolytic enzymes. Raw materials were digested with seven different commercial enzymes, and their quality parameters measured in terms of degree of hydrolysis and content of free amino nitrogen, nucleic acid-related substances. and free amino acids as well as sensory evaluation of optimization of their hydrolysis conditions. As a result, following enzymes have been disclosed as effective for enzymatic digestion: MKC-HT proteolytic, alcalase 0.6L and thermease for the oyster whereas MKC-acid fungal protease and thermoase for the mussel, respectively.