• Food Science and Biotechnology
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• v.17 no.4
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• pp.873-877
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• 2008

Native soy protein isolate (SPI) was hydrolyzed with 4 different proteolytic enzymes, including bromelain, papain, Neutrase, and Flavourzyme. SPI hydrolysates with the degree of hydrolysis (DH) in range of 6 to 15% were prepared by each enzyme. The angiotensin 1 converting enzyme (ACE) inhibitory and the antioxidant activities of the SPI hydrolysates, such as superoxide dismutase-like activity and inhibition of the linoleic acid autoxidation, were evaluated. Overall, as the DH increased, all evaluated bioactivities of the SPI hydrolysates significantly increased. The significantly highest ACE inhibitory and antioxidant activities were found in hydrolysates made with papain and bromelain, respectively. SPI hydrolysates by Flavourzyme showed the significantly lowest activity in all tested bioactivities. The results suggested that ACE inhibitory and antioxidant activities of SPI hydrolysates were determined by the DH and by the enzyme used.

• The Korean Journal of Food And Nutrition
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• v.33 no.2
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• pp.167-173
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• 2020

To increase the functional material content of soybean, a repetitive steaming and drying process was used. We investigated the changes in the total polyphenol content, the antioxidant activity, and the angiotensin-I converting enzyme (ACE) inhibition in soybean following nine rounds of steaming and drying. Soybean was steamed 9 times for 2 h and then dried 9 times from 55℃ to 73℃ for 3 h. The total polyphenol content in the soybean reached a maximum value of 60.47 mg GAE eq./100 g at 73℃ while the total polyphenol content in the raw soybean reached 25.17 mg GAE eq./100 g. In the raw soybean samples, the DPPH radical scavenging activity (5 mg/mL) was 8.04% but it increased by 43.29% after drying 9 times to 73℃. ABTS radical scavenging activity also improved following 9 rounds of steaming and drying. ACE inhibitory activity of the soybean dried 9 times at 73℃ was 58.94% at 10 mg/mL. These results showed that steaming and drying soybean 9 times enhanced the antioxidant activity and the ACE inhibitory activity of soybean. Therefore, more research on the biological and anti-hypertensive activity of soybean using this steaming and drying method is necessary.

• Journal of Microbiology and Biotechnology
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• v.12 no.1
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• pp.59-64
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• 2002

An angiotensin I-converting enzyme (EC 3.4.15.1) (ACE), which can convert inactive angiotensin I into angiotensin II, a vasoconstrictor, is one of the key enzymes in controlling hypertension. It is suggested that the inhibition of ACE prevents hypertension, and many inhibitory peptides have already been reported. In the current study, oligonucleotides encoding ACE inhibitory peptides (IY, VKY) were chemically synthesized and designed to be multimerised due to isoschizomer sites (BamHI, BglII). The cloned gene named AP3 was multimerised up to 6 times in pBluescript and expressed in BL2l containing pGEX-KG. The fusion protein (GST-AP3) was easily purified with a high recovery by an affinity resin, yielding 38 mg of synthetic AP3 from a 1-1 culture. The digestion of AP3 by chymotrypsin exhibited an $IC_50$ value of $18.53{\mu}M$. In conclusion, the present experiment indicated that AP3 could be used as a dietary antihypertensive drug, since the potent ACE inhibitory activity of AP3 could be activated by chymotrypsin in human intestine.

• Korean Journal of Pharmacognosy
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• v.42 no.1
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• pp.61-67
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• 2011

In this study, we evaluated the bioactivities of methanol extract and its solvent fractions of Sonchus asper (L.) Hill. The EtOAc fraction of S. asper exhibited more strong antioxidant activity than other extracts as evidenced by the strongest 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging activity with a $EC_{50}$ value at $33.55\;{\mu}g/mL$ and reducing power, the total polyphenol (180.71 mg GAE/g) and flavonoid contents (145.86 mg QE/g) of S. asper extract were higher than other extracts. The EtOAc fraction of the S. asper also showed 47.38% mushroom tyrosinase inhibition activity, 56.22% ${\alpha}$-glucosidase inhibition and 46.58% ${\alpha}$-amylase inhibition ratio at 1 mg/mL. Both methylene chloride and EtOAc fractions of methanol extract of S. asper effectively reduced of the 86.34% and 62.03% angiotensin I converting enzyme (ACE) activity at 2 mg/mL, respectively. These findings suggest that the EtOAc fraction of the S. asper could be a potential antioxidant in food additive, medicinal, and industry product.

• Journal of Microbiology and Biotechnology
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• v.25 no.8
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• pp.1315-1320
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• 2015

To enhance the γ-aminobutyric acid (GABA) content, the optimized fermentation of soybean with added sea tangle extract was evaluated at 30℃ and pH 5.0. The medium was first inoculated with Aspergillus oryzae strain FMB S46471 and fermented for 3 days, followed by the subsequent inoculation with Lactobacillus brevis GABA 100. After fermentation for 7 days, the fermented soybean showed approximately 1.9 g/kg GABA and exhibited higher ACE inhibitory activity than the traditional soybean product. Furthermore, several peptides in the fraction containing the highest ACE inhibitory activity were identified. The novel fermented soybean enriched with GABA and ACE inhibitory components has great pharmaceutical and functional food values.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.5
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• pp.871-877
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• 1996

Hot-water extract and enzymatic hydrolysate prepared from fresh water fish such as carp, snakehead, eel and israeli cart were tested for inhibitory activity against Angiotensin I converting enzyme(ACE). ACE inhibitory activity of enzymatic hydrolysate was higher than that of hot-water extract, and was the highest in enzymatic hydrolysate of carp among the tested samples. ACE inhibitory activity of 70% ethanol soluble fraction was higher than that of precipitated fraction, the highest in enzymatic hydrolysate of carp. Molecular weight of active fraction was about 1,400 in hot-water extract and slightly above in enzymatic hydrolysate. Amino acid of active fraction of hot-water extract was abundant in glycine, alanine, leucine and proline, whereas amino acids of aspartic acid, glutamic acid, glycine, alanine, valine, leucine and proline were abundant in enzymatic hydrolysate. $IC_{50}$/(amounts of inhibitors need for 50% inhibition) of hot-water extract was the range of 50.3~56.9$\mu\textrm{g}$, those of enzymatic hydrolysate 42.6~57.7$\mu\textrm{g}$.

• 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.

• Korean Journal of Food Science and Technology
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• v.27 no.6
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• pp.978-984
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• 1995

This study was conducted to investigate the physiological functionality of the hot water and 70% acetone extracts obtained from the pine needle and mugwort. Flavanol tannin content was above 60% of the total polyphenol in pine needle extracts. 70% Acetone extract from pine needle exhibited inhibition percentage of about 82.2% on the mutagenicity of Trp-P-1. Angiotensin I converting enzyme(ACE) inhibition activity was 61% and 50% in the hot water extract and in the 70% acetone extract respectively. Electron donating ability(EDA) of the hot water and 70% acetone extracts obtained from the pine needle was significantly good above 80%. 70% Acetone extract from pine needle showed inhibitary effect against the polyphenol oxidase(PPO) of water dropwort. The nitrite scavenging ability was appeared in all the extracts examined and it showed $80{\sim}90%$ at pH 3.0. The oxidative stability was determined by POV. Results showed that ethyl acetate fraction is better antioxidants than chloroform and butanol fractions in the soybean oil. Then, in the mugwort extracts, antimutagenicity of 70% acetone extract was similar to that of pine needle. Ratio of ACE inhibition activity was higher than that of pine needle extracts. EDA of hot water and 70% acetone extracts was 45%. Extracts from the mugwort were lower in nitrite scavenging ability about $20{\sim}30%$ than extracts from pine needle.

• Food Science of Animal Resources
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• v.43 no.1
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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.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.10a
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• pp.183-184
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• 2001

Angiotensin I converting enzyme (ACE) in renin-angiotensin system is a cause of essential hypertension, which covers most hypertension, one of the major adult diseases. Thus, the inhibition of ACE would be indispensable for the prevention and cure of hypertension. Therefore, a lot of studies on the ACE inhibitor have been conducted. Peptides from the protein hydrolysate have been reported as an remarkable inhibitor. Especially, various ACE inhibitory peptides were isolated and identified from marine products for their utilization as value added products. (omitted)