• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.30 no.1
• /
• pp.79-87
• /
• 1997

A study on the processing method of anchovy hydrolysate paste (AHP) was carried out to improve the sensory quality of salted and fermented fish. Homogenized whole anchovy was hydrolyzed using commercial pretenses, Complex enzyme-2000 (CE, Pacific Chem. Co.) and Alcalase (AL, Novo), in a cylindrical vessel with 4 baffle plates and 6-bladed turbine impeller. Optimal pH, temperature, and enzyme concentration for the hydrolysis with CE and AL were $7.0,\;52^{\circ}C,\;7\%$, and $8.0,\;60^{\circ}C,\;6\%$, respectively. The rational amount of water for homogenization, agitation speed, and hydrolyzing time were $100\%\;(w/w)$, 100 rpm, and 210 min, respectively. To make the hydrolysate to paste type, it was effective to mix the additives, such as starch, soybean protein, agar, and carrageenan gum to the hydrolysate 5 min before the end of boiling at $100^{\circ}C$ for 30 min. Minimal NaCl concentration for long-term preservation was $15\%$, and this could be reduced to $12\%$ by adding $5\%$ of KCl. yield of the AHP based on the total nitrogen content was $94.6\~97.0\%,\;and\;86.0\~89.2\%$, of the nitrogen was amino nitrogen. Salinity, pH and histamine content of the AHP prepared with $12\%$ NaCl and $5\%$ KCl were $9.3\~9.9\%,\;6.1\~6.2$, and below 13 mg/100 g, respectively. The AHP was stable at $26{\pm}3^{\circ}C$ for 60 days on bacterial growth, and addition of $0.05\%$ of rosemary (Herbalox) extract was effective to inhibit the lipid oxidation of the AHP during storage.

• Fisheries and Aquatic Sciences
• /
• v.18 no.1
• /
• pp.13-20
• /
• 2015

Calculated chemical scores (computed in relation to the FAO/WHO reference protein) for salmon liver protein hydrolysates indicated that all amino acids (other than methionine and threonine) were present in adequate or excess quantities; thus, the raw liver material is a good source of essential amino acids. The hydrophobic amino acids contents in hydrolysates prepared from Oncorhynchus keta and O. gorbuscha were 38.4 and 39.1%, respectively. The proportion of released peptides exceeding 500 kDa was reduced when hydrolysates were treated with the commercial enzyme Alcalase, although proportions in the following MW ranges were elevated: 100-500 kDa and <50 kDa. The optimal conditions for enzymatic hydrolysis were as follows: pH 7.0, $50^{\circ}C$, and a reaction time of 1 h. Of the different proteases tested, Alcalase was the most efficient for production of salmon liver hydrolysate with the highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity. The hydrolysates prepared from salmon liver had a balanced amino acid composition. The liver protein hydrolysates contained low molecular weight peptides, some of which may be bio-active; this bio-active potential should be investigated. Inhibition of the DPPH radical increased with increased degree of hydrolysis (DH), regardless of protease type. DPPH radical scavenging abilities, antithrombotic effects and ${\alpha}$-glucosidase enzyme inhibition effects of O. keta liver hydrolysate increased in a dose-dependent manner. Thus, salmon liver hydrolysate may be useful in functional food applications and as a source of novel products.

• Fisheries and Aquatic Sciences
• /
• v.24 no.5
• /
• pp.197-206
• /
• 2021

Marine brown seaweeds are a source of functional ingredients with various biological properties. They have been used in the food and functional food industries. Brown seaweeds are divided into three parts of blades, stipe, and root. Normally seaweed blades were used as raw materials for biological research. However, there are limited uses on stipes of Ecklonia maxima (E. maxima) depending on the physicochemical, nutritional, and biological properties. Besides, the comparative studies of two structures of E. maxima, blades and stipe didn't discover previously. This study aimed to compare the potent antioxidant and anti-inflammatory activities of the two structures of E. maxima, blades and stipe in vitro studies to increase the utilization of the two structures of E. maxima. The enzyme-assisted hydrolysate from E. maxima showed significant antioxidant and anti-inflammatory activities. Among them, celluclast-assisted hydrolysate from E. maxima blades (EMBC) and viscozyme-assisted hydrolysate from E. maxima stipe (EMSV) expressed significant protection on hydrogen peroxide-induced oxidative stress. Moreover, EMBC and EMSV treatment remarkably reduced nitric oxide production by downregulation of pro-inflammatory cytokine expressions in lipopolysaccharide-stimulated Raw 264.7 cells. Especially EMBC showed strong inhibition on pro-inflammatory cytokine production compared to EMSV. Taken together research findings suggest that EMBC and EMSV possessed potent antioxidant and anti-inflammatory properties and may be utilized as functional ingredients in the food and functional food sectors.

• Korean Journal of Food Science and Technology
• /
• v.29 no.6
• /
• pp.1316-1318
• /
• 1997

The isolated ${\kappa}-Casein$ on gel permeation chromatography was hydrolyzed by chymosin, trypsin, and pepsin. The 3% TCA soluble portion of the hydrolysates were dialyzed on the angiotensin-I converting enzyme (ACE) inhibition rate (%,) and inhibitory activity $(IC_{50})$ were determined. The trypsin hydrolysate exhibited the highest ACE inhibition rate while the chymosin hydrolysation showed the lowest activity. The hydrolysate was dialyzed using dialysis membrane with various molecular cut-offs, and $IC_{50}$ was determined. As the pore size of the dialysis tubing increased, the ACE inhibitory activity decreased.

• Applied Biological Chemistry
• /
• v.42 no.1
• /
• pp.49-57
• /
• 1999

Enzymatic hydrolysis with tuna pyloric caeca crude enzyme(TPCCE) was performed to recover a protein hydrolysate from hoki frame, fish processing by-product. Optimum hydrolytic conditions were pH 10.0, temperature $50^{\circ}C$, and incubation time 12 hrs, and then the degree of hydrolysis was about 60%. The yield of the hydrolysate from hoki frame by enzymatic hydrolysis was approximately 77% on a dry weight basis. The prepared protein hydrolysates were also fractionated through a series of 30, 10, 5 and 1 kDa molecular weight cut-off (MWCO) membranes in order to investigate the effect of their functionalities according to the difference of their molecular size. As the result of studying functionalities of the hydrolysates, 1 K hydrolysate showed the highest solubility over all pHs, and 30 and 10 K hydrolysate showed more excellent emulsifying property and whippability than the other hydrolysates.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.44 no.2
• /
• pp.118-125
• /
• 2011

In this study, an angiotensin I-converting enzyme (ACE) inhibitor from squid skin was purified and characterized. Squid (Todarodes pacificus) skin protein isolates were hydrolyzed using six commercial proteases: alcalase, ${\alpha}$-chymotrypsin, neutrase, papain, pepsin, and trypsin. The peptic hydrolysate had the highest ACE inhibitory activity. The ACE inhibitory peptide was purified using Sephadex G-25 column chromatography and reverse phase high-performance liquid chromatography (HPLC) with a $C_{18}$ column. The purified ACE inhibitory peptide was identified and sequenced, and found to consist of seven amino acid residues: Ser-Ala-Gly-Ser-Leu-Val-Pro (657Da). The $IC_{50}$ value of the purified ACE inhibitory peptide was 766.2 ${\mu}M$, and Lineweaver-Burk plots suggested that the purified peptide acts as a noncompetitive ACE inhibitor. These results suggest that the ACE inhibitory peptide purified from the peptic hydrolysate of squid skin may be of benefit in developing antihypertensive drugs and functional foods.

• BMB Reports
• /
• v.35 no.2
• /
• pp.239-243
• /
• 2002

Angiotensin I that converts the enzyme (ACE) inhibitory peptide, Gly-Pro-Leu, previously purified and identified from the Alaskan pollack skin gelatin hydrolysate, were synthesized. In addition, the peptides Gly-Leu-Pro, Leu-Gly-Pro, Leu-Pro-Gly, Pro-Gly-Leu, Pro-Leu-Gly, Gly-Pro, and Pro-Leu, which consisted of glycine, proline, and leucine, were synthesized by the solid-phase method. The $IC_{50}$ values of each tripeptide - namely Leu-Gly-Pro, Gly-Leu-Pro, Gly-Pro-Leu, Pro-Leu-Gly, Leu-Pro-Gly, and Pro-Gly-Leu - were 0.72, 1.62, 2.65, 4.74, 5.73, and $13.93{\mu}M$, respectively. The ACE inhibitory activity of these tripeptides was higher than that of dipeptides, such as Gly-Pro and Pro-Leu with $IC_{50}$ values of 252.6 and $337.3\;{\mu}M$, respectively. Among the tripeptides, Leu-Gly-Pro and Gly-Leu-Pro had higher inhibitory activity than Gly-Pro-Leu that was isolated from the Alaskan pollack skin gelatin hydrolysate. Among the different types of tripeptides that were examined, the highest ACE inhibitory activity was observed for Leu-Gly-Pro. It had the leucine residue at the N-terminal and proline residue at the C-terminal.

• Food Science of Animal Resources
• /
• v.43 no.1
• /
• pp.184-194
• /
• 2023

Recently, interest in food-derived bioactive peptides as promising ingredients for the prevention and improvement of hypertension is increasing. The purpose of this study was to determine the structure and antihypertensive effect of an antioxidant peptide purified from velvet antler in a previous study and evaluate its potential as a various bioactive peptide. Molecular weight (MW) and amino acid sequences of the purified peptide were determined by quadrupole time-of-flight electrospray ionization mass spectroscopy. The angiotensin I-converting enzyme (ACE) inhibition activity of the purified peptide was assessed by enzyme reaction methods and in silico molecular docking analysis to determine the interaction between the purified peptide and ACE. Also, antihypertensive effect of the purified peptide in spontaneously hypertensive rats (SHRs) was investigated. The purified antioxidant peptide was identified to be a pentapeptide Asp-Asn-Arg-Tyr-Tyr with a MW of 730.31 Da. This pentapeptide showed potent inhibition activity against ACE (IC₅₀ value, 3.72 μM). Molecular docking studies revealed a good and stable binding affinity between purified peptide and ACE and indicated that the purified peptide could interact with HOH2570, ARG522, ARG124, GLU143, HIS387, TRP357, and GLU403 residues of ACE. Furthermore, oral administration of the pentapeptide significantly reduced blood pressure in SHRs. The pentapeptide derived from enzymatic hydrolysate of velvet antler is an excellent ACE inhibitor. It might be effectively applied as an animal-based functional food ingredient.

• Food Science of Animal Resources
• /
• v.32 no.5
• /
• pp.652-658
• /
• 2012

This study was carried out to identify the ACE (Angiotensin converting enzyme) inhibitory activity of casein hydrolysates for development of anti-hypertensive hydrolysates. Sodium caseinate was treated with six kinds of commercial proteases such as Flavourzyme, Protamex, Neutrase 1.5, Alcalase, Protease M, and Protease S for 8 h individually, and was then treated with the enzyme combination for 4 h at $45^{\circ}C$. The hydrolysate which had the highest ACE inhibitory effect was then hydrolysed successively with three digestive enzymes: pepsin, trypsin, and ${\alpha}$-chymotrypsin, at $37^{\circ}C$ for 4 h under conditions mimicking those of the gastrointestinal tract. UF (ultra filtration) treatment was applied to one of the secondary hydrolysates to determine ACE inhibitory activity. When sodium caseinate was hydrolysed by commercial proteases, the degree of hydrolysis (DH) showed 2.54 to 4.25% and after secondary hydrolysis, DH showed 4.30 to 5.22%. ACE inhibitory activity and $IC_{50}$ values decreased, and inhibition rates increased during hydrolysis. Protamex treatment showed the lowest $IC_{50}$ value ($516{\mu}g/mL$) and Flavourzyme hydrolysate showed the highest $IC_{50}$value ($866{\mu}g/mL$). As the first hydrolysate was treated with Flavourzyme, the ACE inhibitory activity increased. Neutrase hydrolysate had the highest activity with an $IC_{50}$ value ($282{\mu}g/mL$). When Neutrase plus Flavourzyme treatment was hydrolyzed by digestive enzymes, the $IC_{50}$ value ($597{\mu}g/mL$) was decreased statistically (p<0.05). As Neutrase plus Flavourzyme hydrolysate is treated by UF with MW cut-off 10,000, permeate showed $273{\mu}g/mL$ of $IC_{50}$ value, showed no difference, but retentate which has over MW 10,000 showed statistically different $IC_{50}$ value, $635{\mu}g/mL$ (p<0.05).

• KSBB Journal
• /
• v.28 no.2
• /
• pp.131-136
• /
• 2013

The hydrolysates prepared with various enzyme digestion of Capsosiphon fulvescens were used to measure the inhibitory effects against angiotensin I converting enzyme (ACE). The commercially available enzymes such as Celluclast, Viscozyme, Lysing enzyme, Flavourzyme, Alcalase and Pectinex were used to digest C. fulvescens and produce hydrolysates. The maximum ACE inhibitory activity was observed using Alcalase hydrolysis (72.9%). The optimal conditions of Alcalase extraction were pH 8.0 and extraction time for 12 hr. The hydrolysates were fractionated using preparative-LC and anion-exchange chromatography on DEAE-cellulose and the fraction B and B-2 were isolated. The ACE inhibitory activity of fraction B-2 by anion-exchange chromatography was 82.6%. The molecular weight of fraction B-2 estimated using size exclusion chromatography was about 1 kDa. The monosaccharide composition of the fraction B-2 was determined to be mannose (1.1%), glucuronic acid (1.3%), galactose (1.3%) and glucose (96.3%).