• Preventive Nutrition and Food Science
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• v.10 no.2
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• pp.134-139
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• 2005

Seven brown algal species (Ecklonia cava, Ishige okamurae, Sargassum fulvellum, Sargassum horneri, Sargassum coreanum, Sargassum thunbergii and Scytosiphon lomentaria) were hydrolyzed using five proteases (Protamex, Kojizyme, Neutrase, Flavourzyme and Alcalase) and screened for angiotensin 1-converting enzyme (ACE) inhibitory activities. Most algal species examined showed good ACE inhibitory activities after the enzymatic hydrolysis. However, E. cava was the most potent ACE inhibitor of the seven species. Flavourzyme digest of E. cava exhibited an $IC_{50}$ of around $0.3\;{\mu}g/mL$ for ACE; captopril has an $IC_{50}$ of $\~0.05\;{\mu}g/mL$. The Flavourzyme digest was separated to three fractions by an ultrafiltration membrane (5, 10, 30 kDa MWCO) system according to the molecular weights. The active components were mainly concentrated in >30 kD fraction which are composed of the highest protein content $(27\%)$ and phenolic content (261 mg/100 mL) compared to the other two smaller molecular weight fractions. Therefore, the active compounds appear to be relatively high molecular weight complex molecules associated with protein (glycoprotein) and polyphenols. Therefore, E. cave is a potential source of antihypertensive compound.

• Preventive Nutrition and Food Science
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• v.15 no.4
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• pp.309-315
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• 2010

A grilled-type shrimp flavor was developed through the Maillard reaction to reduce or mask fish odor or off-flavor in seafood. Model systems were created by using enzymatic hydrolysate of shrimp and adding precursors to increase flavor quality and stability. Amino acid precursors such as cysteine and methionine, sugar precursors such as glucose, xylose, ribose, and sucrose, and one particular compound of glucosamine were tried and their flavor qualities were tested by sensory evaluation. Also, the optimum reaction condition was investigated using the pH values of pH 5, 6, 7, and 8 with reaction times of 1 hr, 2 hr and 3 hr after the best precursors were determined. The best condition of the precursors for grilled-type shrimp flavor was the mixtures of methionine, threonine, xylose, and glucosamine. The optimum reaction condition was at pH 8.0 and 2 hr reaction time.

• Preventive Nutrition and Food Science
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• v.15 no.4
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• pp.304-308
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• 2010

Boiled-type shrimp flavor was developed using Maillard reaction to reduce or mask fish odor or off-flavor in seafood. Model systems were created using enzymatic hydrolysate of shrimp and adding precursor compounds to increase flavor quality and stability. Amino acid precursors of cysteine and methionine and sugar precursors such as glucose, xylose, ribose and sucrose were tried and their flavor qualities were tested by sensory evaluation. After the optimal precursors were determined, the optimum reaction condition was investigated using pHs of 5, 6, 7, and 8 and reaction times of 1, 2 and 3 hours. The best precursors for boiled-type shrimp flavor were methionine and sucrose. The optimum reaction condition was pH 8.0 and a one hour reaction time.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.4
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• pp.458-465
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• 1999

Distribution of the proteolytic activities of crude pretense extracted from the viscera of ten kinds of fish was examined. Their proteolytic activities on proteinous substrates (azocasein, hemoglobin, and casein) from the viscera of anchovy, bastard flatfish, mackerel and red sea bream were higher than those of other fishes, and the crude pretenses were further fractoinated with acetone or ammonium sulfate. Optimum concentrations for pretenses fractionation were $0\~55\%$ for acetone and $30\~70\%$ for ammonium sulfate. The fractionated viscera pretense of mackerel showed the highest proteolytic activity among four kinds of fishes. Activities of cathepsin D- and pepsin-like enzymes at pH 3.0, cathepsin L-, B-, H- and G-like enzyme at pH 6,0, and Hypsin- and chymotrypsin- like enzymes (pH 8.0) were detected in the fractionated viscera pretense, whereas activities of cathepsin L- and chymoeypsin-like enzyme were observed in commercial pretenses. Proteolytic activities of Alcalase, Protamex, and Aroase AP-10 for azocasein were slightly higher than the fractionated viscera pretenses, but their amidolytic activities at pH 6.0 and 8.0 toward synthetic substrates were lower than counterpart. The fractionated pretenses from fish viscera would be utilized as commercial pretenses.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.2
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• pp.127-133
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• 2019

Seahorses have long been used as ornamental and medicinal products. The sea horse Hippocampus abdominalis has a beautiful color and unique shape and is also used for ornamental purposes and as a traditional medicine in China. This study examined the value of H. abdominalis as a health functional food or food additive. H. abdominalis was hydrolyzed using seven proteases: flavourzyme, neutrase, alcalase, trypsin, kojizyme, pepsin and protamex. The yields of all of the enzyme hydrolysates were higher than that of the aqueous extract. Of the enzymatic hydrolysates, seahorse Protamex hydrolysate (SHP) gave the highest yield and had excellent antioxidant and angiotensin-I converting enzyme inhibitory activities. It protected Vero cells against oxidative by 2,2-azobis-(2-amidinopropane) dihydrochloride (AAPH) and antihypertension in Spontaneously Hypertensive Rats. This study attempted to demonstrate H. abdominalis as a health functional food or food additive in the future.

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

• Journal of Practical Agriculture & Fisheries Research
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• v.14 no.1
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• pp.93-105
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• 2012

This study was carried out to prepare anchovy hydrolysates by using Alcalase, Neutrase and Protamex, and to investigate its quality characteristics. The major free amino acids were glutamic acid and lysine. The total amino acid content of anchovy hydrolysate were glutamic acid(12.6%), lysine(8.56%), valine(7.06%), aspartic acid(5.73%). Major nucleotides content of anchov hydrolysate were 5'-IMP (22.462 mg/100g), 5'-GMP (18.674 mg/100g) and 5'-UMP (1.25 mg/100g). Histamine content of anchovy hydrolysate was 18.1 mg/100g. These results suggested that anchovy hydrolysate could be used as a sauce of basic seasoning.

• Food Science of Animal Resources
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• v.44 no.4
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• pp.885-898
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• 2024

Ovomucin (OM), which has insoluble fractions is a viscous glycoprotein, found in egg albumin. Enzymatic hydrolysates of OM have water solubility and bioactive properties. This study investigated that the immunostimulatory effects of OM hydrolysates (OMHs) obtained by using various proteolytic enzymes (Alcalase^®, bromelain, α-chymotrypsin, Neutrase^®, pancreatin, papain, Protamax^®, and trypsin) in RAW 264.7 cells. The results showed that OMH prepared with pancreatin (OMPA) produced the highest levels of nitrite oxide in RAW 264.7 cells, through upregulation of inducible nitric oxide synthase mRNA expression. The production of pro-inflammatory cytokines such as tumor necrosis factor-α and interleukin-6 were increased with the cytokines mRNA expression. The effect of OMPA on mitogen-activated protein kinase signaling pathway was increased the phosphorylation of p38, c-Jun NH2-terminal kinase, and extracellular signal-regulated kinase in a concentration-dependent manner. Therefore, OMPA could be used as a potential immune-stimulating agent in the functional food industry.

• Food Science and Preservation
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• v.22 no.2
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• pp.297-302
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• 2015

Calcium is one of the essential mineral for the humans due to its crucial physiological functions in the body. Calcium deficiency results in many diseases, such as osteoporosis. Therefore, calcium supplements are available as a functional food. However, most calcium supplements in the market have a limitation due to poor absorption and low bioavailability. Thus, calcium-chelated peptides for improving the absorption rate of calcium have been isolated from foods including porcine meat and bone meal (MBM), and mussel using the enzymatic hydrolysis of their protein. The hydrolysates of food were ultra-filtered in order to obtain small peptides less than 3 kDa and the Ca-binding peptides were isolated via the anion exchange chromatography. The binding activity and concentration of Ca-binding pepetides were determined. In particular, the MBM and mussel protein hydrolysates were fractionated by mono Q and Q-Sepharose, respectively. As a result, among the fractions, the fractions of MBM F2 and mussel F3 showed the highest Ca-binding activity. These results suggest that MBM and mussel protein hydrolysates can be used as calcium supplements.

• Journal of Microbiology and Biotechnology
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• v.28 no.1
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• pp.1-11
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• 2018

An antioxidant peptide derived from Pinctada fucata meat using an Alcalase2.4L enzymatic hydrolysis method (named AOP) and identified by LC-TOF-MS has promising clinical potential for generating cosmetic products that protect skin from sunshine. To date, there have been few published studies investigating the structure-activity relationship in these peptides. To prepare antioxidant peptides better and improve their stability, the design and expression of an antioxidant peptide from Pinctada fucata (named DSAOP) was studied. The peptide contains a common precursor of an expression vector containing an ${\alpha}$-helix tandemly linked according to the BamHI restriction sites. The DNA fragments encoding DSAOP were synthesized and subcloned into the expression vector pET-30a (+), and the peptide was expressed mostly as soluble protein in recombinant Escherichia coli. Meanwhile, the DPPH radical scavenging activity, superoxide radical scavenging activity, and hydroxyl radical scavenging activity of DSAOP $IC_{50}$ values were $0.136{\pm}0.006$, $0.625{\pm}0.025$, and $0.306{\pm}0.015mg/ml$, respectively, with 2-fold higher DPPH radical scavenging activity compared with chemosynthesized AOP (p < 0.05), as well as higher superoxide radical scavenging activity compared with natural AOP (p < 0.05). This preparation method was at the international advanced level. Furthermore, pilot-scale production results showed that DSAOP was expressed successfully in fermenter cultures, which indicated that the design strategy and expression methods would be useful for obtaining substantial amounts of stable peptides at low costs. These results showed that DSAOP produced with recombinant Escherichia coli could be useful in cosmetic skin care products, health foods, and pharmaceuticals.