• Korean Journal of Fisheries and Aquatic Sciences
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• v.40 no.6
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• pp.350-355
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• 2007

The optimal substrates and reaction flavoring conditions were examined to develop pearl oyster extract (POE) flavor using the Maillard reaction under a model system. The sugar for the Maillard reaction was glucose, and the amino acid was cysteine, with glycine as the reaction substrate. A three-dimensional response surface method was used to monitor the dynamic changes of the substrates during the Maillard reaction. To enhance the flavor of POE, a two-step enzymatic hydrolysate (Brix $20^{\circ}$) was reacted with the precursors (1:1, v/v). A 2:1:1 mixture of 0.4 M glucose:0.4 M glycine:0.4 M cysteine (v/v) was selected as a suitable reaction system for the reappearance of baked potato odor and boiled meat odor, and masking the shellfish odor. The two-step enzymatic hydrolysate and selected precursors were reacted in a high-pressure reactor to optimize the reaction parameters. The optimum conditions were 150 minutes at $120\;^{\circ}C$ and pH 7.0. The pH was the most critical factor for the response of the baked potato odor and masking the shellfish odor, while the reaction time affected the reappearance of the boiled meat odor.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.1
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• pp.123-131
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• 2020

In this study, we investigated the protective effects of a Neutrase enzymatic hydrolysate derived from Korea pen shell Atrina pectinata (APN) against hydrogen peroxide (H₂O₂)-induced oxidative damage in hepatocytes. First, we confirmed that APN has antioxidant activities by scavenging 2,2-azino-bis (3-ethylbenzthiazoline)-6-sulfonic acid radical (ABTS⁺) and H₂O₂ and increasing oxygen radical absorbance capacity (ORAC) value. Also, the treatment of APN increased the cell viability by reducing the intracellular reactive oxygen species (ROS) production in H₂O₂-stimulated hepatocytes. In addition, APN decreased the sub-G₁ DNA contents and the apoptotic body formation increased by H₂O₂ stimulation. Moreover, APN modulated the protein expression of apoptosis related molecules (Bcl-2, Bax and p53) by suppressing the activation of nuclear factor NFkB and ERK/p38 signaling in H₂O₂-stimulated hepatocytes. Furthermore, APN led to the activation of Nrf2/HO-1signaling known as antioxidant systems. These results suggest APN protects hepatocytes against oxidative damages caused by H₂O₂ stimulation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.5
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• pp.707-716
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• 2020

Red sea cucumber Stichopus japonicus, was dried using three methods-far-infrared ray, vacuum, and freeze drying and then enzymatically hydrolyzed using nine proteases: Alcalase, Flavourzyme, Kojizyme, Neutrase, Protamex, trypsin, α-chymotrypsin, and papain. In addition, the potential ability of hydrolysates to inhibit lipid accumulation in 3T3-L1 adipocytes was evaluated. The yield of hydrolysates from red sea cucumbers dried using each method was higher than that of the distilled water extract, and protein contents were either similar or higher. The hydrolysates that exhibited inhibitory effects on lipid accumulation, as demonstrated via Oil red O staining, were those obtained by far-infrared ray drying coupled with Alcalase, Flavourzyme, Kojizyme, or Neutrase treatment. In addition to the advantages of far-infrared drying and the characteristics of Flavourzyme, the Flavourzyme hydrolysate of far-infrared-dried red sea cucumber showed the highest inhibitory effect on lipid accumulation. In addition, this hydrolysate significantly decreased the expression of the protein factor fatty acid-binding protein 4, which is related to the late differentiation of 3T3-L1 adipocytes. Taken together, these results suggest that Flavourzyme hydrolysates from farinfrared-dried red sea cucumber may be used as a functional food and/or a pharmaceutical ingredient for the inhibition of lipid accumulation.

• Food Science of Animal Resources
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• v.39 no.6
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• pp.966-979
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• 2019

Muscle-based by-products are often undervalued although commonly reported having a high amount of natural bioactive peptides. In this study, elastin was isolated from the protein of broiler hen skin while its hydrolysate was prepared using Elastase. Assessment of antioxidative properties of elastin-based hydrolysate (EBH) was based on three different assays; 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) radical, 2,2'-azinobis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical and metal chelating ability. The EBH was purified further using ultrafiltration, gel filtration and Reverse- Phase High-Performance Liquid Chromatography (RP-HPLC). The IC₅₀ of ABTS radical activities for EBH were decreased as EBH further purified using ultrafiltration (EBH III; 0.66 mg/mL)>gel filtration (EB-II; 0.42 mg/mL)>RP-HPLC (EB-II4; 0.12 mg/mL). The sequential identification of the peptide was done by matrix-assisted laser desorption/ionization time-of-flight/time-of-flight mass spectrometry (MALDI-TOF/ TOF-MS) of the potent fractions obtained from RP-HPLC (EB-II4). The presence of hydrophobic amino acids (Val and Pro) in the peptide sequences could potentially contribute to the high antioxidant activity of EBH. The sequences GAHTGPRKPFKPR, GMPGFDVR and ADASVLPK were identified as antioxidant peptides. In conclusion, the antioxidative potential from poultry skin specifically from elastin is evident and can be explored to be used in many applications such as health and pharmaceutical purposes.

• Journal of Environmental Science International
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• v.19 no.10
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• pp.1307-1314
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• 2010

This study was conducted to isolate and characterize a novel feather-degrading bacterium producing keratinase activity. A strain K9 was isolated from soil at poultry farm and identified as Xanthomonas sp. K9 by phenotypic characters and 16S rRNA gene analysis. The cultural conditions for the keratinase production were 0.3% fructose, 0.1% gelatin, 0.04% $K_2HPO_4$, 0.06% $KH_2PO_4$, 0.05% NaCl and 0.01% $FeSO_4$ with an initial pH 8.0 at $30^{\circ}C$ and 200 rpm. In an optimized medium containing 0.1% chicken feather, production yield of keratinase was approximately 8-fold higher than the yield in basal medium. The strain K9 effectively degraded chicken feather meal (67%) and duck feather (54%), whereas human nail and human hair showed relatively low degradation rates (13-22%). Total free amino acid concentration in the cell-free supernatant was about 25.799 mg/l. Feather hydrolysate produced by the strain K9 stimulated growth of red pepper, indicating Xanthomonas sp. K9 could be not only used to increase the nutritional value of chicken feather but also a potential candidate for the development of natural fertilizer applicable to crop plant soil.

• Food Science of Animal Resources
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• v.38 no.6
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• pp.1144-1154
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• 2018

Both the calcium and collagen in bone powder are hard to be absorbed by the body. Although enzymatic hydrolysis by protease increased the bio-availability of bone powder, it was a meaningful try to further increase $Ca^{2+}$ release, oligopeptide formation and antioxidant activity of the sheep bone hydrolysate (SBH) by lactic acid bacteria (LAB) fermentation. Lactobacillus helveticus was selected as the starter for its highest protease-producing ability among 5 tested LAB strains. The content of liberated $Ca^{2+}$ was measured as the responsive value in the response surface methodology (RSM) for optimizing the fermenting parameters. When SBH (adjusted to pH 6.1) supplemented with 1.0% glucose was inoculated 3.0% L. helveticus and incubated for 29.4 h at $36^{\circ}C$, $Ca^{2+}$ content in the fermented SBH significantly increased (p<0.01), and so did the degree of hydrolysis and the obtaining rate of oligopeptide. The viable counts of L. helveticus reached to $1.1{\times}10^{10}CFU/mL$. Results of Pearson correlation analysis demonstrated that LAB viable counts, $Ca^{2+}$ levels, obtaining rates of oligopeptide and the yield of polypeptide were positively correlated with each other (p<0.01). The abilities of SBH to scavenge the free radicals of DPPH, OH and ABTS were also markedly enhanced after fermentation. In conclusion, L. helveticus fermentation can further boost the release of free $Ca^{2+}$ and oligopeptide, enhance the antioxidant ability of SBH. The L. helveticus fermented SBH can be developed as a novel functional dietary supplement product.

• Journal of Marine Bioscience and Biotechnology
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• v.10 no.2
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• pp.62-72
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• 2018

An active ingredient with hyaluronidase (HAse) inhibitory effect is one of the anti-aging approaches in cosmeceuticals. Here, red sea cucumbers (RSCs), Stichopus japonicus, from Jeju Island were evaluated to examine their HAse inhibitory and antioxidant activity effect. In this study, RSCs were extracted by six enzymatic hydrolysis (Alcalase; Al, Trypsin; Try, Neutrase; Neu, Pepsin; Pep, Alpha-chymotrypsin; Chy and Protamex; Pro). Alcalase hydrolysate (AlH) showed the highest antioxidant capacities for both of oxygen radical absorbance capacity (ORAC) and trolox equivalent antioxidant capacity (TEAC) methods, compared to those of other hydrolysates, at $66.59{\pm}0.78{\mu}M\;TE/mg$ and $135.78{\pm}3.24{\mu}M\;TE/mg$, respectively. Furthermore, AlH performed the highest capacity of HAse inhibitory with $IC_{50}$ value of 3.21 mg/ml. Thus, RSCs hydrolyzed by Al were chosen to determine the cellular antioxidant activity and hyaluronic acid (HA) production effect on Human immortalized keratinocyte cell line (HaCaT). The results showed that AlH improved the cell viabilities and intracellular reactive oxygen species (ROS) induced by 2,2'-Azobis(2-amidinopropane) dihydrochloride (AAPH) were significantly decreased. In addition, AlH increased HA amount by regulating HYAL2 and HAS2 expressions in the HaCaT cells. Taken together, AlH of RSCs collected from Jeju Island showed HAse inhibitory and antioxidant activities against skin-aging which shows its potentials can be an optional natural bioactive ingredient for novel cosmeceuticals.

• Food Science of Animal Resources
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• v.43 no.4
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• pp.594-611
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• 2023

Whey protein (WP) has nutritional value, but the presence of β-lactoglobulin (β-LG) and α-lactalbumin (α-LA) cause allergic reactions. In this study, hypoallergenic whey protein hydrolyate (HWPH) was prepared by decomposing β-LG and α-LA of WP using exo- and endo-type proteases. The enzyme mixing ratio and reaction conditions were optimized using response surface methodology (RSM). Degradation of α-LA and β-LG was confirmed through gel electrophoresis, and digestion, and absorption rate, and immunostimulatory response were measured using in vitro and in vivo systems. Through RSM analysis, the optimal hydrolysis conditions for degradation of α-LA and β-LG included a 1:1 mixture of Alcalase and Prozyme reacted for 10 h at a 1.0% enzyme concentration relative to substrate. The molecular weight of HWPH was <5 kDa, and leucine was the prominent free amino acid. Both in vitro and in vivo tests showed that digestibility and intestinal permeability were higher in HWPH than in WP. In BALB/c mice, as compared to WP, HWPH reduced allergic reactions by inducing elevated Type 1/Type 2 helper T cell ratio in the blood, splenocytes, and small intestine. Thus, HWPH may be utilized in a variety of low allergenicity products intended for infants, adults, and the elderly.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.5
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• pp.787-795
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• 2001

For the developing natural fisheries flavoring substances using crustacea, the flavor constituents of enzyme hydrolysates from shore swimming crab (crab) and spotted shrimp (shrimp) were investigated. In taste-active compounds of both enzyme hydrolysates, total free amino acid contents of crab and shrimp enzyme hydrolysates were 5,226.7 mg% and 8,757.3 mg%, respectively. The major amino acids were taurine, glutamic acid, proline, asparagine, glycine, alanine, valine, leucine, lysine anserine and arginine. As for ATP related compounds, AMP was the principal component and small amounts of IMP was detected in both enzyme hydrolysates. In the quarternary ammonium bases, betaine was the principal component (593.8mg%), and contents of TMAO and betaine in both samples were 60.7 mg% and 850.0 mg%, 124.1 mg% and 755.9 mg%, respectively. The major components were Na, K, P and Cl in inorganic ions. The major fatty acids of both sample were 14 : 0, 16 : 0, 16 : 1n7, 18 : 1n9, 20 : 5n3 and 22 : 6n3, and composition ration of n3 polyunsaturated fatty acids of were 27.8% and 28.5%, respectively. Total 99~109 volatile compounds were detected as a cooked odor of crab and shrimp enzyme hydrolysates by SDE apparatus/gas chromatography/mass spectrometry. The volatile flavor compounds identified from cooked crab enzyme hydrolysate were composed of 6 acids, 10 alcohols, 7 aldehydes, 11 ketones, 1 ester, 5 phenols, 4 benzenes, 22 hydrocarbons, 1 furan, 21 nitrogen containing compounds and 11 micellaneous compounds. And the volatile flavor compounds indentified from cooked shrimp enzyme hydrolysate were composed of 13 acids, 10 alcohols, 6 aldehydes, 10 ketones, 3 esters, 2 phenols, 5 benzenes, 36 hydrocarbons, 1 furan, 14 nitrogen containing compounds and 8 micellaneous compounds.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.17 no.1
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• pp.1-5
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• 2014

The diagnosis and treatment of cow's milk protein allergy (CMPA) is still a challenge. A systematic literature search was performed using Embase, Medline, The Cochrane Database of Systematic Reviews and Cochrane Central Register of Controlled Clinical Trials for the diagnosis and treatment of cow's milk allergy (CMA). Since none of the symptoms of CMPA is specific and since there is no sensitive diagnostic test (except a challenge test), the diagnosis of CMPA remains difficult. A "symptom-based score" is useful in children with symptoms involving different organ systems. The recommended dietary treatment is an extensive cow milk based hydrolysate. Amino acid based formula is recommended in the most severe cases. However, soy infant formula and hydrolysates from other protein sources (rice) are gaining popularity, as they taste better and are cheaper than the extensive cow's milk based hydrolysates. Recent meta-analyses confirmed the safety of soy and estimate that not more than 10-15% of CMPA-infants become allergic to soy. An accurate diagnosis of CMA is still difficult. The revival of soy and the development of rice hydrolysates challenge the extensive cow's milk based extensive hydrolysates as first option and amino acid formula.