• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.496-496
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• 2003

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.11
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• pp.1587-1593
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• 2009

Duck egg white (DEW) hydrolysates were prepared by five enzymes (papain, trypsin, chymotrypsin, alcalase, and flavourzyme) and their antioxidant activities investigated in this study. DEW hydrolyzed with papain (DEWHP) had the highest peptide content among the five enzymatic treatments. Besides, the peptide content of DEWHP increased when the enzyme to substrate ratio (E/S ratio) increased. It was suggested that higher E/S ratio contributed to elevate the degree of hydrolysis of DEW effectively. Similar results were also obtained by Tricine-SDS-PAGE. In addition, SDS-PAGE patterns indicated papain was the only one amongst all enzymes with the ability to hydrolyze DEW. In antioxidant properties, DEWHP showed more than 70% of inhibitory activity on linoleic acid peroxidation and superoxide anion scavenging. Moreover, the $Fe^{2+}$ chelating effect of DEWHP was greater than 90%, while no significant difference was observed in DPPH radical scavenging and reducing ability. The results of peptide contents, antioxidant activities and electrophoresis suggested that the higher the peptide content, the stronger the antioxidant activities in DEWHP.

• 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 the Korean Society of Food Science and Nutrition
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• v.27 no.1
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• pp.93-101
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• 1998

In order to improve the functional properties of several fish meat extracts as an alternate protein source, theri basic plastein reactions were evaluated. The UV absorption at 270 and 290 nm indicated that plasteins had higher amount of hydrophobic peptide or amino acid than the fish meat extracts. The water solubilities of the extracts were reduced at acidic pH. Values for the emulsifying capacity of the extracts and plasteins were over 30% although the latter showed the higher ones than the former. The osmolalities of the extracts at 1.0% concentration were 39(loach), 33(bastard halibut), 30(jacopever) and 24(crucan carp) milliosmole. Generally the slightly higher osmolalities were noted in the plasteins to be compared with the extracts. Both the extracts and plasteins exhibited a higher antioxidative effect than tocopherol. The hydrophobic amino acid which had been introduced at plastein reaction attributed the stronger antionxidative effect of its product than the extracts.

• Preventive Nutrition and Food Science
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• v.13 no.3
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• pp.196-203
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• 2008

Hwangtae, dried Alaska pollack, is a major storage product in the fish processing industry. Hwangtae is prepared by removing the internal organs and drying outdoors during the cold witner months by allowing it to thaw during the daytime and re-freeze at night under sub-zero ($-10^{\circ}C$) conditions and gradually dry from December until the next April for around 5 months from Myungtae. In this study, ground Hwangtae was hydrolyzed using two proteolytic enzymes (pepsin and alcalase) which produced five soluble active peptides from Hwangtae (yellowish dried Pollack, Theragra chalcogramma) protein. Two different peptides with strong antioxidative activity were isolated from the hydrolysate using consecutive chromatographic methods of Sephadex G-25 gel, ion-exchange chromatography on a Sepharose-Sephadex C-25 gel, and high-performance liquid chromatography. The isolated peptides, APO1 and APO2, were composed of 16 and 13 amino acid residues, respectively. Both peptides contained a Gly residue at the C-terminus and the repeating motif Gly-Pro-Hyp. The peptide with a molecular weight less than 1,000 Daltons (APACE) obtained from enzymatic hydrolysates of Hwangtae exhibited the highest ACE inhibitory activity. The APACE peptides was composed of 4 amino acid residues (Gly-Leu-Leu-Pro). These results suggest that Hwangtae hydrolysates could be a good source of peptides with ACE inhibitory activity. Biochemical analysis indicated that two 70 kDa peptides (APG1 and APG2) isolated from the hydrolysate had gelatinoytic activity, which was shown to be a calcium dependent protease type as showed by gelatin SDS PAGE.

• Food Science of Animal Resources
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• v.37 no.5
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• pp.752-763
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• 2017

Marine fish skin peptides (FSP) have been widely studied due to their antioxidant and antimicrobial properties. We aimed to use a natural antioxidant, FSP, to replacing synthetic preservatives in a pork patty model, which is safer for human body. Moreover, nano-liposome technology can be applied for masking the fishy smell and improving the stability of this peptide. Therefore, in this study, the effects of FSP and FSP-loaded liposomes (FSPL) on pork patty were evaluated through the tests of thiobarbituric acid reactive substances (TBARS), color, cooking loss, texture, volatile basic nitrogen (VBN), and the pH value, during 14 d of refrigerated ($4^{\circ}C$) storage. The results showed that all FSP-treated patties had lower TBARS values than control patties, which indicated an inhibitory effect of FSP on lipid oxidation. This effect in the patties depended on the FSP concentration. However, FSPL-treated patties showed significantly higher and undesirable TBARS values compared to the control, and this effect depended on the FSPL concentration. None of the physicochemical results showed remarkable changes except the pH and VBN values. Therefore, this study provides evidence that FSP has great potential to inhibit the lipid oxidation of pork patties and is capable of maintaining the quality and extending the shelf life. However, it is necessary to study the application of FSP treatments greater than 3% to improve the antioxidant effect on pork patties and search for other coating materials and technology to reduce the drawbacks of FSP.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.8
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• pp.1124-1129
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• 2005

Functional activities of low molecular weight substances purified from pepsin hydrolysates of four different seaweeds; Costaria costata, Enteromorpha prolifera, Grateloupia filicina and Porphyra tenera, were inves-tigated. Each pepsin hydrolysate of Costaria costata, Enteromorpha prolifera, and Grateloupia filicina resulted in three peptide peaks on Bio-Rad P2 gel chromatography pattern, while that of Porphyra tenera showed 2 peaks. Peak 1 of Porphyra tenera showed the highest antioxidative activity followed by peak 2 of Porphyra tenera and peak 2 of Costaria costata in order Peak 1 of Porphyra tenera showed the highest ACE inhibitory activity followed by peak 3 and peak 2 of Enteromorpha prolifera in order. Peak 1 and peak 2 of Porphyra tenera, and peak 2 of Enteromorpha prolifera showed the highest antityrosinase activity followed by peak 3 of Enteromorpha prolifera. Peak 1 of Enteromorpha prolifera showed the highest antitumor activity followed by peak 2 of Costaria costata, peak 3 of Enteromorpha prolifera, and peak 3 of Grateloupia filicina in order. Porphyra tenera showed the highest functional activities, which is thought to be due to its high protein content. Structure and amino acid sequence of low molecular weight peptide of Porphyra tenera should be analyzed in the further study.

• Food Science of Animal Resources
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• v.44 no.3
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• pp.533-550
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• 2024

Peptides with bioactive effects are being researched for various purposes. However, there is a lack of overall research on pork-derived peptides. In this study, we reviewed the process of obtaining bioactive peptides, available analytical methods, and the study of bioactive peptides derived from pork. Pepsin and trypsin, two representative protein digestive enzymes in the body, are hydrolyzed by other cofactors to produce peptides. Bicinchoninic acid assay, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, chromatography, and in vitro digestion simulation systems are utilized to analyze bioactive peptides for protein digestibility and molecular weight distribution. Pork-derived peptides mainly exhibit antioxidant and antihypertensive activities. The antioxidant activity of bioactive peptides increases the accessibility of amino acid residues by disrupting the three-dimensional structure of proteins, affecting free radical scavenging, reactive oxygen species inactivation, and metal ion chelating. In addition, the antihypertensive activity decreases angiotensin II production by inhibiting angiotensin converting enzyme and suppresses blood pressure by blocking the AT1 receptor. Pork-derived bioactive peptides, primarily obtained using papain and pepsin, exhibit significant antioxidant and antihypertensive activities, with most having low molecular weights below 1 kDa. This study may aid in the future development of bioactive peptides and serve as a valuable reference for pork-derived peptides.

• Fisheries and Aquatic Sciences
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• v.12 no.4
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• pp.249-257
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• 2009

This study is conducted to partially purify an antioxidative peptide in a two-step gelatin hydrolysate from Alaska pollock surimi refiner discharge, which was obtained by sequential treatment with Pronase E and Flavourzyme. The two-step gelatin hydrolysate was fractionated using chromatographic methods. Based on the same protein concentration of each fraction, the antioxidative activities (85.1-95.4%) of positive fractions fractionated by ion-exchange chromatography were higher than those (27.2-87.8%) from gel filtration. Then, further purification of the positive fractions was performed. Among them, the partially purified A1C1L2G1 and A1C1L2G2 fractions showed 96.2% and 85.1% inhibition, respectively, of linoleic acid peroxidation. The A1C1L2G1 fraction was composed of 15 kinds of amino acids and the predominant amino acids were proline, glycine and alanine. The results obtained in this study suggested that the fraction partially purified through chromatographic methods from the two-step gelatin hydrolysate of Alaska pollock surimi refiner discharge could be useful as a supplementary source for improving health functionality.

• Korean Journal of Food Science and Technology
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• v.21 no.4
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• pp.492-497
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• 1989

The antioxidant effects against linoleic acid of various protein hydrolysates from fish protein, defatted soybean cake, egg albumin and casein were investigated. Each protein hydrolysate by enzyme hydrolysis exhibited the antioxidative effects by addition of 5mg and 10mg per 1g linoleic arid. Especially, egg albumin and fish protein hydrolysates had a great antioxidative effects. The protein hydrolysates indicated the synergitic effects with ${\alpha}-tocopherol$, and indicated scavenging effects toward metal ion $(Fe^{3+},\;Cu^{2+})$ as prooxidants.