• The Korean Journal of Food And Nutrition
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• v.18 no.1
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• pp.11-18
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• 2005

Angiotensin Ⅰ converting enzyme(ACE) inhibitory activities of laver(Porphyra tenera) protein hydrolysates were investigated by enzymes used for hydrolysis, molecular fractions and drying methods. For the enzymatic hydrolysis, crude laver protein, separated by filtration of water extract of dried laver extracted with 20 times(w/v) water for 3 hours at boiling temperature, were hydrolyzed with three commercial protease, Pepsin, alcalase and maxazyme NNP at optimal conditions. The yield of hydrolysis and ACE inhibitory activities of which were high in order of pepsin, alcalase and maxazyme NNP. ACE inhibitory activities of laver hydrolysates by molecular levels were high in order of 3 kDa > 10 kDa > 3∼10 kDa, and the IC/sub 50/ ACE inhibitory activities by molecular lebels were 4 mg/mL(3 kDa), 5 mg/mL(total hydrolysate), and 20 mg/mL(10 kDa), respectively. The storage stability of dried laver hydrolysates at 20℃ were strongly affected by drying methods, hot air dried of which were much stabler than freeze-dried one.

• Korean Journal of Agricultural Science
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• v.39 no.4
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• pp.561-568
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• 2012

The aim of this study was to introduce a simple method for isolation of ${\alpha}$-lactalbumin, ${\beta}$-lactoglobulin and bovine serum albumin from cow's milk, and peptides produced by enzymatic hydrolysis of ${\alpha}$-lactalbumin, ${\beta}$-lactoglobulin and bovine serum albumin with alcalase. Whey protein were precipitated from whey by ammonium sulfate and, ${\alpha}$-lactalbumin and ${\beta}$-lactoglobulin were isolated using Hi Prep 26/60 Sephacryl S-100 column gel filtration chromatography. Bovine serum albumin and ${\beta}$-lactoglobulin were isolated by Mono-Q 5/50 GL column anion exchange chromatography of the 50% Ammonium Sulfate-supernatant. Isolated whey proteins were hydrolyzed by proteolytic alcalase. Tricine SDS-PAGE and reverse-phase HPLC analyses revealed that almost hydrolyzed all the ${\alpha}$-lactalbumin, ${\beta}$-lactoglobulin and bovine serum albumin with alcalase. Molecular weight of various peptides derived from alcalase hydrolysate were small molecular weight than 3.5 kDa.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.11
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• pp.1645-1652
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• 2015

We investigated the anti-wrinkle efficacy of hydrolysate from oyster protein by Protamex and Neutrase for the purpose of finding materials to assist skin health originating from marine organisms. There were about 7.9% free amino acids in the oyster hydrolysate, and contents of urea, taurine, alanine, and glycine were high. Oyster hydrolysate also showed collagenase inhibitory activity and was not toxic to CCD986sk human fibroblast cells. Yield of the fractions according to the molecular weight of oyster hydrolysate was 40% for less than 1,000 Da and 60.4% for less than 5,000 Da, respectively. Antioxidative effect, procollagen production, and matrix metalloproteinase-1 inhibitory activity were highest in 1,000~3,000 Da fractions. We observed that oyster hydrolysate and its less than 5,000 Da fraction are potential functional compounds for skin health and for improving wrinkles.

• International Journal of Industrial Entomology and Biomaterials
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• v.2 no.1
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• pp.7-13
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• 2001

Enzymatic hydrolysis of different forms of silk fibroin (soluble, gel and insoluble forms) by industrial and commercial enzyme preparations to obtain aqueous and powdered silk fibroin in relatively mild conditions was investigated. A mono-enzymatic hydrolysate systems were tested for hydrolysis of water-soluble form of fibroin as most productive form of protein substrate. Insoluble forms of substrate usually were hydrolyzed less effective. In some cases from soluble fibroin substrate gel was formed during hydrolysis process. This hindered intermixing and decreased rates of hydrolysis. Insoluble sediments were formed in enzymatic hydrolysates in other cases. These sediments and also sediment after chemical hydrolysis were purified and tested on amino acids content for comparison. Sediments formation in these conditions are considered as pure tyrosine isolation method. Obtained hydrolysates were characterized by gel-chromatography analysis and other standard biochemical methods. Possibility of application of enzymatic hydrolysis for preparation of silk fibroin hydrolysates is discussed.

• KSBB Journal
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• v.28 no.3
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• pp.151-156
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• 2013

${\beta}$-Glucan type oligomers which have angiotensin I converting enzyme (ACE) inhibitory activity were isolated and characterized from Capsosiphon fulvescens. After C. fulvescens was hydrolysis with Alcalase at $50^{\circ}C$, supernatant was harvested and separated with ultrafiltration membrane (MWCO 2 kDa). Oligomers which were less than 2 kDa of molecular weight were harvested for characterization. The nutrient composition of Alcalase hydrolysate was 89.9% carbohydrate, 4.2% protein and 5.9% sulfate. After ultrafiltration, the nutrient composition of oligomers was changed to 99.88% carbohydrate, 0.07% protein and 0.05% sulfate. The carbohydrate composition of oligomer was glucose (97.2%) and mannose (1.5%). The ACE inhibitory activities of Alcalase hydrolysate and oligomer were 72.1% and 82%, respectively. The molecular weight of oligomer was about 1 kDa. The oligomer was analyzed with FT-IR, $^1H$-NMR and methylation. The oligomers were ${\beta}$-1,3-glucans with ${\beta}$-(1,3)-linked glucose units.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.4
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• pp.445-453
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• 2016

Seahorse Hippocampus abdominalis a marine teleost fish, has long been used as one of the essential materials in traditional Chinese medicine. However, the uses of seahorse have been limited due to its high cost, despite its beneficial biological activities. Seahorse has not been widely explored for its biofunctional properties and active components. In the present study, the enzymatic hydrolysates of seahorse were prepared by using two digestive enzymes (trypsin and pepsin) and five food grade enzymes (neutrase, protamex, alcalase, kojizyme, and flavourzyme). The enzymatic hydrolysates indicated higher hydrolysis yields than its water extract. Among them, the distilled water-pepsin hydrolysate (DP) which was obtained by distilled water extraction followed by pepsin hydrolysis, showed the highest yield and protein content as well as the highest alkyl radical scavenging activity. Also, it provided protective effects against oxidative stress induced by AAPH in vero cell and zebrafish. Further fractionation based on the molecular weight was carried out to identify it’s active components, and < 5 kDa (less than 5 kDa) molecular weight fraction was confirmed to have the highest antioxidant activity. In conclusion, this study suggests that DP of seahorse has antioxidant properties, and might be a novel and useful material from the marine origin for healthy functional foods and cosmetics.

• Food Science of Animal Resources
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• v.29 no.5
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• pp.633-639
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• 2009

The principal objective of the current study was to prepare low molecular weight peptides from milk proteins using enzymatic hydrolysis techniques, in an effort to assess the antioxidant activity of these peptides. The casein and whey proteins isolated from fresh milk were treated with several proteolytic enzymes, such as chymotrypsin, pepsin, and trypsin and the resulting low molecular weight peptides were collected by TCA precipitation. Their identity was confirmed by SDS-PAGE analysis. The hydrolysis experiments indicated that whey protein treated with chymotrypsin displayed the highest degree of protein hydrolysis. The antioxidant activity of milk protein hydrolysates was determined by measuring the ABTS-radical scavenging activity. The results of these experiments showed that hydrolysis of the milk protein was effective in increasing their antioxidant activities. Especially, the tryptic digested casein displayed the highest radical scavenging activity (80.7%). The hydrolyzed low molecular weight milk protein was isolated using an ultrafiltration membrane. The casein hydrolysate passed through a membrane with molecular weight cut-off (MWCO) of 3 kDa displayed the strongest antioxidant activity.

• 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.

• Korean Journal of Food Science and Technology
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• v.51 no.5
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• pp.473-479
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• 2019

Gryllus bimaculatus (GB) has recently been registered as a food variety in Korea. In the present study, we prepared protein hydrolysates from GB and evaluated their antioxidant capacity. Protein hydrolysates were prepared from dried GB using enzymatic hydrolysis using five different proteases, and protein hydrolysates showing high hydrolysis value (alcalase, flavourzyme, and neutrase) were separated further into fractions ${\leq}3kDa$ and then lyophilized. Based on $RC_{50}$ values of hydrolysates (${\leq}3kDa$) obtained from four different antioxidant analyses, the flavourzyme hydrolysates showed relatively high levels of antioxidant capacity among the three hydrolysates, and in particular, it showed considerably strong antioxidant activity in 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays. The flavourzyme hydrolysate also significantly inhibited peroxidation of linoleic acid. These results suggest that protein hydrolysates from GB represent potential sources of natural antioxidants. Our current studies are focused on identification of active peptides from the flavourzyme hydrolysate.

• Journal of Animal Science and Technology
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• v.49 no.1
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• pp.129-136
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• 2007

This study was performed to determine the protein profiles using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Angiotensin-I-converting enzyme(ACE) inhibitory activity (IC50) as affected by the various meat cuts, digestion times with pepsin. Hydrolysates having the protein concentration of 10 ug/mL had approximately 36∼39% ACE inhibitory activities, regardless of meat cut and digestion time. Protein concentration and ACE inhibitory activity of the diluted hydrolysate increased after 1-hr digestion. In original hydrolysates, ACE inhibitory activities of loin had higher than those of round (P<0.05). In addition, non-heated hydrolysates had higher ACE inhibitory activities than heated counterparts. When myosin B was digested by pepsin more than 1 hr, improved ACE inhibitory activities were observed as compared to the non-digested control.