• Journal of Nutrition and Health
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• v.27 no.7
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• pp.699-708
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• 1994

This study aimed to verify the nutritional and curative effects of protein hydrolysate in rats with cysteamine-induced duodenal uncer. Duodenal ulcer rat model was established by intraperitoneal injections of cysteamine. Sprague-Dawley, female rats weighing approximately 200g were intraperitoneally injected twice cysteamine(13mg/100g BW) at intervals of 3h per day. This procedure was repeated 3$\times$at intervals of 3d. Animals fed on 10% casein diet for infection periods. After last injection, 4 kinds of diets(10% casein, 20% casein, 10% casein hydrolysate, 20% casein hydrolysate) were given. Gastric montility, trypsin activity in gastrointestinal content, retention rate of nitrogen, plasma total protein, albumin, amino-N, urinary urea nitrogen, creatinine and hydroxyproline were analyzed for nutritional effects of dietary nitrogen levels(10%, 20%) and sources(casein, casein hydrolysate). In duodenal ulcer rat model, there was no differences between 20% casein diet and 20% casein hydrolysate in the view of severeness of ulcer, gastric emptying rate, serum total protein, serum albumin, plasma $\alpha$-amino-N, UUN, creatinine excretion, GFR, nitrogen retention. On the other hand, rats on 10% casein hydrolysate diet group had more curative effect of the ulcer, higher plasma albumin concentration and nitrogen retention than 10% casein diet group. The casein hydrolysate diet group was lower trypsin activity in small intestinal content than the casein diet group, at both nitrogen levels(10%, 20%). The results suggest that protein hydrolysate be applied in diet therapy for the patients with gastrointestinal ulcer.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.6
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• pp.1147-1151
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• 1997

To develop an onion sauce, reaction conditions of celluclast 1.5L and pectinex on onion were investigated and organoleptic evaluations were carried out. Degree of hydrolysis(D.H) of hydrolysate by a mixture of celluclast 1.5L and pectinex was a higher than that by each enzyme. Hydrolysate by a mixture of celluclast 1.5L and pectinex(1:3v/v) showed 86% of D.H. and total sugar content of the hydrolysate was 54mg/ml. Hydrolysates showed 83~86% of D.H. at reaction temperature of $25^{\circ}C$ to 45$^{\circ}C$. Total sugar content of the hydrolysate was increased with increasing temperature. D.H. and total sugar content of hydrolysate was 76~86% and 51~63mg/ml, respectively, under acidic conditions. D.H. and total sugar content of hydrolysate were also increased with increasing time. Bitterness, sweetness and ordor of roasted pork prepared by adding onion and onion hydrolysate were significantly different(p<0.05), but color and preference between two groups were not significantly different(p<0.05) between two groups. There was no significant difference(p<0.05) in sweetness and bitterness of the roasted pork prepared by adding different amounts of onion hydrolysate, although ordor and preference of the roasted pork were significantly different(p<0.05).

• The Korean Journal of Food And Nutrition
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• v.9 no.2
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• pp.167-175
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• 1996

This studies were conducted to select optimal enzyme that produced hydrolysate from soybean, and to evaluated functionality of hydrolysate. Soybean powder was suspended with water and hydrolyzed by seven commercial proteases. Hydrolysate produced with protease from Bacillus subtilis showed the highest inhibition effect on the activity of angiotension converting enzyme(ACE), and the condition of enzymatic hydrolysis was 5cA substrate concentration, 0. l% enzyme concentration, 4 hour hydrolysis time. Under above optimum condition, soybean was hydrolyzed with protease from Bacillus subtilis yielding a DH (degree of hydrolysis) of about 49%. Hyrophobicity of hydrolysate was not correlated with the inhibition effect on ACE activity. The functionality of hydrolysate was significantly influenced by pH. Solubility of hydrolysate at alkali solution was greater than that at acidic solution.

• Journal of Microbiology and Biotechnology
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• v.3 no.4
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• pp.298-302
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• 1993

Pullulan was produced from starch hydrolysate with Aureobasidium pullulans SH8646. We could measure the correct amount of pullulan produced without the interference of starch from the culture supernatant by using a bacterial $\alpha$-amylase treatment and ethanol: acetone (1:1) precipitation. When 5% acid-hydrolyzed starch was used as a carbon source, the dry cell weights obtained were similar irrespective of DE values of starch hydrolysates. The dry cell weights of those on the starch hydrolysate media prepared with 0.1 N HC1 treatment, were slightly higher (9.5~10.5 g/l) than those on the starch hydrolysate media prepared with 1.0 N HCl (8.5~9.5 g/l). And among the starch hydrolysates showing DE values lower than 50, maximum pullulan production of 15 g/l was obtained at DE 30~40 starch hydrolysate but those showing DE values higher than 50, the pullulan production was increased with the increase of the DE value of starch hydrolysates. From the media containing 5%, 10%, and 15% starch hydrolysate (DE 25, 45, and 75), about 20~34% pullulan yield was obtained and the maximum pullulan yield of 34% (17g/l) was obtained from 5% DE 75 starch hydrolysate. The pullulan yields from starch hydrolysate media were much lower than those from glucose, maltose, maltotriose, and sucrose media.

• Korean Journal of Pharmacognosy
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• v.33 no.4 s.131
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• pp.312-318
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• 2002

Effect of the acid hydrolysate of silk fibroin on obesity was investigated in obese(057BL/KsJ-db/db) mice. After 8 weeks feeding of 1%(w/w) or 3%(w/w) fibroin hydrolysate, the extents of reduction in body weight were significantly higher than that of obese control. The weight reduction in female mice was higher than that in male mice. Plasma leptin in male mice increased up to 1.8-fold higher level than obese control by feeding hydrolysate. In case of female mice, however, it rather decreased with increased feeding concentration of hydrolysate. From the results of high glycine and serine contents of peptide fractions contained in fibroin hydrolysate, it was inferred that fibroin peptides might affect xylosyltransferase(XT) activity on chondroitin sulfate synthesis causing to change susceptibility of adipocytes to hormones such as insulin followed by the reduced leptin synthesis in female mice. The result of the higher lipolysis in hydrolysate-fed group than obese control indicated that the reduction in body weight was due to the increased lipolytic activities in male and female mice in common.

• Mycobiology
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• v.37 no.2
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• pp.133-140
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• 2009

To optimally convert corn hull, a byproduct from corn processing, into bioethanol using Pachysolen tannophlius, we investigated the optimal conditions for hydrolysis and removal of toxic substances in the hydrolysate via activated carbon treatment as well as the effects of this detoxification process on the kinetic parameters of bioethanol production. Maximum monosaccharide concentrations were obtained in hydrolysates in which 20 g of corn hull was hydrolyzed in 4% (v/v) $H_2SO_4$. Activated carbon treatment removed 92.3% of phenolic compounds from the hydrolysate. When untreated hydrolysate was used, the monosaccharides were not completely consumed, even at 480 h of culture. When activated carbon.treated hydrolysate was used, the monosaccharides were mostly consumed at 192 h of culture. In particular, when activated carbon-treated hydrolysate was used, bioethanol productivity (P) and specific bioethanol production rate ($Q_p$) were 2.4 times and 3.4 times greater, respectively, compared to untreated hydrolysate. This was due to sustained bioethanol production during the period of xylose/arabinose utilization, which occurred only when activated carbon-treated hydrolysate was used.

• Journal of Marine Bioscience and Biotechnology
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• v.14 no.1
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• pp.9-24
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• 2022

Low-molecular weight peptides derived from fish collagen exhibit several bioactivities, including antioxidant, antiwrinkle, antimicrobial, antidiabetic, and antihypertension effects. These peptides are also involved in triglyceride suppression and memory improvement. This study aimed to investigate the optimal processing condition for preparing low-molecular weight peptides from flounder skin, and the properties of the hydrolysate. The optimal processing conditions for peptic hydrolysis were as follows: a ratio of pepsin to dried skin powder of 2% (w/w), pH of 2.0, and a temperature of 50℃. Peptic hydrolysate contains several low-molecular weight peptides below 300 Da. Gly-Pro-Hyp(GPHyp) peptide, a process control index, was detected only in peptic hydrolysate on matrix-assisted laser desorption/ionization-time-of-flight(MALDI-TOF) spectrum. 2,2'-azinobis-(3-3-ethylbenzothiazolline-6- sulfonic acid(ABTS) radical scavenging activity of the peptic hydrolysate was comparable to that of 1 mM ascorbic acid, which was used as a positive control at pH 5.5, whereas collagenase inhibition was five times higher with the peptic hydrolysate than with 1 mM ascorbic acid at pH 7.5. However, the tyrosinase inhibition ability of the peptic hydrolysate was lower than that of arbutin, which was used as a positive control. The antibacterial effect of the peptic hydrolysate against Propionibacterium acne was not observed. These results suggest that the peptic hydrolysate derived from a flounder skin is a promising antiwrinkle agent that can be used in various food and cosmetic products to prevent wrinkles caused by ultraviolet radiations.

• Journal of Life Science
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• v.10 no.5
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• pp.475-483
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• 2000

Normally, aerobic cells are protected from the damage of free radicals by antioxidative enzymes such as catalase, superoxide dismutase (SOD), glutathione (GSH) peroxidase and GSH-S-transferase. In this study, we have investigate the effect of egg yolk protein hydrolysates on antioxidative activity and the activity of antioxidative enzyme in cultured hepatocytes (Chang). Without the pretreatment with hydrolysate, about 50% of the hepatocytes were killed within 2h by 225$\mu$M tert-butyl hydroperoxide (t-BHP). By contrast, fewer than 20% of the 5 K hydrolysate (permeate from 5 kDa membrane and not passed through 1 kDa membrane)-pretreated hepatocytes were killed by the same concentrations of t-BHP. In addition, the activities of catalase, GSH peroxidase and GSH-transferase were significantly increasing with the treatment of 5 K hydrolysate. These results suggest that 5 K hydrolysate exerts antioxidative effect by increasing activity of antioxidative enzymes.

• Journal of Life Science
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• v.10 no.2
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• pp.131-139
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• 2000

Lecithin-free egg yolk protein (EYP), the by-product of lecithin extraction from egg yolk, which is denatured with an organic solvent, would normally be discarded. In this study, the denatured protein was renatured with alkali, and hydrolyzed with Alcalase in order to utilize by-product. The hydrolysate was separated through a series of ultrafiltration membranes with molecular weight cut-off (MWOO) of 10, 5 and 1 kDa, and the antioxidative activities of the hydrolysates was investigated. The 5K hydrolysate, permeate from 5 kDa membrane, showed stronger antioxidative activity than 10 K and 1 K hydrolysate which were permeated from 10 kDa and 1 kDa membrane, in a linoleic acid autoxidation system. In addition, the optimum concentration of antioxidative activity for 5 K hydrolysate was 1%, and the activity was about 37% higher as compared with α-tocopherol. The synergistic effect was also increased by using the hydrolysates with α-tocopherol.

• Journal of Microbiology and Biotechnology
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• v.27 no.1
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• pp.26-35
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• 2017

The hydrolysis of proteins constitutes an invaluable tool, granting access to a variety of peptide fragments with potentially interesting biological properties. Therefore, a hemoglobin (Hb) hydrolysate of Crocodylus siamensis was generated by digestion under acidic conditions. The antibacterial and antioxidant activities of the Hb hydrolysate were assessed in comparison with intact Hb. A disc diffusion assay revealed that the Hb hydrolysate exhibited antibacterial activity against eight strains of gram-positive bacteria and showed a higher efficacy than intact Hb. Moreover, the antioxidant activity of intact Hb and its hydrolysate was evaluated using ABTS and DPPH radical scavenging assays. The Hb hydrolysate exhibited free radical scavenging rates of 6-32%, whereas intact Hb showed a slightly higher activity. In addition, non-toxicity to human erythrocytes was observed after treatment with quantities of Hb hydrolysate up to $10{\mu}g$. Moreover, active fragmented Hb (P3) was obtained after purifying the Hb hydrolysate by reversed-phase HPLC. Scanning electron microscopy demonstrated the induction of bacterial cell membrane abnormalities after exposure to P3. Antibacterial and antioxidant activities play crucial roles for supporting the wound healing activity. Consequently, an in vivo mice excisional skin wound healing assay was carried out to investigate the effects of intact Hb treatment on wound healing in more detail. The results clearly demonstrate that intact Hb is capable of promoting 75% wound closure within 6 days. These findings imply that intact Hb of C. siamensis and its acid hydrolysate may serve as valuable precursors for food supplementary products benefitting human health.