• Microbiology and Biotechnology Letters
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• v.30 no.1
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• pp.39-45
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• 2002

It was found that the peptides originated from the hydrolysates of silk fibroin have in vitro immunostimulating effects in murine macrophage RAW264.7 cells. The stimulation effects on nitric oxide (NO) production resulted from treatments of acid or enzymatic hydrolysates were measured. The silk fibroin preparation isolated from cocoon was most efficiently digested by acid hydrolysis. Even though the sole treatment of acid hydrolysate stimulated the NO production in dose-dependent pattern, a part of its activity was found to be caused by the contaminated endotoxin, LPS. When each endotoxin-free hydrolysates obtained by filtering it through an ultrafiltration membrane of molecular weight (MW) cut-off 10,000 to eliminate LPS was used, the peptic hydrolysate with lowest degree of hydrolysis showed the highest activity. The fractions of peptic hydrolysate with MW ranges of 1,000∼10,000, 500∼1,000 and below 500 also showed a higher MW-higher activity correlation. From the analyses of amino acid composition of each hydrolysate, it was found that the contents of arginine, lysine, alanine and glycine residues affected the activity level of hydrolysate. The results of this study showed a possibility of utilizing fibroin as a source for immunostimulating (chemopreventive) functional peptides.

• Microbiology and Biotechnology Letters
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• v.36 no.1
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• pp.43-48
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• 2008

The present study investigated the effect of physiologically active polysaccharide (SP1) isolated from Salicornia herbacea on streptozotocin-induced diabetic rats. Male Spraque-Dawley rats were divided into four groups which were normal control group (NC), diabetic control group (DC), diabetic CSP group (DCSP), and diabetic SP1 group (DSP1). Animals were administrated with 2% experimental drinks for 6 weeks. The levels of glucose, triglyceride, total cholesterol, and high density lipoprotein (HDL)-cholesterol in the serum were measured before and after intake of test compounds. The levels of glucose and triglyceride in the DSP1 were significantly lower than those in the DC by 25% and 20%, respectively. The levels of total cholesterol and high density lipoprotein (HDL)-cholesterol in the DSP1 were similar to those in the DC. These results suggest that SP1 substantially exhibit anti-hyperglycemic and anti-hypertriglyceridemic activity in diabetic rats. Therefore SP1 is believed to show remarkable anti-diabetic effect on streptozotocin-induced diabetic rats.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.9
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• pp.989-994
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• 2005

The treatment efficiency and the degradation characteristics of humic acid were investigated in three processes-GAC adsorption, Ozone alone and Ozone/GAC hybrid process, in which $UV_{254}$, DOC, molecular size distribution and surface change of GAC were evaluated. DOC removal rate in Ozone/GAC hybrid profess(ca. 80%) was higher than the arithmetic sum of Ozone alone(38%) and GAC adsorption(19%). This result approves that the combined Ozone/GAC hybrid process brings synergistic effects on DOC removal from the HA containing water. $UV_{254}$ decrease rate was also at the highest in Ozone/GAC hybrid process from the three processes. It may be interpreted that the granular activated carbon in Ozone/GAC hybrid process acts as not only an adsorbent but also a catalyst for ozonation, and futhermore offers an additional reaction site between adsorbed organic matter and ozone. In the study of molecular sire distribution, there was no significant change of molecular size distribution in the GAC adsorption process during the reaction time of 120 min. In Ozone alone process, the fraction of molecular size over 30 kDa was decreased a little at the beginning and left constant after 10 min. But in Ozone/GAC hybrid process, the molecules size over 30 kDa of HA was significantly decreased from 36.3% to 3.9%. And also the fraction of smaller molecular size below 0.5 kDa was increased from 4.8%(untreated HA) to 12.3%(in Ozone alone) and 40.1%(in Ozone/GAC) respectively at the reaction time of 120 min.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.12
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• pp.1321-1326
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• 2005

As a results of this research, the Nakdong River consisted of 43% of hydrophobic fraction, 39% of hydrophilic fraction, and 18% of transphilic fraction. The hydrophobic fraction in this raw water was mostly fulvic acid. Fulvic acid comprised of 62% and the rest was humic acid(38%). There was more carboxylic acid functional roup(64%) than phenolic group(36%). HPI-N and HPI-C comprised of 17% and 22% in the hydrophilic portion, respectively. The results of the membrane fouling test using UF membrane according to NOM fractions. HPI-N caused more fouling than HPI-C. Humic acid caused more fouling than fulvic acid probably due to higher adsorption capacity. Since humic acid has higher adsorption capacity than fulvic acid, it would be more adsorbed onto the membrane pores. The carboxylic acid functional group caused more fouling than the phenolic group.

• Journal of the Korean Applied Science and Technology
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• v.34 no.3
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• pp.673-682
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• 2017

Protein hydrolysates derived from plants and animals having antioxidant, suppression of hypertension, immunodulatory, alleviation of pain, and antimicrobial activity has been known as playing important role like hormone. This study was fractioned to hydrolysis of Ogae egg white protein using the ultrafiltration. The antioxidant activity of the produced peptides was analyzed. As a result, the maximum value of DPPH radical scavenging was 1 kDa(70.83 %), hydroxy radical scavenging was 5 kDa(47.01 %), superoxide anion radical scavenging was 5 kDa(40.57 %), and $Fe^{2+}$ chelation ability was 5 kDa(29.87 %). Furthermore, the antioxidant Inhibition concentration ($IC_{50}$) of peptides was evaluated for each fraction. As a result, the maximum value of HDS was superoxide anion radical scavenging($IC_{50}$, 5.42 mg/ml). 1 kDa was $Fe^{2+}$ chelation ability($IC_{50}$, 1.67 mg/ml), 5 kDa was $Fe^{2+}$ cheating ability($IC_{50}$, 2.09 mg/ml), 10 kDa was $Fe^{2+}$ cheating ability($IC_{50}$, 2.61 mg/ml), papain was $Fe^{2+}$ cheating ability($IC_{50}$, 4.53 mg/ml). Therefore, we expect that peptides produced from Ogae egg white protein using 5 kDa fraction are useful as an antioxidant functional food ingredients.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.5
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• pp.787-791
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• 2012

Bloods from slaughtered Korean native cattle (Hanwoo : Bos taurus coreanae) can be used in agriculture with various beneficial effects on the environment. This study was performed to find out the effect of the application of calcium and germanium, which are chelated with peptides made of cattle bloods on the absorption of them by cherry tomato (Lycopersicon esculentum Mill.). Peptide was purified by enzymatic hydrolysis and ultrafiltration from serum protein, which is composed of Asp, Glu, Lue etc. Chelated Ca and Ge were produced by reacting the peptide with $CaCl_2$ and Ge-$132^{(R)}$. Then, they were applied to cherry tomato during cultivation period at the rate of $300mL{\times}3times$ (10 days interval) for each tomato tree. Application of chelated-Ca increased the Ca contents in leaves and fruits of cherry tomato showing as 19.9% and 23.4% in newerly prepared chelated-Ca-200 ($200mg\;L^{-1}$), 8.1% and 6.8% in commecrial Calciolid Ca-300 ($300mg\;L^{-1}$) compared to 3152.6 and $63.2mg\;kg^{-1}$ in control, respectively. Application of chelated-Ge showed the increase in the germanium contents in both leaves and fruits of cherry tomato by over 6 times than those of control and over 4 times than Ge $132^{(R)}$-20 application. As a result of this study, it seemed that the application of chelated-Ca and chelated-Ge would be more effective than the existing commertial one in the absorption of calcium and germanium by cherry tomato.

• Membrane Journal
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• v.9 no.3
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• pp.157-162
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• 1999

In the crosslining reaction of poly(vinyl alcohoJ)(PVA) with sulfur-succinic acid which had been established in our previous work, reaction temperature, 15$0^{\circ}C$, was so high to collapse the pore struc¬tures in support membrane for the preparation of composite membrane. Therefore, the efforts have been focused on lowering of the reaction temperature to 100$^{\circ}$C by using a catalysis, HC!. The newly established crosslinking reaction was characterized through the analysis of the chemical and thermal properties. From these results, the optimum conditions for the membrane preparation couId be drawn as followings : (i) reac¬tion temperature, 100 $^{\circ}C$,(ii) reaction time, 90 min, (iii) the concentration of the catalysis (HCD, 1.5%. Com¬posite membranes were fabricated by coating a casting solution containing PYA, sulfur-succinic acid and HCl on a support membrane followed by crosslinking it at 10$0^{\circ}C$. The resulting membranes were applied to the pervaporation separation of methyl-tert-butyl ether(MTBE)/methanol (MeOH) mixtures at 30, 40, and 5O$^{\circ}C$. The flux of 5.09 g/$m^2$hr at 5O$^{\circ}C$ and the highest separation factor of 1622 were obtained, respectively.

• Korean Journal of Agricultural Science
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• v.29 no.2
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• pp.78-90
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• 2002

This study was carried out to investigate whether peptide produced from wheat protein by enzyme hydrolysis can be used as a natural antimicrobial agent. Antimicrobial peptide was obtained from wheat protein by protease of 7 species. The produced antimicrobial peptide was purified through ultrafiltration, membrane filtration and HPLC, and molecular weight and amino acid sequence of the purified antimicrobial peptide were determined. Among hydrolysate produced from wheat protein by protease of 7 species, antimicrobial activity was observed for the peptide obtained from Asp. saito protease. The Asp. saito protease did production antimicrobial hydrolysate showing the highest antimicrobial activity at reaction condition of $37^{\circ}C$ and pH 6.0, but not at reaction condition above $50^{\circ}C$. Wheat protein hydrolysate was fractionated by membrane filtration and showed antimicrobial activity between molecular weight 1,000 - 3,000. The antimicrobial activity fraction obtained by membrane filtration was separated through HPLC and showed antimicrobial activity in the peak of retention time 31.1 - 31.8 min. Since after wheat protein protease hydrolysate was heated during 15 min at $121^{\circ}C$, antimicrobial activity was maintained, we could be conviction as heat-stable peptide. Molecular weight of antimicrobial peptide identified by MALDI-mass was 1,633. Amino acid sequence of antimicrobial peptide was cysteine, glycine, prolin, prolin, prolin, valine, valine, alanine, alanine and arginine.

• Korean Journal of Food Science and Technology
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• v.28 no.4
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• pp.684-688
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• 1996

In order to search for antithrombotic peptides from soybean paste, the inhibitory activity of water extract of soybean paste and its peptide fractions on ADP-induced aggregation of washed platelets was assayed. Soybean paste extract treated with ultrafiltration (M.W. cut off, 3,000 daltons) was found to have inhibitory activity of 90% at the dose of $96\;{\mu}g/ml$ by the method of turbidometric aggregometer. Soybean paste extract was fractionated to 19 fractions (No. B-18) by Dowex 50W X-2 ion exchange column chromatography and activity test was performed by the microplate method. All of the fractions had antithrombotic activity $(IC_{50},\;101,000\;{\mu}g/ml)$, and most fractions had higher activity than positive control, RGDS $(IC_{50}.\;205\;{\mu}g/ml)$. Especially, basic fractions No.16-18 showed higher activity than soybean paste extract $(IC_{50},\;30\;{\mu}g/ml)$. The fraction No.16 with the highest activity $(IC_{50},\;10\;{\mu}g/ml)$ was purified and analysed for amino acid composition. The results showed that histidine, arginine, and alanine were major residues in the peptide part of the fraction.

• Korean Journal of Food Science and Technology
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• v.38 no.4
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• pp.488-494
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• 2006

This study was carried out in order to investigate the feasibility of utilizing concentrated sunmul (soybean curd whey), which is a waste by-product of soybean curd processing, as a functional food ingredient. Sunmul Powder was concentrated by ultrafiltration and spray dried with or without dextrin. Oil adsorption capacity of UF retentate powder was similar to that of ISP (Isolated Soy Protein) and higher than that of sunmul powder, whereas water holding capacity of UF retentate powder was lower than that of ISP. Protein solubility of all types of UF retentate powder was significantly higher than that of ISP at pH 2.0-10.0 with the lowest protein solubility seen at pH 4.0 and solubility increasing as the conditions became more acidic or alkaline. Emulsifying activity indexes of UF retentate powder at pH 2.0-10.0 were not influenced by pH. Emulsion stability of 4% sunmul solution was lowest at pH 4.0, but that of UF retentate powder was higher at acidic pH values and decreased with increasing pH. Foaming capacities of sunmul and UF retentate powder were high at pH 4.0-6.0, but the foam of UF retentate powder disappeared within 20 minutes in all conditions of pH.