• Journal of Dairy Science and Biotechnology
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• v.14 no.2
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• pp.135-146
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• 1996

This experiment was carried out to investigate the changes of casein of cheese base treated with substitute enzyme during ripening. The cheese base without enzyme treatment(control, D)and cheese base treated with only calf rennet(A), cheese base treated with mixed enzyme(calf rennet :porcine pepsin 1:1, B), cheese base treated with only porcine pepsin(C) were manufactured. The changes of casein were analyzed by means of HPLC and electrophoresis as experimental parameters during ripening. Gel filtration(HPLC) of casein by Superose 12 column in Cheddar cheese showed 5 fractions immediately after manufacturing and 8 fractions after six months ripening. Though D showed no difference in number of fraction(4 fraction) during 8 weeks ripening, A, B, C have represented the change of fraction number 4 to 5, 4 to 7, 4 to 8, respectively. As the mixing ratio of porcine pepsin increased, higher degradability of casein appeared. After 8 weeks ripening, electrophoresis of casein in cheese base showed three bands as an ${\alpha}$$_{s1}$casein from A and five bands from B, C. In case of D one major band and two minor bands were appeared as an ${\alpha}$$_{s1}$-casein. As the additional level of porcine pepsin increased the concentration of ${\beta}$-casein band decreased. however, that of ${\gamma}_1$ ${\gamma}_2$-casein band increased and para-${\kappa}$-casein band appeared from A, B, C, except D.

• Membrane Journal
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• v.19 no.3
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• pp.194-202
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• 2009

In this study periodic water-back-flushing using permeate water was performed to minimize membrane fouling and to enhance permeate flux in advanced water treatment by tubular ceramic ultrafiltration membrane for Gongji stream in Chuncheon city. The back-flushing period (FT, filtration time) 2 min with periodic water-back-flushing of 15 sec showed the highest value of dimensionless permeate flux (permeate flux vs. initial permeate flux), and the lowest value of resistance of membrane fouling. Also in the results of BT effect at fixed FT 10 min, BT (back-flushing time) 20 sec showed the lowest value of resistance of membrane fouling and the highest value of dimensionless permeate flux, and we could be obtained the highest total permeate volume of 107.3 L. Consequently FT 10 min and BT 20 sec could be the optimal condition in Gongji stream water treatment, which was the exactly same results of our previous tubular alumina microfiltration. Then the average rejection rates of pollutants by our tubular ceramic UF system were 97.0% for turbidity, 32.1 % for chemical oxygen demand by manganese method, 28.8% for ammoniac nitrogen and 54.4% for T-P.

• KSBB Journal
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• v.18 no.3
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• pp.180-185
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• 2003

Glycosaminoglycans (GAGS was extracted from sea squirt, Styela clava with sodium phosphate at 105$^{\circ}C$ for 2 hr and deproteinized with trichloroacetic acid or hydrochloride. The GAGs obtained from tunic consist 41.7% crude carbohydrates, 31.8% crude protein, and 31.2% sulfate. It was mainly constituted of galactose, glucosamine, glucose, mannose, and glacrosamine. The prominent amino acid were phenylalanine, threonine, glutamic acid, and aspartic acid. Mineral contents was mainly constituted 3.0 mg% sodium, 1.6 mg% potassium, and 1.2 mg% phosphorus. Trichloroacetic acid, hydrochloride and 5-sulfosalicylic acid were used for deprotein of the GAGs. Effective volume for deprotein of crude GAGs were 5.0% trichloroacetic acid (w/v) and 10.0% HCI (v/v) treatment. The deproteinized GAGs contained 35.1%, 35.4% of protein and 22.0%, 18.5% of sulfate, respectively.

• Membrane and Water Treatment
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• v.9 no.2
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• pp.69-77
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• 2018

The use of membrane as an innovative technology for water treatment process has now widely been accepted and adopted to replace the conventional water treatment process in increasing fresh water production for various domestic and industrial purposes. In this study, ultrafiltration (UF) membranes with different formulation were fabricated via phase inversion method. The membranes were fabricated by varying the polymer concentration (16 wt%, 18 wt%, 20 wt%, and 21 wt%). A series of tests, such as field emission scanning electron microscope (FESEM), pore size and porosity, contact angle, and zeta potential were performed to characterize the membranes. The membrane performance in terms of permeation flux and rejection were evaluated using a laboratory bench-scale test unit with mine water, lake water and tube well as model feed solution. Long hour filtration study of the membranes provides the information on its fouling property. Few pore blocking mechanism models were proposed to examine the behaviour of flux reduction and to estimate the fouling parameters based on different degree of fouling. 21 wt% PVDF membrane with smaller membrane pore size showed an excellent performance for surface water treatment in which the treated water complied with NWQS class II standard.

• Food Science of Animal Resources
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• v.22 no.1
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• pp.59-65
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• 2002

This study was carried out to evaluate the effect of whey protein concentrate-80%(WPC-80) and whey protein isolate(WPI) on the growth of B. bifidum Bb-11. Whey proteins($\alpha$-lactalbumin, $\beta$-lactoglobulin) were digested with trypsin, then their hydrolyzates were separated into three fractions (>10,000Da, 3,000∼10,000Da, <3,000Da) by two-step ultrafiltration process with Centriprep 10 and Centricon-30. These three fractions by molecular weight were evaluate growth-promoting effects for the B. bifidum Bb-11. The results obtained were summarized as follows; The growth rate of B. bifidum Bb-11 tended to increase by supplementation of WPC-80 to basal medium, but decreased by supplementation of WPI. Two whey proteins were hydrolyzed by trypsin at 40$\^{C}$ for 6 hrs, and three fractions were collected by UF treatment and concentrated by Centricon-30. Collected concentrations of protein of F-I and F-II and F-III from $\alpha$-lactalbumin were 11.53mg, 7.79mg, and 5.21 mg and those of protein from $\beta$-lactoglobulin were 4.13mg, 5.30mg, and 9.351mg, respectively. Three fractions of $\alpha$-lactalbumin hydrolyzates promoted the growth rate of B. dbifidum Bb-11. Growth promoting activities of hydrolyzates(F-I and F-II) with molecular weight below 10,000Da were stronger than that of hydrolyzate(F-III) above 10,000Da. However, there was no significant difference between the hydrolyzate F-I and F-II. Three fractions of $\beta$-lactoglobulin hydrolyzates improves the growth rate of B.bifidum Bb-ll. The growth of B.bifidum Bb-ll was decreased after 24 hr incubation by supplementation of either F-II or F-III fraction compared to basal Whey medium, but maintained the enhancement by supplementation of F-I.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.3
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• pp.257-264
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• 2006

This study investigated the effects of hybrid process(chemical coagulation, Fenton oxidation and ceramic UF(ultrafiltration)) on COD and color removals of commercial reactive dyestuffs. In the case of chemical coagulation, the optimal concentrations of $Fe^{3+}$ coagulant for COD and color removals of RB49(reactive blue 49) and RY84(reactive yellow 84) were determined according to the different coagulant dose at the optimal pH. They were 2.78 mM(pH 7) in RB49 and 1.85 mM(pH 6) in RY84, respectively. In the case of Fenton oxidation, the optimal concentrations of $Fe^{3+}\;and\;H_2O_2$ were obtained. Optimal $[Fe^{2+}]:[H_2O_2]$ molar ratio of COD and color removals of RB49 and RY84 were 4.41:5.73 mM and 1.15:0.81 mM, respectively. In the case of ceramic UF, the flux and rejection of supernatant after Fenton oxidation were investigated. After ceramic UF for 9 hr, the average flux of RB49 and RY84 solutions were $53.4L/m^2hr\;and\;67.4L/m^2hr$ at 1 bar, respectively. In addition, the permeate flux increased and the average flux recovery were 98.5-99.9%(RB49) and 91.0-97.3%(RY84) according to adopting off-line cleaning(5% $H_2SO_4$). Finally, COD and color removals were 91.6-95.7% and 99.8% by hybrid process, respectively.

• Food Science of Animal Resources
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• v.32 no.5
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• pp.652-658
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• 2012

This study was carried out to identify the ACE (Angiotensin converting enzyme) inhibitory activity of casein hydrolysates for development of anti-hypertensive hydrolysates. Sodium caseinate was treated with six kinds of commercial proteases such as Flavourzyme, Protamex, Neutrase 1.5, Alcalase, Protease M, and Protease S for 8 h individually, and was then treated with the enzyme combination for 4 h at $45^{\circ}C$. The hydrolysate which had the highest ACE inhibitory effect was then hydrolysed successively with three digestive enzymes: pepsin, trypsin, and ${\alpha}$-chymotrypsin, at $37^{\circ}C$ for 4 h under conditions mimicking those of the gastrointestinal tract. UF (ultra filtration) treatment was applied to one of the secondary hydrolysates to determine ACE inhibitory activity. When sodium caseinate was hydrolysed by commercial proteases, the degree of hydrolysis (DH) showed 2.54 to 4.25% and after secondary hydrolysis, DH showed 4.30 to 5.22%. ACE inhibitory activity and $IC_{50}$ values decreased, and inhibition rates increased during hydrolysis. Protamex treatment showed the lowest $IC_{50}$ value ($516{\mu}g/mL$) and Flavourzyme hydrolysate showed the highest $IC_{50}$value ($866{\mu}g/mL$). As the first hydrolysate was treated with Flavourzyme, the ACE inhibitory activity increased. Neutrase hydrolysate had the highest activity with an $IC_{50}$ value ($282{\mu}g/mL$). When Neutrase plus Flavourzyme treatment was hydrolyzed by digestive enzymes, the $IC_{50}$ value ($597{\mu}g/mL$) was decreased statistically (p<0.05). As Neutrase plus Flavourzyme hydrolysate is treated by UF with MW cut-off 10,000, permeate showed $273{\mu}g/mL$ of $IC_{50}$ value, showed no difference, but retentate which has over MW 10,000 showed statistically different $IC_{50}$ value, $635{\mu}g/mL$ (p<0.05).

• Journal of Life Science
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• v.15 no.1 s.68
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• pp.9-14
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• 2005

Batch enzymatic hydrolysis of egg yolk protein by protease was carried out at laboratory scale coupled to an ultrafiltration module. Effect of ethanol concentrations on the performance of enzymatic hydrolysis was studied to determine the optimum condition of recovery of hydrolysate. The enzymatic hydrolysis was conducted stepwise with following conditions, $50^{\circ}C$, pH 10.0 and pH 6.5. Ethanol concentration was changed from 10 to $40\%$ (w/w). As ethanol concentration was increased, the recovery yield of total solid and protein in enzymatic hydrolysate was also increased. The content of sialic acid and protein in hydrolysate was independent of ethanol concentration. We also investigated the effect of ethanol concentration on the performance of ultrafiltration. As the concentration of ethanol in yolk protein was increased, the recovery yield of product was increased. Ultra­filtration of egg yolk protein hydrolysate was conducted to increase the content of sialic acid. Four ultrafiltation modules were used in this study, and we evaluated the performance of the UF modules. When Amicon module was used, the recovery percentage of total solid in retentate was $6.0\%$, which is the highest among the modules used. In spite of the difference in the recovery yield of total solid, the purity of sialic acid in retentate was about $2.0\%$, which was 5 times higher than that in feed. It was concluded that the recovery yield and the purity of sialic acid did not correlate with the types of modules and the size of MWCO.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.10
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• pp.1046-1054
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• 2006

The raw water DOC contained 39.3% of hydrophilics, 42.9% of hydriophobic, and 17.8% of transphilic. 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 group(64%) than phenolic group(36%). HPI-N and HPI-C comprised of 17% and 22% in the hydrophilic portion, respectively. The fouling mechanisms on the membrane surface and into its porous structure were analyzed in terms of several kinetic models. In order to analyze the fouling kinetics, the various kinetic models described in this paper were used to fit the experimental results. The kinetic models and kinetic constants obtained for each operation condition. The permeate flux was rapidly declined by simultaneous pore blocking and cake formation. Also, the permeate flux declined with decreasing internal pore size resulted from organic deposition into the membrane pore. 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.

• Journal of Animal Environmental Science
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• v.14 no.2
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• pp.119-128
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• 2008

This experiment was conducted to investigate the effects of concentrated pig slurry using membrane filter on growth of tomato in nutriculture. Pig slurry was filtered by ultra filtration and concentrated by reverse osmosis process. Filtration of pig slurry was necessary to prevent the hose clogging in nutriculture. The concentrated pig slurry (CS) and nutrient solution (NS) were mixed by six different mixing ratios of 0:100, 20:80, 40:60, 60:40%, 80: 20 and 100%:0% based on nitrogen content. The chemical nutrient solution was the solution of National Horticulture Research Station for the growth of tomato. The concentration of nutrient solution was adjusted a range of $1.6{\sim}2.0mS/cm$ in EC. The plant height of tomato treated with CS 20+NS 80% was similar with NS 100% control plot. Plant height was highest in the plot of CS 20+NS 80%. The treatment of 100% concentrated pig slurry was lowest in the gowth characteristics of tomato. Number of cluster was very lower in 100% concentrated pig slurry compared with plot of chemical nutrient solution. In the beginning of growth stage, SPAD reading value was reduced in plot treated with CS 100%, but CS 20+NS 80% plot was higher compared to 100% concentrated pig slurry. SPAD value of tomato leaves was decreased as the amount of CS was increased. The SPAD value also in treatment of concentrated pig slurry was lower in the middle growth stage compared to control plot. The dry weight of stem and leaf were 107.4, 104.2g in plot of NS 100% and CS 20%+NS 80%, respectively. The fruit number and weight were decreased at high application plots of concentrated pig slurry, The fruit setting of tomato showed lowest in the plot treated with 100% concentrated pig slurry, and the growth of tomato severely decreased after application of 100% CS treatment. In conclusion, the growth characteristics such as plant height and fruit weight of tomato were not significantly different between the plots treated with mixture of 20% CS +80%NS and 100% nutrient solution treatment. In conclusion, the mixture solution of 20% of concentrated pig slurry and 80% of nutrient solution could be used as a nutrition solution of tomato nuticulture.