• KSBB Journal
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• v.14 no.6
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• pp.696-701
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• 1999

The enzymatic hydrolysis of Castor oil for the mass production of ricinoleic acid was studied to find out the optimum conditions such as solvents and the weight ratio of substrate to enzyme. Three different lipases were tested for the hydrolysis of castor oil: lipase from Porcine Pancrease(lipsase PP), lipase from Candida cylindracea(lipase CC), lipase from Candida Rugosa(lipase CR). The poor mass transfer in water caused a low degree of hydrolysis of castor oil. To overcome this problem, organic solvents were used. Among organic solvents tested, hydrophobic solvents gave better results of hydrolysis than hydrophilic solvents. Organic solvents also lowered or changed the effect of pH. Isopropyl ether made complete hydrolysis of castor oil. The ratio of water to isopropyl ether and the ratio of weight ratio of lipase to castor oil were important for the hydrolysis of castor oil. At 30$^{\circ}C$ castor oil was completely hydrolyzed by 4 wt% of lipase in the mixture of isopropyl ether and water(1:1 in volume).

• Korean Journal of Pharmacognosy
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• v.7 no.2
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• pp.85-93
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• 1976

Since cellulose is the only organic material that is annually replenishable in very large quantities, we must explore ways to utilize it as a source of energy, food and chemicals. For the utilization of this resource, it is first enzymatic hydrolyzed to glucose, then the glucose can be used as a food, converted single cell protein by microorganism, fermented to clean burning fuel and other chemicals. Cellulolytic enzyme, cellulase, consists of two or three major components, $C_1-cellulase$, $C_x-cellulase$ and ${\beta}-glucosidase$. $C_x-cellulase$ are fairly common but $C_1-cellulase$ are quite rare. Trichoderma viride is the best source of active cellulose, especially $C_1-enzyme$. Saccharification rate of cellulose in greatly influenced by the degree of crystallinity and extent of lignification. But by the pretreatment the substrate with cellulose swelling agent, delignifying reagent and physical treatment, the degree of saccharification is enhanced. Thus, glucose syrups of 2 to 10% concentration are realized from milled newspaper. The enzymatic hydrolysis of such energy rich material, such as cellulose, to glucose is technically feasible and practically achievable on a very large scale.

• Food Science and Biotechnology
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• v.16 no.4
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• pp.565-571
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• 2007

This study was carried out to investigate an optimum condition for the high angiotensin-l converting enzyme (ACE) inhibitory activity and the yield on enzyme concentration, casein concentration, and hydrolysis time. The optimum condition was performed by response surface methodology for acquirement of casein hydrolysate of milk which shows high ACE inhibitory activity, Among 8 tested enzymes, Protamex showed the highest activation degree with 77.03 unit/g from casein. Their hydrolysis degrees of flovourzyme 500MG, protamex, mixture from 1% casein were 85.5, 88.5, and 93.5%, respectively. The ranges of enzyme concentration (0.25-1.25%), casein concentration (2.5-12.5%), and hydrolysis time (20-100 min) as 3 independent variables through preliminary experiments of the yield of casein hydrolysate and ACE inhibitory activity, and it shows optimum response surface at a saddle point. It shows enzyme concentration (0.64%), casein concentration (8.38%), and hydrolysis time (55.81 min) in the yield aspect and showed the highest activity at enzyme concentration (0.86%), casein concentration (5.97%), and hydrolysis time (63.86 min) in ACE inhibitory aspect. The $R^2$ value of a fitted optimum formula on the hydrolysis yield was 0.9751 as the significant level of 1%. The $R^2$ value of a fitted optimum formula on ACE inhibitory activity is 0.8398, and the significance is recognized in the range of 5%.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.5
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• pp.596-602
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• 1993

The Characteristics of Shinsunchalbyeo(Japonica) and Hangangchalbyeo($J{\times}Idica$) starches including physicochemical properties, differential scanning calorimetry(DSC) and enzymatic digestion of lintnerized starches were investigated. Degree of hydrolysis of Hangangchalbyeo starch with 2.2N HCI for 48hr was higher than that of shinsunchalbyeo starch. Absorbance at ${\lambda}_{max}$ 680nm, and ${\lambda}_{max}$ of iodine stained starch decreased upon acid treatment. But water binding capacity, swelling power and solubility considerably increased as hydrolysis progressed. Relative crystallinity of two starches increased with acid treatment, and that of Shinsunchalbyeo starch was higher than that of Hangangchalbyeo starch. DSC data continuously decreased for lintnerization periods, and those of Shinsunchalbyeo starch. DSC data continuously decreased for lintnerization periods, and those of Shinsunchalbyeo starch have higher than those of Hangangchalbyeo starch. The onset temperature of starch by DSC continuously decreased by treatment, but conclusion temperature increased until 24hr and then decreased. The enthalpy for gelatinization decreased for both starches. Degree of hydrolysis of lintnerized Shinsunchalbyeo starch with glucoamylase was slightly higher than that of Hangangchalbyeo starch.

• Journal of Sericultural and Entomological Science
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• v.41 no.1
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• pp.48-53
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• 1999

The study was carried out to investigate the effects of hydrolysis conditions such as treatment times and concentrations on the solubility of insoluble sericin using the hydrochloric acid solution. When insoluble sericin was hydrolyzed by HCl solution, the solubility was increased with the higher treatment concentration. As the results of electrophoresis of sericin powder obtained by the HCl treatment, a distinguishable band was not confirmed. Average degree of polymerizations(A.D.P.) of sericin hydrolyzed by HCl solution were about 4.2~5.9 and average molecular weights(M.W.) were about 470~670. The longer hydrolysis time reduced the whiteness of sericin powder. As the results of amino acid analysis, the amino acid compositions of the sericin powder from HCl treatment were sililar to that of insoluble sericin, but Tyr. and Arg. were not detected in the powder obtained by HCl treatment. In DSC analysis, thermal deformation and pyrolysis peak located at near 220$^{\circ}C$ and 330$^{\circ}C$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.5
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• pp.786-790
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• 1996

The changes in chemical constituents of onion in Korea and the degree of hydrolysis in onion by-drolysates by treatment of viscozyme L, celluclast 1.5L, pectinex and cereflo were investigated. Proximate compositions of onion in Korea were as follows; The contents of moisture, protein, lipid, carbohydrate and ash were 89~90%, 1.8~1.9%, 0.4~0.5%, 7.1~8.5% and 0.3~0.5%, respectively. Major free sugars were identified to be glucose, fructose and sucrose and major free amino acids were as cysteine, histidine, arginine and glutamic acid. The degree of hydrolysis by treatment of viscozyme L, celluclast 1.5L, pectinex and cereflo was 69%, 71%, 80% and 62%, respectively. During the enzymatic hydrolysis, free sugar and total sugar content increased however, pyruvic acid content decreased significantly.

• Korean Journal of Food Science and Technology
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• v.25 no.1
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• pp.39-45
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• 1993

The effects of enzymatic modification with pepsin and actinidin was studied on molecular weight distributions and functional properties of hydrolysates from soy protein isolate (SPI) differing in degree of hydrolysis. The hydrolyzed SPI by pepsin showed 41.5% degree of hydrolysis after 5 min, and maximum hydrolysis was obtained after 2 hours. Actinidin hydrolyzed SPI 26.71% degree after 1 hour. On SDS-PAGE, native SPI showed 9 distinguishable bands on SDS-PAGE gel. Pepsin treated SPI showed one broad band in the lower part of gel. This band was shifted further to the bottom of the gel and became faint as hydrolysis time increased. While actinidin treated SPI showed different SDS-PAGE pattern from pepsin. However PAGE patterns were similar with pepsin and actinidin treated groups. With pepsin treatment, solubility of SPI distinctively increased around isoelectric point(pI). Emulsifying activity (EA) and emulsifying stability (ES) showed marked increase over pH range of $3.0{\sim}8.0$. 5 min modified group had most excellent foam expansion (FE). Foam stability (FS) was increased as pepsin treatment time increased at pI. With actinidin treatment, solubility was increased. 60 min modified SPI had the most effective EA at pH 4.5. However ES was not effected by actinidin treatment. 5 min modified group was most effect in FE. FS was higher at alkaline pH.

• Textile Coloration and Finishing
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• v.7 no.4
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• pp.61-73
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• 1995

Inorganic salts have negative or positive effects on the rates of many chemical reactions and also the rates of acidic and alkaline hydrolysis of carboxylic esters. The direction of salt effects on the hydrolysis of ester depends on the charge of esters. It is expected that the rate of the alkaline hydrolysis of Poly(ethylene terephthalte)(PET), polymeric solid carboxytic polyester with carboxyl end group at the polymer end, is also influenced by inorganic salts. In the present work, to clarify the effect of divalent cations on the alkaline hydrolysis of PET, many salts with divalent cations like $MgCl_{2},CaCl_{2},SrCl_{2},BaCl_{2},$ were added to the aqueous alkaline solutions. Then PET was hydrolyzed with aqueous NaOH solution having many salts under various conditions. Some conclusions obtained from the experimental results were summarized as follows. Many salts with various divalent cations increased or decreased the reaction rate of alkaline hydrolysis of PET depending on their electrophilicity, hydration property, ability of ion pair formation, solubility, and the degree of interactions between divalent cations and anions, etc. The hydrolysis was interrupted in the order of $Ca^{+2} and was generally accelerated in the order of $Ba^{+2}. It was inferred from the increase in ΔS$^*$and the decrease in the ΔG$^*$that the divalent cations $Sr^{+2}$ and $Ba^{+2}$attracted by PET increased the collision frequency between carbonyl carbon and $OH^{-}$ion and then accelerated the reaction rate. $Mg^{+2}$and $Ca^{+2}$decreased the reaction rate because of their strong interaction with $OH^{-}$.

• Korean Journal of Food Science and Technology
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• v.23 no.1
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• pp.25-30
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• 1991

Chicken liver was enzymatically hydrolyzed with an alkaline protease and determined the optimal conditions of reaction temperature and time, pH and enzyme to substrate ratio(E/S ratio) for possible utilization as a protein supplementary ingredient. The functional properties of hydolysate measured were water and oil absorption capacity, emulsifying activity and viscosity and sensory properties were also evaluated. It was found that hydrolysis at $60^{\circ}C$ and pH 8.0 were most effective and the degree of hydrolysis increased with increasing E/S ratio. A decrease in water and oil absorption capacity and an increase in viscosity were found during hydrolysis. The lowest emulsifying activity and highest water absorption were measured for 1/2 hour-hydrolysate and little difference was found for those treated more than 1 hour. The sensory characteristics of odor showed no significant difference among the chicken liver hydrolysates while the brightness increased and red decreased significantly(p<0.01) as the hydrolysis proceeded.

• Preventive Nutrition and Food Science
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• v.5 no.4
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• pp.179-183
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• 2000

$\beta$-1,4-Mannotriose was prepared b he enzymatic hydrolysis of white copra meal (WCM) and the subsequent elimination of monosaccharides from the resultant hydrolysate with a yeast. The enzyme system from sunflower seed hydrolyzed WCM and produced monosaccharides and $\beta$-1,4-mannotriose without other oligomers at the final stage of the reaction. WCM(50g) was hydrolyzed at 5$0^{\circ}C$ and pH 4.5 for 24 hr with crude enzyme solution (500 mL) from sunflower seed. By the elimination of monosaccharides from the hydrolysis products with a yeast (Candida glaebosa), 8.1 g of crystalline mannotriose was obtained without the use of chromatographic techniques. After 48hr of yeast cultivation, the total sugar content decreased from 4.6% to 3.5%, whereas the average degree of polymerization increased from 2.3 to 3.1.