• Korean Chemical Engineering Research
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• v.54 no.1
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• pp.1-5
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• 2016

For obtain fermentable sugar, we conducted acid hydrolysis with lignocellulosic biomass without enzyme. The lignocellulosic biomass used pinus rigida and Palm residues (EFB; empty fruit bunches). In the acid hydrolysis, we consider the hydrolysis condition to reduce a denatured sugar. So this study was conducted 2-step acid hydrolysis. First-step hydrolysis used high concentration (72 wt%) sulfuric acid at $80^{\circ}C$. At the condition, we obtained 11.49 wt%, 32 wt% glucose conversion for pinus rigida and EFB. After the step, the liquor was dilute until 9~15 wt% acid concentration and conducted second hydrolysis at $50{\sim}120^{\circ}C$. In the second hydrolysis, we obtained maximum glucose conversion (pinus rigida 86.8 wt% (39 g/L) and EFB 95.3 wt% (32.4 g/L)) at 9 wt% acid concentration and $120^{\circ}C$ for 80 min. All samples through the process are analyzed on the basis of mass balance.

• Clean Technology
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• v.7 no.4
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• pp.281-290
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• 2001

A microwave-assisted process to prepare chitosan from natural crabshells has been investigated. This study was primarily to examine the effectiveness of microwave as clean energy for chitosan preparation. Several human-edible organic acids were used as clean catalyst, possibly to improve the current HCl-based hydrolysis process of polymeric chitosan. The microwave was found to be effective substantially in reducing the reaction time. Nonetheless, no beneficial effect of microwave other than time, such as the chemical selectivity, was hardly observed. The organic acids were very effective in the hydrolysis reaction of polymeric chitosan. Their catalytic behavior was greatly improved especially when reactions were performed under pressure. In the case of autoclave reaction for 60 minutes at $120^{\circ}C$, viscous solution of polymeric chitosan (mol. wt. > 300,000) turned into thin solutions of water-like viscosity, which means chitosan molecules were decomposed to very small-sized oligomers.

• Korean Journal of Food Science and Technology
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• v.23 no.1
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• pp.62-67
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• 1991

The characteristics of Tongjinbyeo(Japonica) and Samgangbyeo($J{\times}Indica$) rice starches including physicochemical properties, differential scanning calorimetry and enzymatic digestion of lintnerized starches were investigated. Degree of hydrolysis of Tongjinbyeo starch with 2.2N HCI for 48 hr was higher than that of Samgangbyeo starch. Apparent first order reaction of starches was slow reaction for first period, and fast reaction second period on the datum point of acid treatment 24 hr. Absorbance at ${\lambda}_{max}$ and 680 nm, and ${\lambda}_{max}$ of iodine stained starch and amylose content 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 Tongjinbyeo starch was higher than that of Samgangbyeo starch. Differential scanning colorimetry(DSC) data continuously decreased for lintnerization periods, and those of Tongjinbyeo starch have higher than those of Samgangbyeo starch. The onset temperature of starch by DSC continuously decreased by treatment, but conclusion temperature increased until 24 hr and then decreased. The enthalpy for gelatinization decreased for both starches. Degree of hydrolysis of lintnerized Tongjinbyeo starch with glucoamylase was slightly higher than that of Samgangbyeo starch.

• Journal of the Korean Applied Science and Technology
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• v.33 no.1
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• pp.176-185
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• 2016

Yeonsan Ogae has been known as supporting health and high efficacy of treatment. In recent days, as the efficacy of functional peptides has known, the optimization of oligo peptides production and its characteristics from Ogae legs has been performed. Response surface method was used to perform the optimizaion of enzyme hydrolysis. The range of processes was temperature ( 40, 50 and $60^{\circ}C$), pH( pH 6.0, 7.0 and 8.0 ), and enzyme( 1, 2 and 3% ). The degree of hydrolysis, amino acids, molecular weight of products were analyzed. The optimum process of enzyme hydrolysis were determined as temperature $58^{\circ}C$, pH 7.5, and enzyme concentration 3%. At optimum conditions, the degree of hydrolysis after 2 h reaction was 75-80%. The amino acid and were 168.131 mg/100 g, respectively. The molecular weight of products by using MALDI-TOF was ranged from 300 to 1,000 Da.

• KSBB Journal
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• v.8 no.4
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• pp.358-363
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• 1993

The effect of ultrasound on the acid hydrolysis of inulin was studied under significantly mild reaction conditions, at which sugar degradation products were not detected. Reaction conditions were i the range of 50~$60^{\circ}C$ and 0.1~0.3%(w/w) of HCl concentrations. The effects of reactor position inside water bath and mechanical agitation under ultrasound were investigated. The production rates of fructose with/without ultrasound irradiation were compared. The activation energies for both control and ultrasound reaction were the same, i. e., 25kca1/mo1, and ultrasound enhancement was average 22%.

• Korean Chemical Engineering Research
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• v.50 no.1
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• pp.141-148
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• 2012

In order to study the utilization of brown seaweed Laminaria japonica as an alternative renewable feedstock for bioethanol production, the properties of acid hydrolysis and ethanol fermentation were investigated. The acid hydrolysis enhanced the final yield of fermentable sugars, which led great increase of ethanol productivity. The maximum yield of reducing sugars reached 135 mg/g-dry Laminaria japonica after 1.0N sulfuric acid-hydrolysis at $130^{\circ}C$ for 6 h. The Saccharomyces cerevisiae (ATCC 24858) could ferment $C_6$-sugars like glucose, galactose and mannose into ethanol, but not $C_5$-sugars like arabinose and xylose. Optimal fermentation time varied with sugars; 48 h for glucose, 72 h for galactose, and 96 h for mannose. Nevertheless, the ethanol yield from the hydrolysate reached 242 mg/g-dry Laminaria japonica after fermentation by the S. cerevisiae at $35^{\circ}C$ for 96 h, which corresponds to approximately 4 times more than the theoretical yield from total reducing sugars in the hydrolysates. It indicates that the non-reducing sugars or oligosaccharides dissolved in the hydrolysate played an important role in producing bioethanol. The ethanol concentration linearly increased from 2.4 to 9.2 g/L, while the ethanol yield per dry weight of biomass decreased from 242 to 185 mg/g, with increasing the ratio of biomass to acid solution from 1 to 5% (w/v). The bioethanol yield estimated was approximately 7,400~9,600 kg/ha/year, and indicated that Laminaria japonica is a promissing feedstock for bioethanol production.

• Applied Biological Chemistry
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• v.42 no.2
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• pp.152-155
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• 1999

Effects of pH, amino acids, hydrolyzed protein and potassium phosphate on caramelization were investigated for improvement of its reaction rate. The caramelization was performed with starch syrup at $110^{\circ}C$ and the different color functions-metric saturation(Suv), 5-hydroxymethylfurfural (HMF) contents and absorbance at 420 nm were measured. As the pH was raised from 4 to 10, the reaction rate (Suv/hr) was increased by 31.9% along with significant increase in HMF content and absorbances at 420 nm. Among the several amino acids, arginine and glycine were very effective for improvement of caramelization, which may be due to Maillard reaction. When $K_2HPO_4$ were added in different ratio with arginine, glycine, HVP or HAP, the effects of arginine and HAP on thee rate were markedly enhanced while the effects of glycine and HVP were rather reduced.

• Korean Journal of Food Science and Technology
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• v.45 no.1
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• pp.34-39
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• 2013

This study was performed to investigate the antioxidant activity of mung beans with heat treatment at $130^{\circ}C$ for 2 h after acid hydrolysis. The browning index of heating after hydrolysis was 2.31 whereas heating before hydrolysis was 0.17. 5-hydromethyl-2-furaldehyde (5'-HMF) content was the highest value of 81.61 mg/g in heating after hydrolysis. The highest total polyphenol content (55.95 mg/g) occurred in heating after hydrolysis and this value was 6.4-fold higher than that of heating before hydrolysis (8.79 mg/g). 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging activity was the highest value of 22.19 mg AA eq/g sample in heating after hydrolysis whereas heating before hydrolysis was 1.75 mg AA eq/g sample.1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity was the highest value of 3.64 mg Trolox eq/g sample in heating after hydrolysis whereas heating before hydrolysis was not shown. These results suggest that heat treatment of mung beans for increasing the antioxidant activity could be effective after hydrolysis.

• KSBB Journal
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• v.13 no.1
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• pp.114-118
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• 1998

The effects of fibron solubilization conditions on molecular weight distribution of enzymatically-hydrolyzed silk peptides were investigated. The weight-averaged molecular weights of silk proteins prepared by solubilization with calcium chloride, ethylenediamine and sulfuric acid were 41600, 3308, and 1268 dalton, respectively. Silk peptides in the average molecular weight range of 600-1200 dalton were obtained by protease treatment from solubilized silk fibroin. After the acid hydrolysis of silk protein using hydrochloric acid for 24 hr, silk protein was hydrolyzed to peptides whose average molecular weight and free amino acid content were 145 dalton and 80%, respectively. It was possible to control molecular weight distribution of silk peptides by the combination of solubilization and hydrolysis methods. Among the various treatment methods, acid solubilization followed by protease treatment had an advantage of molecular weight control for the peptide production.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.8
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• pp.1022-1030
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• 2007

For the improvement on the quality and functionality of red tanner crab cooking drip, the preparation of hydrolysates from red crab cooking drip using commercial enzymes (Alcalase, Flavourzyme, Neutrase and Protamex) was attempted and its taste, nutritional and functional characteristics were also investigated. According to the results of heavy metal contents and proximate composition, red tanner crab cooking drip (RTCCD) could be used as a food resource. From the results of the trichloroacetic acid soluble index (TSI), angiotensin I converting enzyme (ACE) inhibiting activity and antioxidative activity, RTCCD hydrolysates incubated with Alcalase for 2 hrs was superior to the other one-step hydrolysates. There were no differences in the ACE inhibiting activity and antioxidative activity between one-step hydrolysates, which was incubated with Alcalase for 2 hrs, and two-step hydrolysates sequentially incubated with Alcalase and other enzymes. Alcalase-treated hydrolysates was similar in proximate composition and Hunter color value, while high in free amino acid content compared with crab cooking drip. Total amino acid content of Alcalase-treated hydrolysates was 11.9 g/100 mL and the major amino acids were glutamic acid (10.2%), proline (10.1%) and glycine (10.7%).