• Title/Summary/Keyword: hydrolysis index

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Improvement of Rheological and Functional Properties of Salmon FPC by Enzymatic Partial Hydrolysis 2. Rheological and functional properties of salmon FPC hydrolysates

  • LEE Jong-Ho;LEE Keun-Tai;PARK Seong-Min;PARK Chan-kyu
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.30 no.6
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    • pp.956-963
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    • 1997
  • To enhance application of FPC in food industry, salmon FPC hydrolysates were produced and their functional properties were investigated. Hydrolysates of salmon FPC showed high solubilities ranged from approximately $80\~95\%$. Emulsifying activity index (EAI) values of hydrolysates were higher than that of egg white, however sugar ester showed the highest EAI value of 32.5. Though sugar ester had the best emulsifying stability value $({\Delta}EAI)$ of 9.65, hydrolysates showed better ${\Delta}EAI$ value than that of egg white. Foam Activity of hydrolysates was predominantly better than those of controls and also foam stability value showed similiar trend. Osmolality of hydrolysates was increased with the increase of degree of hydrolysis (DH) and concentration of protein, but it showed very lower osmolality than that of NaCl. Flow property of hydrolysates showed different upward-downward curves, and hysteresis loop increased with the increase of DH. ACE inhibitory activity showed similiar value ranged from $21.1\~24\%$ at all DH values.

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Supercritical Water Hydrolysis of Waste Logs after Oak Mushroom Production (초임계수를 이용한 표고버섯 골목의 가수분해)

  • Koo, Bon-Wook;Lee, Jae-Won;Choi, Joon-Weon;Choi, Don-Ha;Choi, In-Gyu
    • Journal of the Korean Wood Science and Technology
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    • v.34 no.6
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    • pp.81-95
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    • 2006
  • In order to investigate the possibility of waste logs after oak mushroom production as a source of an alternative energy and to obtain the fundamental data of supercritical water hydrolysis that has been paid attention as a new saccharification method of lignocellulosics, supercritical water hydrolysis of normal log woods (Quercus acutissima Carruth) and waste logs was carried out. With the increase of reaction time and temperature, the color of the degradation products has been dark and the degradation rate and the crystalline index increased. However the increase of reaction pressure affected the color of the degradation products and the degradation rate at only low reaction temperature. In the early stage of the reaction, the degradation of hemicellulose was progressed, while in the late stage, the cellulose was degraded. The increase of reaction time and reaction temperature (less than $415^{\circ}C$) improved the sugar yield, while at high temperature(more than $415^{\circ}C$), the sugar yield was decreased. Based on the result of the sugar yield, the optimal hydrolysis condition of Q. acutissima Carruth by supercritical water was determined to be $415^{\circ}C$, 60 seconds and 230 pressure bar with the sugar yield of 2.68% (w/w). At the optimal condition, the supercritical water hydrolysis of waste logs after the mushroom production was carried out and the sugar yield was increased to 358% (w/w). The major degradation products of waste logs by supercritical water hydrolysis were 1,1'-oxybis-benzene and 1,2-benzendicarboxylic acid by the GC-MS analysis. At the reaction condition with low degradation rate, the fatty acids such as pentadecanoic acid, 14-methyl-heptadecanoic acid were identified. With the increase of the reaction temperature and time, the amounts of phenol and benzene were increased, but the reaction pressure did not affect the kinds of degradation products. Holocellulose content was 60.6~79.2% in the water insoluble residue and the monosaccharide yield of the water insoluble residue was 49.2~675% by the acid hydrolysis. The monosaccharide yield of water-soluble portion was increased largely by the second hydrolysis using dilute acid.

ACE Inhibitory and Antioxidative Activities of Silkworm Larvae (Bombyx mori) Hydrolysate (번데기 가수분해물의 ACE 저해활성과 항산화활성)

  • Yu, Jung-Sik;Woo, Koan-Sik;Hwang, In-Guk;Lee, Youn-Ri;Kang, Tae-Su;Jeong, Heon-Sang
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.37 no.2
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    • pp.136-140
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    • 2008
  • In order to utilize the silkworm larvae (Bombyx mori) protein, defatted silkworm protein was hydrolysed by four enzymes (pepsin, trypsin, neutrase and alcalase) at various hydrolysis times (6, 12, 18, 24 and 30 hr) and suspension concentrations (2, 5, 10, 15 and 20%). Protein solubility index, ACE (angiotensin converting enzyme) inhibitory activity and antioxidative activity of silkworm protein hydrolysates were investigated. The optimum condition of hydrolysis was 10% suspension concentration and 18 hr. Protein solubility index of trypsin treatment was higher than other enzyme treatments. ACE inhibitory activity and $IC_{50}$ value of antioxidative activity of neutrase treatment were 86.16% at $100\;{\mu}g/mL$ and $352.75\;{\mu}g/mL$, respectively; also, these values were higher than other enzyme treatments.

Preparation of Hard Coating Films with High Refractive Index from Titania Nanoparticles (이산화티탄 나노입자로부터 고굴절 하드코팅 도막의 제조)

  • Kim, Nam Woo;Ahn, Chi Yong;Song, Ki Chang
    • Korean Chemical Engineering Research
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    • v.53 no.6
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    • pp.762-769
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    • 2015
  • The titania ($TiO_2$) nanoparticles with a diameter 2?3 nm were synthesized by controlling hydrolysis of titanium tetraisopropoxide (TTIP) in acid solution. Organic-inorganic hybrid coating solutions were prepared by reacting the titania nanoparticles with 3-glycidoxypropyl trimethoxysilane (GPTMS) by the sol-gel method. The hard coating films with high refractive index were obtained by curing thermally at $120^{\circ}C$ after spin-coating the coating solutions on the polycarbonate (PC) sheets. The coating films showed high optical transparency of 90% in the visible range and exhibited a pencil hardness of 2H. Also, the refractive index at 633 nm wavelength of coating films enhanced from 1.502 to 1.584 as the weight content of titania nanoparticles in the coating solutions increased from 4% to 25%.

Studies for Physicochemical and In Vitro Digestibility Characteristics of Flour and Starch from Chickpea (Cicer arietinum L.)

  • Chung, Hyun-Jung
    • Preventive Nutrition and Food Science
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    • v.16 no.4
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    • pp.339-347
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    • 2011
  • Flour and isolated starch from chickpea (desi type, 328S-8) were evaluated for their in vitro digestibility and physicochemical properties. The protein content, total starch content and apparent amylose content of chickpea flour and isolated starch were 22.2% and 0.6%, 45.8% and 91.5%, and 11.7% and 35.4%, respectively. Chickpea starch granules had an oval to round shape with a smooth surface. The X-ray diffraction pattern of chickpea starch was of the C-type and relative crystallinity was 24.6%. Chickpea starch had only a single endothermic transition (13.3 J/g) in the DSC thermogram, whereas chickpea flour showed two separate endothermic transitions corresponding to starch gelatinization (5.1 J/g) and disruption of the amylose-lipid complex (0.7 J/g). The chickpea flour had a significantly lower pasting viscosity without breakdown due to low starch content and interference of other components. The chickpea starch exhibited significant high setback in the viscogram. The average branch chain length, proportion of short branch chain (DP 6~12), and long branch chains (DP${\geq}$37) of isolated chickpea starch were 20.1, 20.9% and 9.2%, respectively. The rapidly digestible starch (RDS), slowly digestible starch (SDS) and resistant starch (RS) contents of chickpea flour and starch were 9.9% and 21.5%, 28.7% and 57.7%, and 7.1% and 9.3%, respectively. The expected glycemic index (eGI) of chickpea flour (39.5), based on the hydrolysis index, was substantially lower than that of isolated chickpea starch (69.2).

The Effect of Cellulase on the Pore Structure of Cellulose Fibers

  • Park, Sun-Kyu;Venditti Richard A.;Abrecht David G.;Jameel Hasan;Pawlak Joel J.;Lee, Jung-Myoung
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2006.06a
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    • pp.43-49
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    • 2006
  • The surface and pore structure of cellulose fibers have a significant impact on the properties and performance in applications. Cellulase enzymatic hydrolysis of cellulose fibers can result in changes to the surface and pore structure thus providing a useful tool for fiber modification. This research characterizes these changes using various test methods such as fiber dimension, water retention value, hard-to-remove water content, freezing and non-freezing bound water content, polymer adsorption, and crystallinity index. For a high-dosage enzyme treatment (0.10 g/g), the fiber length was significantly decreased and the fibers were 'cut' in the cross direction, not in the axial direction. The swelling capacities as measured by the WRV and HR water content increased for the high-dosage treatment. Three independent measurements (non-freezing bound water, polymer adsorption, and crystallinity index) are in good agreement with the statement that the amorphous regions of cellulose fibers are a more readily available substrate relative to crystalline regions. Based on the experimental results obtained herein, a model was proposed to explain surface and pore structure modification of cellulose fibers via enzymatic treatment.

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Tenderness-related index and proteolytic enzyme response to the marination of spent hen breast by a protease extracted from Cordyceps militaris mushroom

  • Barido, Farouq Heidar;Lee, Sung Ki
    • Animal Bioscience
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    • v.34 no.11
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    • pp.1859-1869
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    • 2021
  • Objective: The effects of a crude protease extracted from Cordyceps militaris (CM) mushrooms on the postmortem tenderization mechanism and quality improvement in spent hen breast were investigated. Methods: Different percentages of the crude protease extracted from CM mushrooms were introduced to spent hen breast via spray marination, and its effects on tenderness-related indexes and proteolytic enzymes were compared to papain. Results: The results indicated that there was a possible improvement by the protease extracted from CM mushroom through the upregulation of endogenous proteolytic enzymes involved in the calpain system, cathepsin-B, and caspase-3 coupled with its nucleotide-specific impact. However, the effect of the protease extracted from CM mushroom was likely dose-dependent, with significant improvements at a minimum level of 4%. Marination with the protease extracted from CM mushroom at this level led to increased protein solubility and an increased myofibrillar fragmentation index. The sarcoplasmic protein and collagen contents seemed to be less affected by the protease extracted from CM mushroom, indicating that substrate hydrolysis was limited to myofibrillar protein. Furthermore the protease extracted from CM mushroom intensified meat product taste due to increasing the inosinic acid content, a highly effective salt that provides umami taste. Conclusion: The synergistic results of the proteolytic activity and nucleotide-specific effects following treatments suggest that the exogenous protease derived from CM mushroom has the potential for improving the texture of spent hen breast.

Starch Content and in vitro Hydrolysis Index of Rice Varieties Containing Resistant Starch (저항전분 함유 쌀 품종의 로스팅(Roasting)에 따른 전분 함량 및 in vitro 가수분해지수)

  • Park, Jiyoung;Lee, Seuk Ki;Choi, Induck;Choi, Hye Sun;Shin, Dong Sun;Park, Hye Young;Han, Sang-Ik;Oh, Sea-Kwan
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.63 no.4
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    • pp.304-313
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    • 2018
  • The objective of this study was to investigate the resistance starch(RS) content and in vitro hydrolysis index of roasted rice flours for low GI food development. This study used intermediate and high amylose rice varieties containing resistant starch. The intermediate amylose rice varieties 'Ilmi' and high amylose rice varieties, 'Goami4' and 'Dodamssal' were tested. The crude fat and crude protein contents of the rice cultivars ranged 2.12~3.08% and 6.2~7.63%, respectively. The RS and amylose contents of Dodamssal and Goami4 were higher than those of Ilmi. RS content of Ilmi was not significantly different before and after roasting treatment. The RS content of Goami4 before roasting was significantly higher than that of Dodamssal, but the RS content of Dodamssal was higher than that of Goami4 at temperatures above $210^{\circ}C$ of roasting. The soluble starch decreased after roasting in Goami4 and Dodamssal. Starch hydrolysis index (HI) and expected glycemic index (GI) were higher in order of Imi, Goami4 and Dodamssal regardless of roasting treatment. The sensory evaluation showed high scores in Dodamssal for color, flavor, bitter taste, bitter taste, sweet taste and sweetness at $240^{\circ}C$ for 10 min and $210^{\circ}C$ for 30 min. The results of this study indicate that Dodamssal was suitable varieties for powder meal with low GI.

The Effect of Dextranase-Containing Mouthwash in Human Experimental Gingivitis (실험적 치은염에서 dextranase 함유 구강 세정액의 양치 효과)

  • Son, Eun-Ju;Kim, Young-Jun;Kim, Do-Man;Chung, Hyun-Ju
    • Journal of Periodontal and Implant Science
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    • v.31 no.2
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    • pp.401-420
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    • 2001
  • A novel glucanhydrolase from a mutant of Lipomyces starkeyi(KSM 22)has been shown effective in hydrolysis of mutan, reduction of mutan formation by Streptococcus mutans and removal pre-formed sucrose-dependent adherent microbial film and Lipomyces starkeyi KSM 22 dextranase has been strongly bound to hydroxyapatitie. These in vitro properties of Lipomyces starkeyi KSM 22 dextranase are desirable for its application as a dental plaque control agent. This study was performed to determine oral hygiene benefits and safety of dextranase(Lipomyces starkeyi KSM 22 dextranase)-containing mouthwash in human experimental gingivitis. This 3-week clinical trial was placebo-controlled double-blind design evaluating 1U/ml dextranase mouthwash and 0.12% chlorhexidine mouthwash. A total 39 systemically healthy subjects, who had moderate levels of plaque and gingivitis were included. At baseline, 1, 2 and 3 weeks, subjects were scored for plaque(Silness and $L{\ddot{o}e$ plaque index and plaque severity index), gingivitis($L{\ddot{o}e$ and Silness gingival index), and at baseline and 3 weeks of experiment, subjects were scored for plaque(Turesky-Quingley-Hein's plaque index and plaque severity index), tooth stain(Area and severity index system by Lang et al). Additionally, oral mucosal examinations were performed and subjects questioned for adverse symptoms. Two weeks after pre-experiment examinations and a professional prophylaxis, the subjects provided with allocated mousewash and instructed to use 20-ml volumes for 30s twice dailywithout toothbrushing. All the groups showed significant increase in plaque accumulation since 1 week of experiment. During 3 weeks' period, the dextranase group showed the least increase in plaque accumulation of Silness and $L{\ddot{o}e$ plaque index, compared to the chlorhexidine and placebo groups, but chlorhexidine group showed the least increase inplaque accumulation of Turesky-Quingley-Hein's plaque index. As for gingival inflammation, all the groups showed significant increase during 3 weeks of experiment. The dextranase group also showed the least increase in gingival index score, compared to the chlorhexidine as well as the placebo groups. Whereas the tooth stain was increased significantly in the chlorhexidine group, compared to the baseline score and the placebo group since 3 weeks of mouthrinsing. It was significantly increased after 3 weeks in the dextranase group, still less severe than the chlorhexidine group. As for the oral side effect, the dextranase group showed less tongue accumulation, bad taste, compared to the chlorhexidine group. From these results, mouthrinsing with Lipomyces starkeyi KSM 22 dextranase was comparable to 0.12% chlorhexidine mouthwashin inhibition of plaque accumulation and gingival inflammation and local side effects were if anything less frequent and less intense than chlorhexidine, in human experimental gingivitis. All data had provided positive evidence for Lipomyces starkeyi KSM 22 dextranase as an antiplaque agent and suggested that further development of dextranase formulations for plaque control are warranted.

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Effect of partial sintering of silicate soots on refractive index of the silcate glass films deposited by FHD Process (FHD 공정으로 Si wafer에 증착된 silicate soot의 부분 소결 처리가 굴절률 변화에 미치는 영향)

  • 유성우;정우영;백운출;한원택
    • Proceedings of the Optical Society of Korea Conference
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    • 2002.07a
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    • pp.46-47
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    • 2002
  • Flame Hydrolysis Deposition (FHD) 공정은 SiC1$_4$, GeCl$_4$, POC1$_3$, BCl$_3$ 등의 원료를 사용하여 Si wafer 및 유리기판 위에 silicate soot를 증착하는 방법이며, 증착된 soot는 고온에서 소결과정을 거쳐 B$_2$O$_3$-P$_2$O$_{5}$ -GeO$_2$-SiO$_2$(BPGS)계 유리막으로 형성된다. 유리막의 굴절률은 SiC1$_4$, GeCl$_4$, POC1$_3$, BCl$_3$ 등의 원료 유량을 조절하여 변화가능하며 이를 이용하여 광도파로를 제작할 수 있다 특히 광통신에 사용할 수 있는 광증폭기 등의 능동형 광소자 제작을 위해서는 FHD공정을 통해 형성된 soot에 Er$^{3+}$ 등의 희토류 원소를 첨가하여야 한다. (중략)

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