• Korean Chemical Engineering Research
• /
• v.53 no.5
• /
• pp.570-575
• /
• 2015

The green algae have cellulose as a main structural component of their cell wall and the cellulose content in green algae is much higher than other marine algae such as brown algae and red algae. Furthermore, green algae do not contain lignin in their cell wall and store starch as food in their plastids. Thus, it was investigated that the effect of hydrothermal pretreatment process utilizing microwave irradiation for Ulva pertusa Kjellman, a division of green algae, which is expected to be utilized for bioenergy production, on the enzymatic hydrolysis. The hydrothermal temperature have an effect on the pretreatment of Ulva pertusa Kjellman, but the effect of power of microwave irradiation is negligible. The rate of enzymatic hydrolysis was increased as the hydrothermal temperature increased until $140^{\circ}C$. The enzymatic hydrolysis of pretreated Ulva pertusa Kjellman under the optimum pretreatment conditions (50 W of microwave irradiation power and $150^{\circ}C$ of hydrothermal temperature) with cellulase, ${\alpha}$-amylase, and Novozyme 188 having ${\beta}$-glucosidase acitivity resulted in the saccharification of 96 wt% of total carbohydrate in Ulva pertusa Kjellman during 3 hrs, while it took 24 hrs for the enzymatic hydrolysis of untreated Ulva pertusa Kjellman. It confirmed that the hydrothermal pretreatment was effective on Ulva pertusa Kjellman for the enzymatic hydrolysis.

• Korean Journal of Food Science and Technology
• /
• v.31 no.4
• /
• pp.1017-1023
• /
• 1999

Several extraction conditions of mussel were investigated for preparation of the extract as a natural shellfish seasoning. The conditions studied were extraction temperature and time, addition of sodium phosphates and citrate and hydrolysis with commercial proteolytic enzymes. The extracts were prepared by deshelling, grinding and aqueous extraction followed by centrifugation and filtration. Extraction at $90^{\circ}C$ for 40min showed the highest solids yield with less fishy and high umami taste. Among the several phosphates and citrate added, $Na_{3}PO_{4}$ and $Na_{4}P_{2}O_{7}$ at 1% level were most effective in terms of the yield and umami taste. The pH effects showed that pH 10 resulted the highest solids yield of 28% with less fishy taste. Even though the effect of enzymatic hydrolysis was not greatly different among the commercial enzymes tested, Protamex and Protease II were somewhat better than other enzymes in taste. When the mussel were extracted by the combined conditions, hydrolysis with Protamex followed by extraction at $90^{\circ}C$ for 40min with addition of $Na_{3}PO_{4}$ at pH 10, the solid yields increased up to 30% which was about 58% improvement and high intensity of umami taste and less fishy flavor.

• Textile Coloration and Finishing
• /
• v.32 no.1
• /
• pp.9-18
• /
• 2020

In this study, we conducted alkali hydrolysis on sea-island type PET ultramicrofiber tricot fabric and dyeing according to the various conditions with black disperse dye. Herein, we evaluated the weight loss rate and tensile strength according to the NaOH contents. The optimal alkali hydrolysis treatment conditions were set to 25 %omf NaOH with a treatment time of 60 min at 110 ℃, and average weight loss rate of the PET ultramicrofiber tricot fabric is about 23 %. The dyeing conditions were investigated with different dyeing temperatures(95-135 ℃), dyeing time(20-60 min), dye contents(2-10 %omf), dispersant contents(1-9 g/ℓ), pH buffer solution contents(1-9 g/ℓ), UV-absorbent contents(5-25 %omf) and reduction cleaning process conditions for black color. We obtained the optimum conditions of the dyeing with the dye contents of 8 %omf, the dispersant contents of 1 g/ℓ, the pH buffer solution contents of 1 g/ℓ, the UV-absorbent contents of 10 %omf, the dyeing temperature of 135 ℃ and the dyeing time of 40 min. The light colorfastness of dyed ultramicrofiber PET tricot fabric was good to excellent in the range of 4 to 5.

• Korean Journal of Food Science and Technology
• /
• v.31 no.3
• /
• pp.727-733
• /
• 1999

Endo- and exoproteases were used to hydrolyze Alaska pollack processing scrap. In 2 stage hydrolysis, the optimal conditions by Protamex were: temperature, $45.8^{\circ}C$; pH, 6.73; enzyme concentration, 0.11%; time, 105.5 min, whereas those by Flavourzyme were: temperature, $42.0^{\circ}C$; pH, 6.54; enzyme concentration, 0.28%; time, 20.4 hrs. But, the optimal conditions of 1 stage hydrolysis by equal proportion of Protamex and Flavourzyme were: temperature, $52.9^{\circ}C$; pH, 6.3; enzyme concentration, 0.46%; time 10.9 hrs. The contents of carbohydrate and ash were higher in the 2 stage hydrolyzate than the 1 stage, while that of crude lipid was in the reverse order. There were no significant differences in the contents of moisture and crude protein between both methods. The contents of total creatine and IMP, and viable cell counts were higher in the 1 stage hydrolyzate than the 2 stage, while the contents of TMAO, TMA, and Hx was in the reverse order. But, there were no significant differences in the contents of amino-N and color between both methods. The free amino acid contents of the 1 and 2 stage hydrolyzate were 2,741.77 and 3,529.47 mg/100 mL, respectively.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2012.02a
• /
• pp.557-557
• /
• 2012

Silicatein-${\alpha}$, the enzyme extracted from silica spicules in glass sponges, has been studied extensively in the way of chemistry from 1999, in which the pioneering work by Morse, D. E. - the discovery of the enzymatic hydrolysis in Silicatein-${\alpha}$ - was published. Since its reaction conditions are physiologically favored, synthesis of various materials, such as gallium oxide, zirconium oxide, and silicon oxide, was achieved without any hazardous wastes. Although some groups synthesized oxide films and particles, they have not achieved yet controlled morphogenesis in the reaction conditions mentioned above. With the knowledge of catalytic triad involved in hydrolysis of silicone alkoxide and oligomerization of silicic acid, we designed the novel peptide amphiphiles to not only form self-assembled structure, but also display similar activities to silicatein-${\alpha}$. Designed templates were able to self-assemble into left-handed helices for the peptide amphiphiles with L-form amino acid, catalyzing polycondensation of silicic acids onto the surface of them. It led to the formation of silica helices with 30-50 nm diameters. These results were characterized by various techniques, including SEM, TEM, and STEM. Given the situation that nano-bio-technology, the bio-applicable technology in nanometer scale, has been attracting considerable attention; this result could be applied to the latest applications in biotechnology, such as biosensors, lab-on-a-chip, biocompatible nanodevices.

• Korean Journal of Food Science and Technology
• /
• v.47 no.1
• /
• pp.6-12
• /
• 2015

This study was performed to determine the optimal hydrolysis conditions for the production of hydrolysates, including water-soluble dietary fiber from Chinese cabbage, with commercial enzymes. The optimal pH and temperature for hydrolysis of the hemicellulose fraction were pH 5.0 and $40^{\circ}C$, and optimal enzyme concentrations were 45 units and 21 units for Shearzyme plus and Viscozyme L, respectively. The yields of the hydrolysate including the water-soluble dietary fiber from the hemicellulose fraction by Shearzyme plus and Viscozyme L were 22.64 and 24.73%, respectively, after a 72 h reaction. The molecular weight distribution of alcohol-insoluble fiber was characterized by gel chromatography; degradation of hemicellulose increased with increasing reaction time. Our results indicate that the hemicellulose fraction was degraded to water-soluble dietary fiber by enzymatic hydrolysis, and its hydrolysate could be utilized as new watersoluble food materials.

• Journal of Life Science
• /
• v.17 no.9 s.89
• /
• pp.1260-1265
• /
• 2007

Magnetically separable enzyme-coated nanofibers were developed for the hydrolysis of starch. Stability of ${\alpha}-amylase-coated$ nanofiber was greatly improved and its residual activity was maintained over 92.7% after 32 days incubation at room temperature and under shaking conditions (200 rpm). The recovery of enzyme was high and enzyme activity after 10 recycle was 95.2% of its original activity. Developed enzyme-coated nanofibers were used for the hydrolysis of starch. When 0.5 mg of magnetically separable enzyme nanofibers was used, 40 g/l of starch (2 ml) was completely degraded within 40 min. The continuous enzyme reactor was developed and used for starch hydrolysis and 76% of starch (30 g/l) was hydrolyzed with 1 hr residence time.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.23 no.3
• /
• pp.51-59
• /
• 2015

Livestock sludge contains high concentration of organic matter and some heavy metals. In case of discharging into the sea, it might have negative effects in the environment. In this study thermal hydrolysis reaction was applied for livestock sludge to determine the fuelization possibility and obtain the best operation conditions. Livestock sludges were thermally hydrolyzed at temperature range $170{\sim}210^{\circ}C$ in sealed high-temperature reactors. Liquid products and dewatered cakes were analyzed. The operation at $190^{\circ}C$ was found to be best effective condition. High heating value and low heating value were 5,050 kcal/kg and 4,740 kcal/kg, respectively. Therefore, fuelization of livestock sludge using thermal hydrolysis reactor is found to be highly effective.

• Journal of Pharmaceutical Investigation
• /
• v.33 no.2
• /
• pp.91-97
• /
• 2003

During the preparation of decoction from the mixture of Coptidis Rhizoma and Scutellariae Radix, insoluble copreciptate was formed. The coprecipitated product (COP) was composed of berberine and baicalin which was the active ingredient of Coptidis Rhizoma and Scutellariae Radix, respectively. COP was slightly soluble in water and could not be well absorbed after oral administration. This poor bioavailibility might be associated with its poor aqueous solubility. With the purpose of increasing the solubility and bioavailibility of COP, hydrolysis of COP by ${\beta}-glucuronidase$ was carried out. Hydrolyzed products (HOP) of COP were identified and assayed for active ingredients. The partition coefficient study, in situ absorption test, and pharmacokinetic study after oral administration were also performed. COP was found to be consisted of berberine and baicalin with molecular ratio of 1 to 1. This compound was hydrolyzed to berberine and baicalin by ${\beta}-glucuronidase$. The rate of hydrolysis was higher at higher temperature up to $50^{\circ}C$ and higher concentration of ${\beta}-glucuronidase$ up to 2500 unit under our experimental conditions. Baicalein, which is more liphophilic than baicalin, showed greater absorption in small intestine than baicalin did. The plasma concentrations of berberine and baicalein after oral administration of HOP were significantly higer than those of COP. The possible mechanism of increased bioavailibility of berberine and baicalein could be the hydrolysis of COP by ${\beta}-glucuronidase$. On the basis of the above results, it might be said that HOP should be a suitable preparation for increasing the bioavailibility of Coptidis Rhizoma and Scutellariae Radix.

• Microbiology and Biotechnology Letters
• /
• v.25 no.2
• /
• pp.166-172
• /
• 1997

Aspergillus niger was selected as a strain producing the potent raw starch hydorlyzing enzyme. These experiments were conducted to investigate the conditions of the glucoa- mylase production, the purification of the enzyme, some characteristics of the purified enzyme and hydrolysis rate on various raw starches such as com, rice, potato, glutinous rice, sweet potato, wheat and barley. The optimum cultural temperature and time for the enzyme production on wheat bran medium were $30^{\circ}C$ and 96hrs, respectively. The respective addition of yeast extract and nutrient broth on wheat bran medium increased slightly the enzyme production. The enzyme was purified by ammonium sulfate fractionation and DEAE-cellulose column chromatography. The specific activity of the purified enzyme was 30.7u/mg-protein and the yield of enzyme activity was 25.8%. The purified enzyme showed a single band on polyacrylamide disc gel electrophoresis and its molecular weight was estimated to be 56,000 by SDS-polyacrylamide disc gel electrophoresis. The isoelectric point for the purified enzyme was pH3.7. The optimum temperature and pH were $65^{\circ}C$ and pH 4.0, respectively. The purified enzyme was stable in the pH range of pH 3.0-9.5 and below $45^{\circ}C$, and its thermal stability was slightly increased by the addition of $Ca^{2+}$. The purified enzyme was activated by $Co^{2+},\;Sr^{2+},\;Mn^{2+},\;Fe^{2+},\;Cu^{2+}$. Raw rice starch, raw corn starch, raw glutinous rice starch, raw sweet potato starch, raw wheat starch and raw barley starch showed more than 90% hydrolysis rate in 48hrs incubation. Even raw potato starch, most difficult to be hydrolyzed, showed 80% hydrolysis rate. The purified enzyme was identified as glucoamylase.