• Korean Journal of Food Science and Technology
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• v.16 no.2
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• pp.211-217
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• 1984

To study affinity of proteolytic enzymes to soy proteins, the physicochemical and functional properties of enzymatically modified protein products, kinetic parameters and degree of hydrolysis were measured using trypsin, alcalase (serine type protease) and pronase. Bacterial alcalase and pronase showed much greater affinity to soy protein than animal intestinal trypsin. This effect was very significant when unheated soy isolate was used as a substrate. Specific activities of these enzymes decreased with the increment of substrate concentration (over 2.0%, w/v) when heat denatured soy protein was used as a substrate. However, the decrease in specific activity was negligible at substrate concentrations lower than 2.0%. Polyacrylamide gel electrophoretic results showed that the pattern of 2S protein band changed distinctly in alcalase hydrolysis as compared with those of trypsin and pronase. Protein solubilities of alcalase and pronase hydrolyzates increased by 25-30%, at their pI (pH 5.0) over the control. Virtually no change was observed in solubility by trypsin hydrolysis. Heat coagulability and calcium-tolerance of the protein increased by enzymatic hydrolysis. No clear tendency, however, was observed for emulsion properties, foam expansion and the amount of free -SH groups. The enzyme treatment considerably decreased foam stability.

• Korean Journal of Weed Science
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• v.17 no.2
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• pp.135-138
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• 1997

Sulfonylureas are highly active herbicides which can be applied at very low rate(10-50g/ha) to control broadleaf weeds. The nature of this category of compound is, however, very unstable toward hydrolysis. Therefore, the preparation of these compounds as liquid formulation was not possible. Most of the current formulations of sulfonylurea are in dry forms such as water dispersible granule or wettable powder. Even in these dry forms, the active ingredients also encounter significant chemical decomposition. This study involves the preparation of the sulfonylurea salts by reacting the parent compound with base such as sodium hydroxide. The salt becomes stable toward hydrolysis and it turns soluble when diluted with water. This discovery makes the preparation for liquid formulation or soluble granule of sulfonylurea possible. The stoichiometry of base added to the neutral sulfonylurea is controlled quite precisely. The base has to be added enough to quench the acidic impurities in the technical material and to convert the active ingredient into salt. However, the base should not be overused to cause further saponification of the sulfonylurea salts. The chemical nature of these compounds is presented and the chemical reaction is described. New soluble liquid formulation and solid granule formulation of sulfonylurea are suggested.

• Journal of Microbiology and Biotechnology
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• v.24 no.6
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• pp.788-794
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• 2014

An extracellular ${\beta}$-glucosidase from Aspergillus niger Au0847 was purified to homogeneity by precipitation with ammonium sulfate, anion exchange, and gel filtration. The purified protein was composed of two subunits with molecular masses of 110 and 120 kDa. Au0847 ${\beta}$-glucosidase exhibited relatively high thermostability and pH stability, and its highest activity was obtained at $65^{\circ}C$ and pH 4.6, respectively. As a potential metalloprotein, its enzymatic activity was potently stimulated by manganese ion and DTT. The ${\beta}$-glucosidase displayed avid affinity and high catalytic efficiency for geniposide. Au0847 ${\beta}$-glucosidase has potential value as an industrial enzyme for the hydrolysis of geniposide to genipin.

• Journal of Microbiology and Biotechnology
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• v.8 no.4
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• pp.318-324
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• 1998

A ${\beta}$-galactosidase with high transgalactosylic activity was purified from a Bacillus species, registered as KFCC10855. The enzyme preparation showed a single protein band corresponding to a molecular mass of 150 kDa on SDS-PAGE and gave a single peak with the estimated molecular mass of 250 kDa on Sephacryl S-300 gel filtration, suggesting that the enzyme is a homodimeric protein. The amino acid and sugar analyses revealed that the enzyme is a glycoprotein, containing 19.2 weight percent of sugar moieties, and is much more abundant in hydrophilic amino acid residues than in hydrophobic residues, the mole ratio being about 2:1. The pI and optimum pH were determined to be 5.0 and 6.0, respectively. Having a temperature optimum at $70^{\circ}C$ for the hydrolysis of lactose, the enzyme showed good thermal stability. The activity of the enzyme preparation was markedly increased by the presence of exogenous Mg (II) and was decreased by the addition of EDTA. Among the metal ions examined, the most severely inhibitory effect was seen with Ag (I) and Hg (II). Further, results of protein modification by various chemical reagents implied that 1 cysteine, 1 histidine, and 2 methionine residues occur in certain critical sites of the enzyme, most likely including the active site. Enzyme kinetic parameters, measured for both hydrolysis and transgalactosylation of lactose, indicated that the enzyme has an excellent catalytic efficiency for formation of the transgalactosylic products in reaction mixtures containing high concentrations of the substrate.

• Preventive Nutrition and Food Science
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• v.20 no.4
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• pp.284-291
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• 2015

In this study, we attempted to enrich cyclo-His-Pro (CHP) using enzymatic hydrolysis of yeast and to evaluate the functionality of yeast hydrolysate (YH)-enriched CHP. Flavourzyme offered a better performance in enhancing CHP content than other proteases. The CHP enrichment conditions were optimized as follows: addition of 1% Flavourzyme, 48-h incubation at 60oC, and pH 6.0. The CHP content significantly increased by 20-fold after ultra-filtration (UF). Maximal CHP translation was obtained after heating for 8 h at 50oC and pH 7.0. YH showed poor foaming capacity between pH 3.0 to 9.0. The emulsifying activities of YHs were slightly higher at near acidic pH. Increase in heating temperature and time resulted in decreased CHP content. The results indicate that YH is more heat stable after UF. Therefore, the CHP in YH after UF can be used as a food additive with physiological CHP activity and high heat stability.

• Fisheries and Aquatic Sciences
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• v.16 no.2
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• pp.71-78
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• 2013

Subcritical water hydrolysis was carried out in a batch reactor to produce valuable materials, such as low-molecular weight (MW) peptides and essential amino acids with antioxidant properties, from heat-dried squid viscera. Hydrolysis of squid viscera was performed at 160 to $280^{\circ}C$ for 3 min. The yield was increased by increasing the temperature and pressure, while the protein content of squid viscera hydrolysate decreased with increasing temperature. Low-MW peptides were detected in all hydrolysates by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The highest yields of free and structural amino acids in heat-dried squid viscera hydrolysate were at $160^{\circ}C$ and were $411.95{\pm}1.15$ and $346.62{\pm}1.25$ mg/100 g, respectively. All essential amino acids were detected in viscera hydrolysates; leucine was the most abundant. Antioxidant activities of hydrolysates were highest at $220^{\circ}C$. Greater than $98{\pm}0.26%$ of the ABTS antioxidant activity was retained in hydrolysates after long-term heat treatment.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.40 no.4
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• pp.16-26
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• 2008

It is of great importance to decrease sheet break at the size press to enhance the runnability of today's high speed paper machines. To achieve this purpose it is required to control the penetration of the starch solutions at the size press. Use of ASA sizing system provides diverse advantages in improving machine runnability since it allows us to get rapid sizing development at the size press. Domestic paper industries, however, has not enjoyed these benefits of ASA sizing system mainly because of the poor efficiency of domestic corn starches used for ASA emulsification. To improve the emulsion stability and ASA sizing efficiency, it has been pointed out that new cationic starches are needed. In this study two methods of starch modifications, i.e. esterfication of cationic corn starch with OSA (Octenyl Succinic Anhydride), and acid hydrolysis by sulfuric acid were employed as methods to improve ASA sizing efficiency. The effect of these modification was compared with conventional cationic starches.

• Bulletin of the Korean Chemical Society
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• v.34 no.5
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• pp.1457-1461
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• 2013

The $Fe_3O_4$-core and Ag-shell ($Fe_3O_4@Ag$ nanoeggs) were prepared through the encapsulation of 3-aminopropyltriethoxysilane-coated magnetite nanoparticle in nano-Ag shell by a simple chemically controlled procedure. The $Fe_3O_4@Ag$ nanoeggs were characterized by scanning electron microscopy, transmission electron microscopy, UV-vis spectrum and superconducting quantum interference device magnetometer, respectively. A detailed analysis is provided of how the hydrolysis and condensation of 3-aminopropyltriethoxysilane and the pH value are vital in fabricating the $Fe_3O_4@Ag$ nanoeggs. The prepared $Fe_3O_4@Ag$ nanoeggs possessed uniform size, improved monodispersity, stability against aggregation and high magnetization, which were utilized for the detection of latent fingerprints deposited onto different surfaces. The experimental results showed that the latent fingerprints developed with the $Fe_3O_4@Ag$ nanoeggs powders exhibited excellent ridge details with minimal background staining.

• Korean journal of food and cookery science
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• v.22 no.3 s.93
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• pp.282-290
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• 2006

This study was carried out to investigate the effects of modified starch, sugars and enzymatic hydrolysis with ${\beta}-amylase$ on extending the self-life of Injulmi, a Korean soft and glutinous rice cake, in terms of maintaining a soft texture. The Injulmi was prepared with or without kneading of waxy rice flour, NaCl and water mixture. The Injulmi was stored at -20, 4 and $20^{\circ}C$ and the hardness was measured to calculate the Avrami exponents during storage. The results showed that cold heading and enzymatic hydrolysis with ${\beta}-amylase$ before steaming of the waxy rice dough significantly extended the self-life on the basis of the Avrami equation. Among the various additives including different kinds of starches, sugars and polymannuronic acid, the addition of 1.5% tapioca starch, 8.0% of glucose or 3.0% of polymannuronic acid was also effective for delaying the retrogradation phenomena during storage. However, despite the effectiveness of these treatments, the Injulmi developed hardness within 2-3 days at $4^{\circ}C$ and within 4 days at $20^{\circ}C$ while storage at $-20^{\circ}C$ showed a storage stability that was maintained over x days. Sensory showed the Injulmi prepared with NOVA-0.005, GL-8.0 had a lower hardness than that of the other treatments.

• Food Science and Biotechnology
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• v.18 no.2
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• pp.488-493
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• 2009

A protein isolate was prepared from black soybean (Glycine max L. Merrill) that possessed higher antioxidant activity than ordinary white soy protein isolates. The isolate was partially hydrolyzed by alcalase to reduce the allergenicity of black soybean. Alcalase remarkably reduced the molecular mass of the major soybean allergens that have molecular weights of 53, 38, and 24 kDa. Hydrolytic breakdown occurred more effectively in Gly m Bd 30K than in Gly m Bd 60K or Gly m Bd 28K. Alcalase hydrolysis increased the solubility and hydrophobicity of the black soybean protein isolate. The foaming activity and stability of black soybean proteins were highly increased by the partial hydrolysis.