• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.9
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• pp.1321-1327
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• 2011

The microorganism producing an invertase (E.C. 3.2.1.26) was isolated from wine and tentatively identified as Saccharomyces cerevisiae by cellular fatty acid analysis. The invertase was purified to homogeneity by ammonium sulfate precipitant, dialysis, ion-exchange chromatography on DEAE-Sephadex A-50, and gel chromatography on Sephadex G-200 from the culture supernatant of Saccharomyces cerevisiae JS59. The specific activity and the purification fold of the purified invertase were 7620.9 unit/mg protein and 13.9, respectively. The molecular weight of the purified invertase was estimated to be 38.5 kDa by SDS-PAGE. The optimum pH and temperature for the invertase activity were pH 5 and $55^{\circ}C$, respectively. The invertase activity was relatively stable at pH 4~6 and temperature $55^{\circ}C$. The activity of invertase was inhibited by $Ag^{2+}$ and $Hg^{2+}$, but on the contrary, activated by $Co^{2+}$ and $Mn^{2+}$. Michaelis constant ($K_m$) for invertase reaction in sucrose solution was 11.5 mM. TLC analysis of the products produced in sucrose solution during invertase reaction showed the progressive presence of glucose and fructose in accordance with sucrose hydrolysis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.3
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• pp.11-20
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• 1987

The study was carried out to observe some fundamental effect of spices on tenderization of beef, particularly round muscle part. The study has been investigated analytically in terms of histological and sensory test to compare the tenderizing effect of the spices with respective effect of commercial meat tenderizer and mechanical tenderizer on beef. The results of formal titration assay using casein as a substrate were that garlic, radish and ginger were stronger in protein hydrolysis than the other spices. Beef with spice treatment produced partial degradation of muscle fiber and connective tissue. Connective tissues and muscle fiber were generally degraded conspicuously by the treatment of commercial meat tenderizer. A general disruption and severing of muscle fibers and severing of connective tissue were seen in the area of blade penetration. The results of sensory test on the texture were that F-value of 11.27 is significant at the 1% of the sample. Beef treated with spices was significantly tenderer than beef without treatment at 5% level.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.3
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• pp.261-268
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• 2008

To utilize Cheonggukjang as a raw material of diverse foods, the quality characteristics of Cheonggukjang and its processed food were compared. Cheonggukjang (CGJ), red ginseng Cheonggukjang (RCJ), and red ginseng Cheonggukjang hydrolysate (RCH) were powdered, and their quality and functional characteristics were examined. The result showed that in regard to general components, carbohydrate content of RCJ was higher than other samples while crude protein content was lower. Free amino acid content of RCH was 2,157.16 mg%, which was approximately 2 times higher than CGJ, and the content of essential amino acid was 812.18 mg%, which was the highest. The result of SDS-electrophoresis pattern showed that CGJ and RCJ showed a molecular weight smaller than 33 kDa, and RCH showed a smaller than 17 kDa low molecular weight, confirming the hydrolysis to small molecular weight. Among the samples, free radical scavenging activity, superoxide radical scavenging activity, and ACE inhibitory activity did not show a significant difference; nonetheless, RCH showed the highest activity while CGJ showed the highest fibrinolytic activity of 111.38 unit. In addition, in sensory evaluation, the peculiar bitter taste of red ginseng could be detected while the overall acceptability was improved. Based on the above results, in comparison with CGJ, as for RCJ and RCH, their function was strengthened and unpleasant odor was reduced, and thus it is anticipated that they could be used as a raw material of diverse foods.

• Korean Journal of Agricultural Science
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• v.47 no.3
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• pp.459-470
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• 2020

This study investigated the effects of the proteolytic hydrolysates of α-lactalbumin (LA), β-lactoglobulin (LG) and bovine serum albumin (BSA) by alcalase on inflammatory cytokines. The proteolytic hydrolysates were separated into two fraction of peptides, ≤ 10,000 Da and > 10,000 Da, respectively, because various low molecular weight peptides were generated during the hydrolysis reaction time. Among the hydrolysate peptides, BSA (all types), β-LG (> 10,000 Da), and α-LA (> 10,000 Da) showed an inhibitory activity against thymic stromal lymphopoietin (TSLP) mRNA expression in lipopolysaccharide-induced RAW264.7 murine macrophages. α-LA (> 10,000 Da), β-LG (hydrolysates), and BSA (> 10,000 Da) showed an inhibitory activity against tumor necrosis factor (TNF)-α expression. α-LA (all types), β-LG (hydrolysates, > 10,000 Da), and BSA (> 10,000 Da) showed an inhibitory activity against interleukin-6 (IL-6) expression. α-LA (> 10,000 Da), β-LG (> 10,000 Da), and BSA (all types) showed an inhibitory activity against inducible nitric oxide synthase (iNOS) expression. α-LA (> 10,000 Da), β-LG (> 10,000 Da), and BSA (all types) showed an inhibitory activity against cyclooxygenase (COX)-2 expression. The lowest level of TNF-α production was measured with α-LA (> 10,000 Da) and β-LG (> 10,000 Da) for all types, and a similar low level was measured for all types of BSA. The highest level of IL- 6 production was measured with α-LA (≤ 10,000 Da) among α-LA, β-LG, and IL-6. The low level of NO production was similar with α-LA, β-LG, and BSA but not with α-LA (≤ 10,000 Da). These potential peptides from whey protein hydrolysates could be used for food, medicinal, and industrial applications.

• Journal of Life Science
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• v.17 no.10
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• pp.1341-1346
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• 2007

An intracellular ${\beta}-xylosidase$ from Paenibacillus sp. DG-22 was purified to homogeneity by ion-exchange, hydrophobic interaction and gel-filtration chromatography. The molecular weight of the enzyme was measured to be 156,000 by gel filtration and 80,000 by SDS-PAGE, indicating that the enzyme consisted of two identical subunits. The purified enzyme exhibited maximum activity at $65^{\circ}C$ and pH 5.5. It retained 89% of its initial activity up to 60 min at $60^{\circ}C$ and had a half-life of 25 min at $65^{\circ}C$. The enzyme was highly specific for pNPX as the substrate. It showed little or no activity against other p-nitrophenyl glycosides and xylans. The $K_m\;and\;V_{max}$ for pNPX was 0.53 mM and 3.18 U/mg protein, respectively. The ${\beta}-xylosidase$ was strongly inhibited by $Ag^+,\;Fe^{2+},\;Hg^{2+}\;and\;Zn^{2+}$ and slightly activated by DTT. The hydrolysis product from xylobiose, xylotriose, and xylotetraose was xylose.

• The Korean Journal of Mycology
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• v.22 no.3
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• pp.266-275
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• 1994

Brewer's yeast extract can be used as a good substrate for the culture of Lentinula edodes Mycelia(LEM). We found that it was better to filter the extract through three kinds of sieves and then to heat for hydrolysis and concentration at $90^{\circ}C$ prior to use. Also the maximum condition for the growth of LEM was investigated. We found that addition of inorganic salts such as calcium enhanced the growth of LEM. On the other hand, addition of carbon and nitrogen sources to the medium did not affect, and even inhibited under certain conditions, the growth of LEM. The maximum temperature for the growth of LEM was around $25^{\circ}C$. Also, it grows better when agitated by shaking at 100 rpm for airration. The appropriate concentration of the extract to use was 10%. Under these conditions, LEM could reach to the confluency after cultivation of 12 days. Our extract formula seems better than other available media for LEM growth, producing higher crude protein content and better taste.

• Journal of Microbiology and Biotechnology
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• v.26 no.6
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• pp.1115-1123
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• 2016

_L-Asparaginase (E.C. 3.5.1.1) is an enzyme involved in asparagine hydrolysis and has the potential to effect leukemic cells and various other cancer cells. We identified the _L-asparaginase gene (_L-ASPG86) in the genus Mesoflavibacter, which consists of a 1,035 bp open reading frame encoding 344 amino acids. Following phylogenetic analysis, the deduced amino acid sequence of _L-ASPG86 (_L-ASPG86) was grouped as a type I asparaginase with respective homologs in Escherichia coli and Yersinia pseudotuberculosis. The _L-ASPG86 gene was cloned into the pET-16b vector to express the respective protein in E. coli BL21 (DE3) cells. Recombinant _L-asparaginase (r-_L-ASPG86) showed optimum conditions at 37-40℃, pH 9. Moreover, r-_L-ASPG86 did not exhibit glutaminase activity. In the metal ions test, its enzymatic activity was highly improved upon addition of 5 mM manganese (3.97-fold) and magnesium (3.35-fold) compared with the untreated control. The specific activity of r-_L-ASPG86 was 687.1 units/mg under optimum conditions (37℃, pH 9, and 5 mM MnSO₄).

• Journal of Animal Science and Technology
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• v.49 no.4
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• pp.531-538
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• 2007

A total of 127 Korean native black pigs(gilt 30, boar 97) were used to investigate the carcass properties, yields of retail cut and meat quality. The average live weight, chilled carcass percentage and retail cut percentage used in this study were 74.69kg, 71.14% and 61.09% for boar, and 75.5kg, 73.88% and 56.25% for gilt, respectively. Although gilts were higher in live weight and chilled carcass percentage whereas lower in retail cut percentage when compared to boars, there was no significantly difference between gender(p<0.05). Gilts had higher fat contents than boars regardless of weight range groups. Protein contents increased as slaughter weight increased for gilt and boar groups. Gilts contained high intramuscular fat contents had significantly lower Warner-Bratzler shear force(WBS) and water holding capacity(WHC) when compared to boar in the same weight range group(p<0.05). There was no significantly different in meat color(p>0.05) although gilts had higher L(lightness), a(redness) and b(yellowness) values when compared to the same group of boar. From the result of this study can be used for the grading guideline and quality evaluation standard of Korean native black pigs by gender and live weight.

• Korean Journal of Microbiology
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• v.53 no.4
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• pp.257-264
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• 2017

Pseudomonas veronii MS1 and P. migulae MS2 have several mechanisms of copper resistance and plant growth promoting capability, and also can alleviate abiotic stress in plant by hydrolysis of a precursor of stress ethylene, 1-aminocyclopropane-1-carboxylic acid (ACC) by ACC deaminase. In 4-week pot test for tomato growth in soil contained 700 mg/kg Cu, inoculation of MS1 and MS2 significantly increased root and shoot lengths, wet weight and dry weight of tomato plants compared to those of uninoculated control. The inoculated tomato plants contained less amounts of proline that can protect plants from abiotic stress, and malondialdehyde, an oxidative stress marker than those of control. ACC synthase genes, ACS4 and ACS6, and ACC oxidase genes, ACO1 and ACO4, both involved in ethylene synthesis, were strongly expressed in Cu stressed tomato, whereas significantly reduced in tomato inoculated with MS1 and MS2. Also, a gene encoding a metal binding protein metallothionein, MT2 showed similar expression pattern with above genes. All these results indicated that these rhizobacteria could confer Cu resistance to tomato plant under Cu stress and allowed a lower level of Cu stress and growth promotion.

• Food Science and Preservation
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• v.24 no.3
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• pp.455-463
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• 2017

In this study, the biological activities and physicochemical properties of polysaccharides from Gloiopeltis furcata were investigated. Polysaccharides were isolated by enzymes treatment (celluclast, flavourzyme, papain, termamyl, viscozyme) followed by ethanol precipitation and lyophilization. The yield of polysaccharides by enzymes treatment group were 52.8-66.4%. The major constituents in viscozyme treatment group were total sugar (71.04%), protein (7.22%), uronic acid (23.18 g/100 g), and sulfate (28.27%), respectively. The DPPH radical scavenging activity and ferric reducing antioxidant potential of the viscozyme treatment group at 5 mg/mL were 23.10% and $218.50{\mu}M$, respectively. The protective effects against $H_2O_2$-induced cytotoxicity in L132 cell of viscozyme treatment group at $1{\mu}g/mL$ was 85.64%. The viscozyme treatment group increased the production of nitric oxide (NO) in a dose-dependent manner. The antitumor activity of viscozyme treatment group (at $25{\mu}g/mL$) in A549, HeLa, SNU719 and MCF7 was 69.57%, 52.74%, 61.06% and 68.64%, respectively. All of data showed that the biological activities and chemical characteristics of enzymes treatment group are higher than that of the control group. The polysaccharides isolated from Gloiopeltis furcata investigated herein are useful as functional materials agents.