• Food Science and Biotechnology
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• v.17 no.1
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• pp.130-134
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• 2008

Hypoglycemic effect of onion skin extract in vitro and in vivo was investigated. A methanol extract of onion skin inhibited yeast $\alpha$-glucosidase with an $IC_{50}$ of 0.159 mg/mL. A single oral administration of the onion skin extract (500 mg/kg) significantly lowered the postprandial area under the glucose response curve to starch (1 g/kg, p<0.05). Three-week-old db/db mice were fed an AIN-93G diet or a diet supplemented with a 0.5% onion skin extract for 7 weeks after a 1-week adaptation period. Consumption of onion skin extract significantly reduced the levels of plasma glucose, insulin, and blood glycated hemoglobin as compared with the control group (p<0.05). These findings suggest that onion skin is effective in controlling hyperglycemia in animal models of type 2 diabetes mellitus, at least in part by inhibiting $\alpha$-glucosidase activity.

• Food Science and Biotechnology
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• v.17 no.3
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• pp.519-526
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• 2008

To improve the quality of traditional kochujang, strains with high protease and amylase activity were isolated and identified from Sunchang traditional kochujang. Twenty-three strains strongly producing protease and 16 strains strongly producing $\alpha$- and $\beta$-amylase were isolated by using 1% isolated soy protein agar medium and 2% starch agar medium, respectively. Protease activities of the IA7, I5, and IA2 strain were 22.5, 21.2, and 20.6 unit/mL, respectively, and were higher than those of the other strains. Stains with high $\alpha$-amylase activity included K9 (967.8 unit/mL), K14 (828.3 unit/mL), K13 (662.5 unit/mL), K8 (601.5 unit/mL), and K11 (405.9 unit/mL). The $\beta$-amylase activity of the K11 strain was the highest, 34.3 unit/mL, among the isolated strains. Based on morphological, physiological properties, and API 50CHB-kit test for assimilation of 49 carbohydrates, 8 strains selected according to protease, $\alpha$-amylase, and $\beta$-amylase activities were tentatively identified as Bacillus megaterium (IA2), Bacillus subtilis (IA7, 15), Bacillus amyloliquefaciens (K8, K9, K11, and K13), and Bacillus stearothermophillus (K14). The IA7, 15, and K11 strains were finally identified as B. subtilis (99% ID) based on 16S rDNA sequencing.

• Nutrition Research and Practice
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• v.7 no.3
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• pp.166-171
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• 2013

The purpose of this study was to investigate the effects of lotus leaf on hyperglycemia and dyslipidemia in animal model of diabetes. Inhibitory activity of ethanol extract of lotus leaf against yeast ${\alpha}$-glucosidase was measured in vitro. The effect of lotus leaf on the postprandial increase in blood glucose levels was assessed in streptozotocin-induced diabetic rats. A starch solution (1 g/kg) with and without lotus leaf extract (500 mg/kg) was administered to the rats after an overnight fast, and postprandial plasma glucose levels were monitored. Four-week-old db/db mice were fed a basal diet or a diet containing 1% lotus leaf extract for 7 weeks after 1 week of acclimation to study the chronic effect of lotus leaf. After sacrifice, plasma glucose, insulin, triglycerides (TG), total cholesterol (CHOL), high-density lipoprotein (HDL)-CHOL, and blood glycated hemoglobin levels were measured. Lotus leaf extract inhibited ${\alpha}$-glucosidase activity by 37.9%, which was 1.3 times stronger than inhibition by acarbose at a concentration of 0.5 mg/mL in vitro. Oral administration of lotus leaf extract significantly decreased the area under the glucose response curve by 35.1% compared with that in the control group (P < 0.01). Chronic feeding of lotus leaf extract significantly lowered plasma glucose and blood glycated hemoglobin compared with those in the control group. Lotus leaf extract significantly reduced plasma TG and total CHOL and elevated HDL-CHOL levels compared with those in the control group. Therefore, we conclude that lotus leaf is effective for controlling hyperglycemia and dyslipidemia in an animal model of diabetes mellitus.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.3
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• pp.170-174
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• 2005

Barley plants growing in the wet paddy field easily encounter suboptimal oxygen concentration in the rhizosphere that causes molecular oxygen deficiency in root cells. The capacity of root cells to utilize energy sources is known to be positively related to resistance to hypoxia stress. This study was conducted to investigate effects of hypoxia on enzymes involved in the starch and sucrose metabolism. Barley seedlings at the third leaf stage were subjected to hypoxia (1 ppm dissolved oxygen) by purging the culture solution with nitrogen gas for up to seven days. The protein content was slightly decreased by hypoxia for 7 days. $\alpha-Amylase$ activities increased significantly in the root but not in the shoot after 3 to 7 days of hypoxia. $\beta-Amylase$ activities were not affected significantly in both tissues. Additionally, sucrose synthase activities were affected little in both tissues by 7 days of hypoxia. The results indicate that root cells activate break­down of polysaccharide reserves in response to an acute hypoxia to supply energy sources for fermentative glycolysis and cell wall fortification.

• Korean Journal of Food Science and Technology
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• v.41 no.5
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• pp.509-514
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• 2009

The effectiveness of a technique for binding rice-washed solution with trimethylamine (TMA) was investigated in this study. The mixtures of TMA and rice-washed solution were quantified using an electronic nose based on the mass spectrometer. After 7 min of reaction in a model system, the binding of TMA to the rice-washed solution was detected. As the concentration of rice-washed solution increased, the levels of TMA detected in the headspace decreased, thereby indicating an increase in the binding of TMA to the rice-washed solution. The binding effect of the rice-washed solution was comparable to those of starch, ${\alpha}$-cyclodextrin, or amylose, and superior to that of flour. The results of this study demonstrate the potential for reduction of off-flavors using the rice-washed solution.

• Asian-Australasian Journal of Animal Sciences
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• v.8 no.2
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• pp.187-194
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• 1995

Genetic variants of ${\alpha}s_1$-casein, ${\beta}$-casein, ${\kappa}$-casein and ${\beta}$-lactoglobulin were investigated by starch urea gel electrophoresis in milk samples of 280 Korean native cattle. A new ${\beta}$-casein variant, designated ${\beta}$-casein $A^4$, was found in milk samples of Korean native cattle. It has a much slower electrophoretic mobility than the ${\beta}$-casein $A^3$ variant in acid gel. This new variant appeared together with either ${\beta}$-casein $A^1$, $A^2$ or B variant. Gene frequencies and genotypic frequencies were estimated. Gene frequencies of four milk protein loci in Korean native cattle were compared with those of imported cattle breeds raised in Korea and Japanese brown cattle. Gene frequencies were ${\alpha}s_1$-casein B .846, ${\alpha}s_1$-casein C .154; ${\beta}$-casein $A^1$ .216, ${\beta}$-casein $A^2$ .666, ${\beta}$-casein $A^4$ .048, ${\beta}$-casein B .070; ${\kappa}$-casein A .648, ${\kappa}$-casein B .352; ${\beta}$-lactoglobulin A .148, ${\beta}$-lactoglobulin B .852. The population was in Hardy-Weinberg equilibrium at all milk protein loci. Gene frequencies of Korean native cattle were very similar to those of Japanese brown cattle. Interestingly, a new variant, ${\beta}$-casein $A^4$, was found only in Korean native cattle and Japanese brown cattle. These results support the hypothesis that Korean native cattle were used in the development of the Japanese brown cattle.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.2
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• pp.285-294
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• 1992

Biochemical polymorphisms of sow's milk proteins, $\beta$-casein ($\beta$-CN), $\beta$-lactoglobulin ($\beta$-LG), post-lactoglobulin (post-LG), $\alpha$-lactalbumin ($\alpha$-LA) and X-protein, as genetic markers for major pig breeds (Landrace, Yorkshire, Duroc, Hampshire and cross bred) in Korea were determined by starch gel electrophoresis. Phenotype and gene frequencies at all marker loci were estimated and genetic differences among breed populations were analyzed. Three $\beta$-CN phenotypes (AA, AB and BB) controlled by two codominant alleles (${\beta}-CN^A$ and ${\beta}-CN^B$), four $\beta$-LG phenotypes (AA, AC, $AC^{\pm}$ and CC) controlled by two codominant alleles (${\beta}-LG^A$ and ${\beta}-LG^C$) and ten X-protein phenotypes (AA, BB, CC, DD, AB, AC, AD, BC, BD and CD) controlled by four codominant alleles ($X^A,\;X^B,\;X^C\;and\;X^D$) were identified. In addition, a genetically controlled polymorphism of post-LG was found for the first time in sow's milk protein. Three different phenotypes (AA, AB and BB) were designated $post-LG^A$ and $post-LG^B$. Of the five marker loci examined, $\alpha$-LA locus was observed to lack any individual variation in all breeds studied. All populations were in Hardy-Weinberg equilibrium for all loci. There were marked breed differences for phenotype and gene frequencies in the post-LG and X-protein marker loci. However, there were little differences between breeds in the gene frequencies at the $\beta$-CN and $\beta$-LG marker loci.

• Journal of Microbiology and Biotechnology
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• v.20 no.11
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• pp.1539-1545
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• 2010

In beer, glutathione works as the main antioxidant compound, which also correlates with the stability of the beer flavor. In addition, high residual sugars in beer contribute to major nonvolatile components, which are reflected in a high caloric content. Therefore, in this study, the Saccharomyces cerevisiae GSH1 gene encoding glutamylcysteine synthetase and the Saccharomycopsis fibuligera ALP1 gene encoding ${\alpha}$-amylase were coexpressed in industrial brewing yeast strain Y31 targeting the ${\alpha}$-acetolactate synthase (AHAS) gene (ILV2) and alcohol dehydrogenase gene (ADH2), resulting in the new recombinant strain TY3. The glutathione content in the fermentation broth of TY3 increased to 43.83 mg/l as compared with 33.34 mg/l in the fermentation broth of Y31. The recombinant strain showed a high ${\alpha}$-amylase activity and utilized more than 46% of the starch as the sole carbon source after 5 days. European Brewery Convention tube fermentation tests comparing the fermentation broths of TY3 and Y31 showed that the flavor stability index for TY3 was 1.3-fold higher, whereas its residual sugar concentration was 76.8% lower. Owing to the interruption of the ILV2 gene and ADH2 gene, the contents of diacetyl and acetaldehyde as off-flavor compounds were reduced by 56.93% and 31.25%, respectively, when compared with the contents in the Y31 fermentation broth. In addition, since no drug-resistant genes were introduced to the new recombinant strain, it should be more suitable for use in the beer industry, owing to its better flavor stability and other beneficial characteristics.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.43 no.4
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• pp.329-335
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• 2017

We have studied on the keratinocytes differentiation and skin barrier function using Adenophorae radix (A. radix) root extract, which was known to contain triterpenoid, saponin and starch. A. radix root extracts showed the $PPAR{\alpha}$ expression level of Wy-14,643 $0.5-1.0{\mu}M$ in CV-1 cells. The cornified envelop formation (CE) of human keratinocyte cell line (HaCaT) and normal human keratinocyte (NHK) showed a statistically significant increased compared to the control. When HaCaT cells were treated with A. radix root extract, transglutaminase (TGase-1) was significantly increased. As a result of clinical study of the simple cosmetic formulation containing A. radix root extract for about 2 weeks, TEWL values were significantly decreased and water contents were increased. The ceramides, which were obtained from the inner forearm, were also significantly increased statistically. We suggest that the A. radix root extract can be used as a preventive and therapeutic agent for skin diseases such as dry skin and atopy.

• Journal of Microbiology and Biotechnology
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• v.17 no.5
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• pp.792-799
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• 2007

A gene encoding a putative glycogen-debranching enzyme in Sulfolobus shibatae(abbreviated as SSGDE) was cloned and expressed in Escherichia coli. The recombinant enzyme was purified to homogeneity by heat treatment and Ni-NTA affinity chromatography. The recombinant SSGDE was extremely thermostable, with an optimal temperature at $85^{\circ}C$. The enzyme had an optimum pH of 5.5 and was highly stable from pH 4.5 to 6.5. The substrate specificity of SSGDE suggested that it possesses characteristics of both amylo-1,6-glucosidase and $\alpha$-1,4-glucanotransferase. SSGDE clearly hydrolyzed pullulan to maltotriose, and $6-O-\alpha-maltosyl-\beta-cyclodextrin(G2-\beta-CD)$ to maltose and $\beta$-cyclodextrin. At the same time, SSGDE transferred maltooligosyl residues to the maltooligosaccharides employed, and maltosyl residues to $G2-\beta-CD$. The enzyme preferentially hydrolyzed amylopectin, followed in a decreasing order by glycogen, pullulan, and amylose. Therefore, the present results suggest that the glycogen-debranching enzyme from S. shibatae may have industrial application for the efficient debranching and modification of starch to dextrins at a high temperature.