• Food Science and Preservation
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• v.17 no.4
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• pp.541-546
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• 2010

Wild-garlic (Allium victorialis L.) is a perennial plant found in worldwide and has been considered as a favorite vegetable due to its particular smell and taste. However, the study of biological activity of wild-garlic and the development of processed food are in rudimentary. In this study, we evaluated several biological activities, including antioxidant, antimicrobial, and inhibitory activities against human thrombin, $\alpha$-amylase and $\alpha$-glucosidase, of Ulrung wild-garlic. Analysis of the composition showed that Ulrung wild-garlic is nutritive although it is perishable. The color of fresh juice was stably maintained during 10 days-storage at $4^{\circ}C$, but rapidly discolored by heat treatment at $70^{\circ}C$ for 1 h. During heat treatment, the contents of total sugar and total polyphenol were decreased to 75% and 50%, respectively, and acidity was increased from 0.069% to 0.111%. In a while, the brix, reducing sugar, and total flavonoids showed minor changes. The fresh juice showed strong DPPH scavenging activity, reducing power and antibacterial and antifungal activity, but the heat-treated juice lost the antioxidant and antimicrobial activities. The inhibitory activities against human thrombin and $\alpha$-amylase and $\alpha$-glucosidase was negligible in both fresh juice and heat-treated juice. These results suggested that the antioxidant and antimicrobial components in wild-garlic are heat-liable and volatile. Based on our results, we propose non-heat treatment products for processed wild-garlic, for example, fresh juice-added beverage or fermented liquors using wild-garlic.

• The Microorganisms and Industry
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• v.19 no.2
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• pp.34-41
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• 1993

Industrial strain improvement is concerned with developing or modifying microorganisms used in production of commercially important fermentation products. The aim is to reduce the production cost by improving productivity of a strain and manipulating specific characteristics such as the ability to utilize cheaper raw materials or resist bacteriophages. The traditional empirical approach to strain improvement is mutation combined with selection and breeding techniques. It is still used by us to improve the productivity of organisms in amino acids, organic acids and enzymes production. The breeding of high L-lysine-producing strain Au112 is one of the outstanding examples of this approach. It is a homoserine auxotroph with AEC, TA double metabolic analogue resistant markers. The yield reaches 100 g/l. Besides, the citric acid-producing organism Aspergillus niger, Co827, its productivity reaches the advanced level in the world, is also the result of a series mutations especially with $^60Co{\gamma}$-radiation. The thermostable .alpha.-amylase producing strain A 4041 is the third example. By combining physical and chemical mutations, the strain A 4041 becomes an asporogenous, catabolite derepressed mutant with rifamycin resistant and methionine, arginine auxotroph markers. The .alpha.-amylase activity reaches 200 units/ml. The fourth successful example of mutation in strain improvement is the glucoamylase-producing strain Aspergillus niger SP56, its enzyme activity is 20,000 units/ml, 4 times of that of the parental strain UV-11. Recently, recombinant DNA approach provides a worthwhile alternative strategy to industrial strain improvement. This technique had been used by us to increase the thermostable .alpha.-amylase production and on some genetic researches.

• Preventive Nutrition and Food Science
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• v.6 no.2
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• pp.101-106
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• 2001

Alpha-amylase and glucoamylase activities were higher in koji with 40% water than that with 30 and 50% water, and A. oryzae exhibited very high alpha-amylase and glucoamylase activities compared to A. sojae and A. niger. Acidic, neutral and alkaline protease activities also showed higher activities in koji prepared with flour, Korean wheat powder and soybean powder with 40% water based on the weight of the sample. Alpha-amylase, acidic, neutral and alkaline protease activities of all the koji samples according to incubation periods increased until 3~4 days of incubation and maintained nearly the same level or slightly decreased after 5 days of incubation. The protease activities of A. oryzae and A. sojae showed nearly the same trend regardless of differences in substrate conditions and koji materials, but those of A. niger showed a lower activity than those of A. oryzae and A. sojae. These results suggest that the preparation of koji is possible with Korean wheat powder and soybean powder and A. sojae can be utilized as a new strain for fermented foods using soybean as the main materials to increase functional properties and produce products having a new taste and flavor.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.5
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• pp.361-367
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• 2002

In order to determine the optimum harvest time for the seed production of inbreds and hybrids in silage corn, the ears of sib-pollinated 'KS5', 'KS7rhm', and 'Ga209' and cross-pollinated 'KS5' $\times$ 'KS6' (Suwon19), 'KS7 rhm' $\times$ 'KSl17' (Suwonok), and 'Ga209' $\times$ 'DB544'(Kwanganok) were harvested at the one-week intervals from 4 to 10 weeks after silking. The optimum harvest time for the seed production for 'KS5', 'KS5' $\times$ 'KS6', 'KS7 rhm', and 'KS7rhm' $\times$ 'KS117' was 7 weeks after silking considering both emergence rate and plumule growth in cold test. Although earlier harvested seeds showed similar germination rate as the seeds harvested at the optimum time at $25^{\circ}C$, their emergence rate were lower in cold test. Seed weight and $\alpha$-amylase activity of earlier harvested seeds were lower compared to those of seeds harvested at the optimum time, while leakage of total sugars and electrolytes were higher. However, the later harvested seeds showed lower germination rates at $25^{\circ}C$ and emergence rates in cold test probably due to the lower $\alpha$-amylase activity although they showed increased seed weight and reduced leakage of total sugars and electrolytes. In contrast, the emergence rate of 'Ga209' and 'Ga209' $\times$ 'DB544' in cold test increased up to 10 weeks after silking probably due to the increased seed weight and $\alpha$-amylase activity and reduced sugar and electrolyte leakages during the germination. The cross-pollinated F$_1$ hybrid seeds showed higher germination and emergence rates at $25^{\circ}C$ and in cold test, and higher plumule growth and $\alpha$-amylase activity compared to those of sib-pollinated inbreds.

• Microbiology and Biotechnology Letters
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• v.16 no.5
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• pp.348-351
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• 1988

The production of extracellular $\alpha$-amylase by Bacillus thuringiensis 19 serotypes was examined by the hydrolysis test of starch. Thirteen serotypes produced the amylase. B. thuringiensis serovar thuringiensis alesti, kurstaki, sotto, kenya, israelensis, morrisoni, entomocidus, tolworthi, thompsoni, toumanoffi, pakistani, and indiana produced tee enzyme. The amylase produced by B. thuringiensis serovar israelensis showed highest activity around pH 6.7 to 7.2 and 55$^{\circ}C$ to $65^{\circ}C$. The high production medium of the amylase was composed of 1% bactopeptone, 0.3% beef-extract, 0.3% yeast ex-tract, 0.5% NaCl, 0.3% $K_2$HPO$_4$, 0.1% KH$_2$PO$_4$, 0.2% Soluble Starch, 0.012% CaCl$_2$.2$H_2O$$_2$, 0.005% MnCl$_2$, and 0.03% MgCl$_2$.7$H_2O$. The highest production of the enzyme was observed at 4 hours culture in the soluble starch (0.6 units/$m\ell$) or glucose (0.43 units/$m\ell$) substrate.

• Journal of Life Science
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• v.24 no.11
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• pp.1224-1230
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• 2014

The red radish (Raphanus sativus L.; RR) sprout is a plant of the cruciferous family. In this study, we elucidated the effect of the water extract of RR sprout (RRSE) against ${\alpha}$-amylase, ${\alpha}$-glucosidase, and pancreatic lipase enzyme activity and adipogenesis in 3T3-L1 preadipocytes. ${\alpha}$-amylase, ${\alpha}$-glucosidase, and pancreatic lipase enzyme activity was inhibited in a concentration-dependent manner by RRSE treatment. RSSE also abolished adipocyte differentiation and lipid and triglyceride accumulation without cytotoxicity in 3T3-L1 adipocytes. In addition, RRSE modulated the expression of the proteins related to adipogenic transcription factors: peroxisome proliferator-activated receptor (PPAR)${\gamma}$, sterol regulatory element-binding protein 1 (SREBP-1), and CCAT/enhancer binding protein (C/EBP)${\alpha}$. RRSE also suppressed expression of the proteins responsible for lipid synthesis, transport, and storage: adiponectin, fatty acid synthesis (FAS), perilipin, and fatty acid bind protein-4 (FABP4). This study showed that RRS treatment has the potential to inhibit obesity by controlling the expression of adipogenic transcription factors and adipogenic proteins.

• Food Science and Preservation
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• v.21 no.4
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• pp.460-467
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• 2014

This study was conducted to investigate the effect of the addition of Hizikia fusiforme, Capsosiphon fulvescens, and Undaria pinnatifida sporophyll on the antioxidant and inhibitory potentials against key enzymes related to type 2 diabetes of a commercial vegetable extract. The nutritional quality and mineral concentration of a vegetable extract with seaweeds added were also analyzed. The addition levels of seaweed did not influence the proximate composition, whereas the calcium, sodium, potassium, magnesium, and iron concentrations significantly increased at the 5% Hizikia fusiforme and Undaria pinnatifida sporophyll addition levels. The 20% Hizikia fusiforme addition level significantly increased the total phenolic content and reducing power by 47.08% and 16.82%. The hydroxyl radical scavenging ability of the vegetable extract was not strengthened with the addition of seaweeds. The DPPH radical scavenging activity at the 20% Hizikia fusiforme, Capsosiphon fulvescens, and Undaria pinnatifida sporophyll addition levels significantly increased by 27.47%, 22.25%, and 17.27%, respectively. The vegetable extract with seaweeds added showed higher-level ${\alpha}$-glucosidase inhibition activities, accompanied by relatively weaker ${\alpha}$-amylase inhibition activity. In particular, at the 5% Undaria pinnatifida sporophyll addition level, the ${\alpha}$-glucosidase activity was significantly inhibited by 98.26%. Overall, the results showed that the incorporation of seaweeds into a vegetable extract effectively increased the mineral concentration and improved the antioxidant and inhibitory abilities of the extract on key enzymes linked to type 2 diabetes.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.6
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• pp.577-583
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• 2001

The digestive enzyme activities such as $\alpha-amylase$, trypsin and pepsin from the laboratory-reared river puffer Takifugu obscurus were measured from the time course of 1 day until the 65 day after hatching. In the case of $\alpha-amylase$, it was showed minimum activity of 0.0493 U/mg at the total length (TL) 10 mm, and showed maximum activity of 0.1480 U/mg at 19 mmTL. Trypsin and pepsin were showed their maximum activities of 0.0264, 0.0258 U/mg and 0.0178, 0.0201 U/mg when the total length of 16 and 24 mm, and represented remarkable correlations between the changes of enzyme activity and growth rate. The ontogenetic variations of digestive enzymes were represented clearly different patterns; i.e, the pepsin showed higher activity when the periods of larva ($4\~5\;mmTL$) and juvenile II ($19\~24\;mmTL$), however, the trypsin represented maximum activity at the stages of juvenile I ($11\~16\;mmTL$) and young fish (27 mmTL), respectively.

• Applied Biological Chemistry
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• v.21 no.2
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• pp.84-102
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• 1978

Barley embryoless half seeds were incubated in medium containing $10{\mu}M$ GA. Time course activity changes of ${\alpha}-amylase$ were studied in extract and medium seperately by the addition of $0.1{\mu}M,\;5{\mu}M,\;and\;10{\mu}M$ ABA in midcourse incubation of 10 hours after GA treatment. MAK profiles of nucleic acids in embryoless half seeds were compared either with $10{\mu}M$ GA treatment or concomitant treatment with $10{\mu}M$ GA and $10{\mu}M$ ABA after 10 hours incubation, Time course changes of weight increase, chlorophyll, protein and RNA consent in addition to RNase activity were studied in the presence of $10{\mu}M$ GA or $10{\mu}M$ ABA in barley coleoptile sections. After 20 hours incubation in the presence of plant hormones, MAK profiles of nucleic acids and reactive distribution of polysome and monosome were investigated. The above results were summarized as follows. 1) The production of ${\alpha}-amylase$ by treatment with GA alone increased at a linear rate in the incubation period and the active secretion of ${\alpha}-amylase$ began from 18 hours incubation in embryoless half seeds. 2) On the contrary to the partial inhibition by addition of $0.1{\mu}M$ ABA, the production of ${\alpha}-amylase$ was completely inhibited by both $5{\mu}M$ and $10{\mu}M$ ABA within 4 hours. Regardless of concentration of GA, the addition of $5{\mu}M$ ABA in midcourse completely inhibited the production of ${\alpha}-amylase$ 3) ABA treatment gave no effect on the secretion of ${\alpha}-amylase$. 4) There were no differences in RNA fractions between GA treatment and concomitant treatment with GA and ABA in the barlye embryoless half seeds. 5) While GA treatment increased the r-RNA fraction, ABA treatment decreased it and increased the s-RNA fraction in the coleoptile sections. 6) GA treatment increased RNA-DNA fraction best ABA treatment decreased it in the coleoptile sections. 7) While GA treatment suppressed RNase activity, ABA treatment increased it in the coleoptile sections. 8) GA treatment gave no great effect on the total RNA but ABA treatment remarkably diminished it in the coleoptile sections. 9) While GA treatment increased the growth and chlorophyll content, ABA treatment decreased them in the coleoptile sections. 10) GA treatment increased the protein synthesis and polysome formation but ABA treatment decreased them in the coleoptile sections. 11) The inhibition effect of ABA on polysome formation seemed to be resulted from the inhibition of r-RNA synthesis by ABA.

• Microbiology and Biotechnology Letters
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• v.4 no.3
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• pp.91-97
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• 1976

During the course of studies on the production and utilization of thermostable ${\alpha}$-amylase from a thormophilic actinomycete species isolated from soil, partial characterization of the ${\alpha}$-amylase has been (arried out. The optimum pH for the dextrinogenic activity of the enzyme was found to be 6.5 and the maximum reaction rate was achieved at a temperature range of 55$^{\circ}$ to 65$^{\circ}C$. Calcium ion was recognized to have a slight effect in activating the enzyme, while heavy metal salts especially ferrous and cupric ions showed a remarkable inhibition effect. The enzyme was best protected iron thermal denaturation at pH 8.0 with tris-HCI buffer；inactivation was rapid at higher or lower pH values. Furthermore, its thermal stability was greatly increased by calcium ion, particulary at the final concentration of 1${\times}$10$\^$－2/ mole in the reaction mixture. The Km value for the ${\alpha}$-amylase was calculated to be 2.17${\times}$10$\^$－4/g per $m\ell$ and the energy of activation for the dextrinogenic reaction to be 12,000${\pm}$580 ㎈ per mole.