• Korean Journal of Agricultural Science
• /
• v.24 no.2
• /
• pp.283-289
• /
• 1997

CNU O4-5 isolated from conventional Meju, which is used as raw material for making a soybean fermentation food, identified as an Aspergillus oryzae. To make koji, Aspergillus oryzae CNU O4-5 was cultured for 3-4 days at $30^{\circ}C$ with various grain materials such as flour, soybean powder, flour+soybean powder(1:1), soaked soybean and rice. The koji was evaluated for analyze the angiotesin converting enzyne(ACE) inhibition, antioxidative activity, superoxide dismutase(SOD) activity, amylase and protease activity. $\alpha$-amylase and glucoamylase activities of flour koji were higher than those of the koji soybean powder. However neutral and alkaline protease activities of flour koji were lower than those of flour+soybean powder and soybean koji. Amylase and protease activities of kojies of soaked soybean and rice showed very low level. The range of the ACE inhibition rate by hot water fraction of the kojies, which are cultured with various gain materials, were from 45% to 54%. The anti oxidative activity of ethanol-fraction of koji, which is made by using the soybean powder or soaked soybean, prolonged for 6 days in lard at $60^{\circ}C$. The SOD activity of grinded fraction of koji, which is made by using the flour or soybean powder, was same as 2,000 units per g of each koji.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.40 no.8
• /
• pp.1150-1156
• /
• 2011

Deoduk (Codonopsis lanceolata) root powder was added to traditional kochujang to improve the quality of traditional kochujang. The microbial characteristics, enzyme activities, and sensory characteristics were investigated during fermentation. The aerobic bacterial count in kochujang was not remarkabley different, and yeast and mold decreased during fermentation. Yeast and mold in the kochujang with 3 and 5% added deoduk root powder were 5 log scale at 8 weeks, whereas those in the control reached the same level at 6 weeks. ${\alpha}$, ${\beta}$-Amylase activity was at its highest level at 4 weeks during fermentation, and glucose and fructose contents showed the same results. The major free sugars in kochujang were glucose and fructose, and their contents increased rapidly at 2 weeks. Free sugar contents of kochujang with added deoduk was higher than that in the control. The sensory evaluation results showed that 1 and 3% deoduk kochujang had higher scores for taste and overall acceptance than those in the control. In particular, 1% deoduk kochujang had the highest scores.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.37 no.3
• /
• pp.276-281
• /
• 2008

Extracts from Rododendron mucronulatum Turcz. flowers were tested for antioxidant and their inhibitory activities of ${\alpha}$-amylase, ${\alpha}$-glucosidase and angiotensin converting enzyme (ACE). Total contents of phenolics were found as $30.6{\pm}0.14mg/g$ (60% EtOH extract) and $23.2{\pm}0.21mg/g$ (water extract). Electron donation ability (EDA), ABTS [2,2azinobis(3-ethylbenzothiazoline-6-sulfonic acid)] radical decolorization, Antioxidant protection factor (PF) and thiobarbituric acid reactive substance (TBARs) were measured for the antioxidative activity of the extracts from Rododendron mucronulatum Turcz. flowers. The water extract were determined as 97.5% at ethanol extract showed 83.2% and 60% EtOH extract were 89.7% in EDA. The water extract showed higher antioxidant activity than 60% EtOH extract when evaluated by ABTS radical decolorization and antioxidant PF. The TBARS of water extracts and 60% EtOH extracts were shown as $0.29{\times}10^2{\mu}M\;and\;0.28{\times}10^2{\mu}M$, respectively, and were lower than control. ACE inhibitory activity in water extract (67.6% inhibition) was higher than that of 60% EtOH extract (46.7% inhibition) at $200{\mu}g/mL$. Water extracts had higher inhibitory activities on ${\alpha}$-amylase and ${\alpha}$-glucosidase than 60% EtOH extracts. The result suggests that the water extract from Rododendron mucronulatum Turcz. flowers will be useful as natural antioxidants and functional foods.

• Microbiology and Biotechnology Letters
• /
• v.24 no.5
• /
• pp.604-612
• /
• 1996

To improve the fermentation characteristics of the haploid starch-fermenting recombinant yeast strain K114/YIpMS$\Delta$R(LEU2/URA3) secreting both $\alpha$-amylase and glucoamylase was rare-mated with polyploid industrial yeast Saccharomyces sp. K35. The K35 strain had good fermentation-characteristics such as ethanol-tolerance, high temperature and sugar-tolerance, and high fermentation rate. Among the resulting 66 hybrids, the best strain RH51 was selected. The RH51 exhibited amylolytic activity of K114/YIpMS$\Delta$R(LEU2/URA3) as well as ethanol and sugar tolerance of K35. The optimum temperature of hybrid RH51 for starch fermentation was 34$\circ$C which was same as that of K35 but different from that (30$\circ$C) of K114/YIpMS$\Delta$R(LEU2/URA3). The optimum pH was 5.0. The optimum size of inoculum was 2% as the pellet (w/v) of yeast cells. The hybrid strain RH51 produced 7.0% ethanol (w/v) from 20% (w/v) soluble starch while K35 formed almost no ethanol, 0.3% (w/v). RH51 strain produced 7.5% (w/v) ethanol after 8 days in a 2.5 l fermenter containing 800 ml of 20% (w/v) soluble starch. The residual starch content in the fermentation medium was 1.68% (w/v), and therefore almost all the starch was fermented completely.

• Journal of Microbiology and Biotechnology
• /
• v.6 no.4
• /
• pp.270-277
• /
• 1996

A bacteriocin-producing strain, DU-0608, was isolated from Kimchi and identified as Leuconostoc mesenteroides subsp. mesenteroides. The bacteriocin from isolate was inhibitory against Listeria monocytogenes, Micrococcus luteus and several strains of lactic acid bacteria. The bacteriocin was inactivated by pepsin, trypsin, $\alpha$-chymotrypsin, protease, $\alpha$-amylase and lipase, but not by catalase or by heating at $100^{\circ}C$ for 60 min. The molecular weight of the bacteriocin was estimated approximately 6 kDa. The inhibitory effect was bactericidal and rapid. Following treatment with isolate bacteriocin, cells of indicator strain (Lactobacillus sake JCM 1157) were damaged at the end regions of the cell wall, whereas the cells treated with nisin were damaged at many places around the cell wall.

• Applied Biological Chemistry
• /
• v.47 no.2
• /
• pp.176-181
• /
• 2004

This study was carried out to investigate the effect of yucca extract on the quality characteristics of Chungkookjang using Bacillus subtilis p01. The changes in the contents of amino-type N, ammonia type N, volatile compounds and organic acids, and those in the activities of ${\alpha}-amylase$ and protease were also determined during aging of Chungkookjang. The amount of amino-type N increased gradually with time for aging. The content of amino-type N was slightly higher in Chungkookjang fermented by adding yucca extract than in the control without yucca extract. The content of ammonia-type N was slightly lower in Chungkookjang with yucca extract than in the control without yucca extract. The activities of amylase and protease were higher in Chungkookjang with yucca extract than in the control and the highest in Chungkookjang containing 0.5 mg/g of yucca extract. Organic acid contents in Chungkookjang was the highest at the initial period of fermentation. The contents of organic acids in Chungkookjang with yucca extract was higher than that in control for 48 hr of aging. The amounts of 2,5-dimethylpyrazine were increased by addition of yucca extract, while those of cis-3-hexanol were decreased.

• Journal of Ginseng Research
• /
• v.31 no.4
• /
• pp.203-209
• /
• 2007

This study examined the extraction yields, total phenolic compounds content and the antioxidant activities on V79-4 cells of white ginseng extracts prepared by enzyme treatment. Yields of crude extract were 29.5-76%, and total phenolic compounds content showed 0.45-2.2% according to enzyme treatments. Pectinase treatment group showed the highest values of extraction yields and total phenolic compounds content. Pectinase and a-amylase treatment groups protected V79-4 cell viability(above 50%) against $H_2O_2$-induced oxidative damage. In the result of antioxidant enzyme activity evaluation in cells, enzyme treatments did not show the significant difference of SOD activity (p>0.05). However, pectinase treatment group exhibited increased CAT and GPx activities (p>0.05). Also, pectinase and protease treatment group inhibited MDA formation (>50%) in the lipid peroxidation protection experiment.

• The Korean Journal of Food And Nutrition
• /
• v.31 no.5
• /
• pp.598-603
• /
• 2018

As basic research for optimal barley cultivars selection and technical development for quality maintenance, a total of 21 commercial malt products (for making 'Sikhye', a traditional Korean sweet drink) were collected from the Korean market. And then we analyzed the component of the barley malt products as well as conducted comparative analysis on enzyme activity and quality characteristics of the commercial barley malt products. Of the 21 barley malt products, 12 were made from 100 % barley. The result of analyzing general components of barley malts turned out different level of components; moisture 4.91~11.99%, lipid 1.71~2.48%, protein 7.80~11.97%, carbohydrate 73.64~82.24%, total starch 5.50~8.22%, reducing sugar 3.64~14.44%. As a result of measuring enzyme activity of barley malts, there was a wide range of activity difference by the product; diastatic power $36.80{\sim}94.30^{\circ}$, ${\alpha}$-amylase activity 18.17~186.50 unit/g, ${\beta}$-amylase activity 6.53~25.05 unit/g. The results of this study would be used as basic data for optimal cultivars selection to produce barley malts and technical development for quality maintenance.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.45 no.12
• /
• pp.1732-1739
• /
• 2016

The general components and cyclitol compounds of ice plant (Mesembryanthemum crystallinum) were analyzed to examine the possibility of using extracts as functional food materials, the antioxidant effects and antidiabetic activities of the extracts by solvent fraction were tested. Among the mineral contents, contents of K and Na were the largest ($1,213.33{\pm}2.52$ and $545.53{\pm}12.01mg/100g$, respectively), followed by S, Ca, P, and Mg in order of precedence. Among cyclitol compounds, content of D-pinitol was the largest ($4.04{\pm}0.08mg/g$) while contents of chiro-inositol and myo-inositol were relatively small ($2.82{\pm}0.01$ and $0.25{\pm}0.01mg/g$, respectively). Among total phenol contents by solvent fraction, contents of chloroform and ethyl acetate fractions were large ($35.80{\pm}1.33$ and $23.70{\pm}0.62mg\;GAE/g$, respectively). Among antioxidant activity levels examined by DPPH, ABTS, FRAP, and lipid/MA assays, the chloroform fraction commonly showed the highest level of activity while the ethyl acetate fraction showed relatively high levels of activity. The antioxidant activity levels were proportional to total phenol contents by solvent fraction. As for antidiabetic effects, all solvent fractions showed at least 50% ${\alpha}-glucosidase$ inhibitory activity levels while the ethyl acetate, butanol, and chloroform fractions showed high levels activity of $90.33{\pm}0.40$, $87.98{\pm}0.16$, and $86.38{\pm}0.51%$, respectively. The ${\alpha}-amylase$ inhibitory actively levels were in the range of $25.63{\pm}1.45{\sim}60.34{\pm}2.67%$, which was lower than the ${\alpha}-glucosidase$ inhibitory activity levels, but the inhibitory activity levels by solvent fraction were similar. Given the above study results, ice plant can be utilized as a natural material with antioxidative and antidiabetic functionality.

• Asian-Australasian Journal of Animal Sciences
• /
• v.33 no.1
• /
• pp.91-99
• /
• 2020

Objective: This study investigated the effects of oral administration of rumen-protected L-tryptophan (RPL-T) on duodenal starch digestion and gastrointestinal hormones (GIH) secretions using Hanwoo beef steers as the animal models. Methods: Four steers (423±24 kg) fitted with ruminal and duodenal cannulas were employed in a crossover design replicated twice. Treatments were control (basal diet) and RPL-T (basal diet+191.1 mg/kg body weight [BW]) group. Blood and duodenal samples were collected to measure serum GIH levels and pancreatic α-amylase activity at day 0, 1, 3, and 5 (-30, 30, 90, 150, and 210 min) of the study. Samples from each segment of the gastrointestinal tract were collected via ruminal and duodenal cannulas and were used to determine soluble protein and the starch digestion rate at days 6 (-30, 180, 360, and 540 min) and 8 (-30, 90, 270, and 450 min) of the experiment. Results: No significant difference in ruminal pH, NH₃-N, and total volatile fatty acid including the levels of acetate, propionate, butyrate, isobutyrate, valerate, isovalerate, and the acetate-to-propionate ratio was observed between groups (p>0.05). Crude protein uptake was higher and feces starch content was lower in RPL-T group than the control group (p<0.05). The D-glucose contents of feces in RPL-T group decreased at day 5 compared to those in the control group (p<0.05), however, no change was found at day 0, 1, or 3 compared to the control group (p>0.05). Serum cholecystokinin (CCK), melatonin, duodenal pancreatic α-amylase activity, and starch digestion were significantly higher in RPL-T group than the control group (p<0.05). Conclusion: Taken together, oral administration of RPL-T at the rate of 191.1 mg/kg BW consistently increased CCK concentration, pancreatic α-amylase activity in duodenal fluids, and starch digestion rate in the small intestine and thus found to be beneficial.