• Food Science and Preservation
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• v.23 no.6
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• pp.797-803
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• 2016

In this study, we investigated the effect of fermentation conditions on the amylolytic and proteolytic activities of Aspergillus luchuensis strain 74-5 and Aspergillus oryzae strain 75-2, which are used in the preparation of the starter culture, for Takju (Korean traditional rice wine). The starter culture was optimized using different conditions, such as inoculum size, inoculation temperature, and incubation time. The enzyme activities under each condition were measured. In the A. luchuensis strain 74-5 starter culture, the ${\alpha}-amylase$ and glucoamylase activities increased, however the activity of acidic protease decreased as the diluent to starter culture ratio increased. In the A. oryzae 75-2 starter culture, all enzyme activities were maintained at a higher level even at 5% inoculation ratio. Higher enzyme activities were observed in the middle range of inoculation temperature (35, $40^{\circ}C$), than in the lower range (20, $30^{\circ}C$). Enzyme activity in the starter culture varied with incubation time, however it was the highest at 144 and 120 hr, respectively, for A. luchuensis strain 74-5 and A. oryzae strain 75-2. The spore count of the starter culture was approximately $2{\times}10^7$ during fermentation, out of which contamination by aerobic bacteria was about $3{\times}10^3$. The results suggested that the starter culture of each strain could be used as an inoculum for fermentation. However, we needs to conduct further research for the selection of suitable diluting agents as well as drying methods to reduce the contamination by aerobic bacteria, while retaining the enzyme activity.

• Korean Journal of Microbiology
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• v.46 no.2
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• pp.192-199
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• 2010

The alone and combined effects of bacteriocin produced from Enterococcus faecalis MJ-213 and potassium sorbate against the food-borne pathogenic bacteria were studied. Bacteriocin minimal inhibitory concentration (MIC) values for Staphylococcus aureus ATCC 6538 and Salmonella enteritidis ATCC 13076 were 50 and 100 ${\mu}g$/ml, respectively. Bacteriocin (100 ${\mu}g$/ml) alone was active against S. aureus and S. enteritidis, but it was lower in antimicrobial effectiveness than the combination of bacteriocin (100 ${\mu}g$/ml) with potassium sorbate (100 ${\mu}g$/ml), which reduced initial counts (6 log cycle) of S. aureus and S. enteritidis by 1 and 3 log cycle, respectively. The bactericidal activity of bacteriocin of E. faecalis MJ-213 heated at $100^{\circ}C$ for 30 min or $121^{\circ}C$ for 15 min was markedly decreased as compared with the control. Moreover, the activity of bacteriocin was completely abolished by pepsin or protease II, but not affected by ${\alpha}$-amylase or lipase. The activity of bacteriocin adjusted to pH 6.0-8.0 showed almost the same inhibition ratio compared with the bacteriocin unadjusted pH, and though the inhibition ratio against pathogenic bacteria was reduced than the control, the bacteriocin was stable at pH 4.0 or 10.0, relatively. Furthermore, the combined treatment of bacteriocin and potassium sorbate than the alone treatment of bacteriocin significantly decreased (p<0.05) the viable cell counts of S. aureus or S. enteritidis inoculated on grind beef during storage at $4^{\circ}C$.

• Food Science and Preservation
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• v.24 no.1
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• pp.125-133
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• 2017

This study evaluated the changes of physiochemical properties, phytochemical contents, and biological activities during the vinegar fermentation of Elaeagnus multiflora fruit. The contents of pH and reducing sugar decreased from 3.55 and 6.88 mg/mL 3.34 and 2.13 mg/mL, respectively. However the acidity increased from 0.48% to 5.48% during the vinegar fermentation. The alcohol contents increased up to a maximum value of 6.6% at 20 days, and it then decreased at the end fermentation days (2.0%). The viable numbers of acetic acid bacteria and yeasts increased from 4.32 log CFU/mL and 3.23 log CFU/mL at 10 days to 5.4 log CFU/mL and 5.5 log CFU/mL during the spontaneous fermentation, respectively. The major organic acids were acetic acid (38.84 mg/mL), lactic acid (4.92 mg/mL), and malic acid (1.51 mg/mL). The soluble phenolic and flavonoid contents increased from 0.79 mg/mL and 0.12 mg/mL of initial fermentation day to 1.22 mg/mL and 0.14 mg/mL during the spontaneous fermentation. Content of epicatechin gallate decreased from $168.1{\mu}g/mL$ at 10 days to $115.97{\mu}g/mL$. However the content of gallic acid increased from $18.52{\mu}g/mL$ to $95.07{\mu}g/mL$ during fermentation. After 60 days of the fermentation, the antioxidant and digestive enzyme inhibitory activities were 71.35% (DPPH), 79.27% (ABTS), 68.72% (${\cdot}OH$), 85.42% (${\alpha}$-glucosidase), 52.12% (${\alpha}$-amylase), and 53.66% (pancreatic lipase), respectively.

• Korean Journal of Poultry Science
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• v.46 no.2
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• pp.117-125
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• 2019

The aim of the study was to investigate the effects of dietary supplementation of zinc (Zn) sources (zinc oxide and Zn-methionine) on performance, organ weights, blood biochemical profiles, and digestive enzymes of the pancreas and small intestine in Korean native chicks (KNC). A total of 144 KNC (n=6) were fed a basal diet (CON, 100 ppm of Zn), a basal diet supplemented with 50 ppm of Zn with ZnO (ZNO), or a basal diet supplemented with 50 ppm of Zn with Zn-methionine (ZMT) for 28 days. There was no significant difference in body weight, gain, feed intake, and feed conversion ratio among the three groups. The relative weights of the liver, spleen, and intestinal mucosa were unaffected by the dietary source of Zn, whereas pancreas weight in the ZNO group decreased (P<0.05) compared with that in the CON and ZMT groups. Blood biochemical components including aspartate aminotransferase, and alanine aminotransferase were unaffected by dietary Zn supplementation. Pancreatic trypsin activity in the ZNO and ZMT groups was significantly (P<0.05) enhanced compared with that in the CON group. However, the activities of ${\alpha}$-amylase and carboxypeptidase A were not altered by dietary Zn supplementation. The activities of maltase and sucrase were unchanged, whereas the activity of leucine aminopeptidase tended (P=0.08) to be increased by dietary Zn supplementation. In conclusion, the supplementation with 50 ppm of ZnO or Zn-methionine resulted in an activation of protein digestive enzymes in the pancreas and small intestine without affecting animal performance in KNC.

• Korean Journal of Food Science and Technology
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• v.44 no.5
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• pp.607-612
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• 2012

Dandelions were fermented for 120 days at $15-20^{\circ}C$ in batches containing thirty and fifty percent raw sugar (FD30 and FD50). The total phenolic concentration of FD30 and FD50 were about $78.9{\pm}2.17$ and $59.35{\pm}2.56$ mg/g, respectively, both being higher than the 2$54.{\pm}1.49$ mg/g determined for DWE (dandelion water extract). The DPPH radical scavenging activity of FD30 and FD50 showed $IC_{50}$ values of $118.7{\pm}2.03$ and $123.40{\pm}2.15{\mu}g/mL$, respectively, and FD30 displayed the highest antioxidant activity. 2 mg/mL of FD30 and FD50 showed $8.8{\pm}1.72$ and $11.8{\pm}2.87{\mu}M$ production of NO, respectively, compared with $4.9{\pm}1.20{\mu}M$ of the dandelion extract. The protease, ${\alpha}$-amylase, and lipase activity of FD50 was the highest. The fibrinolytic activity of FD30 and FD50 were $0.56{\pm}0.28$ and $1.39{\pm}0.20$ unit/mg protein, respectively, which was substantially higher than the 0.28 unit/mg protein of DWE. In conclusion, the dandelions fermented by sugar showed improved antioxidant, anti-inflammatory and enzymatic activities.

• Korean Journal of Microbiology
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• v.48 no.2
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• pp.147-155
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• 2012

To improve of the quality of Korea traditional wheat-rice wine (makgeolli) production, we used a rice fermentation starter (rice nuruk) made by inoculation of Rhizopus oryzae CCS01 which was isolated and selected from commercial nuruk. Amylase activity of a rice nuruk was 1.8-2.4 times higher than those of commercial nuruks. The best acceptability of wheat-rice wine in a sensory test was observed at 4 : 6 ratio of wheat-rice mash at experimental condition. During the fermentation period, pH of wheat-rice makgeolli made with a rice nuruk was higher compared to those made with commercial nuruks such as Sanseong, Jinju, and Songhak. Acidity of makgeolli mash was lower in case of using a rice nuruk and birx and alcohol production were higher compared to those of makgeolli mash using commercial nuruks. Highest alcohol production was observed at makgeolli mash using a rice nuruk and 12% of alcohol was produced at fermentation end. These results suggest that production of a new type of wheat-rice makgeolli using a rice nuruk was possible.

• Journal of Life Science
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• v.25 no.2
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• pp.206-213
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• 2015

Sunsik has been popular as well-being and healthy food to some Asian people, but it still has a limit to other foreigners because of its taste and appearance. This study tried to modify Sunsik into smoothie type for foreigners and investigate its physicochemical characteristics. Germinated black and brown rice was prepared. The germination condition of two cereals was steeping for 24 hr at room temperature, and then germinating for 24 hr at $30^{\circ}C$. After germination, the ${\alpha}$-amylase activity of germinated grains was 13~15 times higher than before germination. The enzyme activity of brown rice was 9.16 CU/g, but germinated brown rice was 152.63 CU/g. In case of black rice, enzyme activity before germination was 7.47 CU/g, and enzyme activity after germination was 97.96 CU/g. The lactic acid bacteria was grown in 50 g germinated brown rice powder with 100 ml malt solution, 30 g tomato juice, and 1.5 g rice bran. After manufacturing beverage using milk and Sunsik and the cell count of lactic acid bacteria was $1.3{\times}10^5CFU/ml$ enough to use starter. According to sensory test, the optimal concentration of Sunsik smoothie was 30 g Sunsik in 200 ml of milk. The viscosity was $5.97{\pm}1.2$ centipoise. The color of Sunsik beverage was evaluated as L value : $63.50{\pm}0.41$, a value: $-0.35{\pm}0.06$, and b value: $8.85{\pm}0.19$.

• Korean Journal of Medicinal Crop Science
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• v.13 no.6
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• pp.293-299
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• 2005

To determine optimal fermentation period of vegetables mixed with black sugar without innoculation of microorganisms, changes in chemical components, quality characteristics of the fermented broth and physiological functionality during the fermentation period were investigated, pH and $^{\circ}BX$ of the fermented broths were decreased gradually during the fermentation period. Except for radish, L and a color values of fermented broths were increased but b values were decreased during fermentation period. Viscosity of fermented broths of vegetables were decreased after 3 months of fermentation. ${\alpha}-Amylase$ activity in fermentation broth of brocolli, eggplant, cabbage, chicory, aralia, radish were increased to 460, 430, 180, 420, 560, 260 after six months fermentation period. In radish and tomato fermentation broth, invertase activity were increased to 200 and 460 units and cellulase activity were increased to 280 and 140 after six months fermentation period. The content of total phenolic compounds and electron donating ability were the highest after 2 to 4 months fermentation period and decreased thereafter. No significant level of tyrosinase inhibitory activity and SOD-like activity were observed. In the sensory evaluation test of aralia fermentation broth of droop, sweet and sour flavor and bitter, astringent taste were decreased during the fermentation period and droop tastes were highest in 3 months. In radish fermentation broth, radish flavor and pungent taste were decreased and sweet taste was increased during fermentation period. Acceptability in overall was the greatest after three months. Based on the results stated above, optimal fermentation period was appropriated 3 or 4 months.

• Journal of Microbiology and Biotechnology
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• v.13 no.3
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• pp.451-456
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• 2003

An expression vector system was developed for the secretory production of recombinant Bacillus stearothermophilus L1 lipase in Saccharomyces cerevisiae. The mature L1 lipase gene was fused to ${\alpha}-amylase$ signal sequence from Aspergillus oryzae for the effective secretion into the culture broth and the expression was controlled under GAL10 (the gene coding UDP-galactose epimerase of S. cerevisiae) promoter. S. cerevisiae harboring the resulting plasmid successfully secreted L1 lipase into the culture broth. To examine an optimum condition for L1 lipase expression in the fed-batch culture, L1 lipase expression was induced at three different growth phases (early, mid, and late-exponential growth phases). Maximum product on of L1 lipase (1,254,000 U/l, corresponding to 0.65/1) was found when the culture was induced at an early growth phase. Secreted recombinant L1 lipase was purified only through CM-Sepharose chromatography, and the purified enzyme showed 1,963 U/mg of specific activity and thermoalkalophilic properties similar to those reported for the enzyme expressed in Escherichia coli.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.2
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• pp.270-276
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• 2008

The purpose of the present study was to investigate the effects of exogenous non-starch polysaccharides (NSP) enzymes on performance, intestinal content viscosity and digestive enzyme activities of growing pigs fed a rough rice-based diet. A total of 60 crossbred barrows with an initial body weight of 35.16 kg (SD = 0.82) were blocked by body weight and randomly assigned to two treatments with three replications. Each group was fed the diet based on rice with or without exogenous NSP enzymes (2 g/kg of diet). During the 70 days of the feeding trial, all pigs were given free access to feed and water. At the end of the feeding trial, six pigs from each treatment were randomly selected and slaughtered to collect intestinal digesta, intestinal mucosa, and pancreas. The addition of NSP enzymes improved average daily gain (p<0.05) and feed:gain (p<0.05), and decreased viscosity of digesta in the jejunum (p<0.001) and ileum (p<0.01) of pigs. The supplementation of NSP enzymes increased activities of protease (p<0.01), trypsin (p<0.01) and ${\alpha}$-amylase (p<0.05) in duodenal contents. However, digestive enzymes in the pancreas, jejunal and ileal mucosa were unaffected by the supplemental NSP enzymes (p>0.10). The results indicate that the addition of NSP enzymes to rough rice-based diets improved performance of pigs, reduced viscosity and increased digestive activity in the small intestine.