• Journal of Microbiology and Biotechnology
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• 제3권4호
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• pp.298-302
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• 1993

Pullulan was produced from starch hydrolysate with Aureobasidium pullulans SH8646. We could measure the correct amount of pullulan produced without the interference of starch from the culture supernatant by using a bacterial $\alpha$-amylase treatment and ethanol: acetone (1:1) precipitation. When 5% acid-hydrolyzed starch was used as a carbon source, the dry cell weights obtained were similar irrespective of DE values of starch hydrolysates. The dry cell weights of those on the starch hydrolysate media prepared with 0.1 N HC1 treatment, were slightly higher (9.5~10.5 g/l) than those on the starch hydrolysate media prepared with 1.0 N HCl (8.5~9.5 g/l). And among the starch hydrolysates showing DE values lower than 50, maximum pullulan production of 15 g/l was obtained at DE 30~40 starch hydrolysate but those showing DE values higher than 50, the pullulan production was increased with the increase of the DE value of starch hydrolysates. From the media containing 5%, 10%, and 15% starch hydrolysate (DE 25, 45, and 75), about 20~34% pullulan yield was obtained and the maximum pullulan yield of 34% (17g/l) was obtained from 5% DE 75 starch hydrolysate. The pullulan yields from starch hydrolysate media were much lower than those from glucose, maltose, maltotriose, and sucrose media.

• 한국식품위생안전성학회지
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• 제12권1호
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• pp.63-70
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• 1997

The extracts from Agastache rugosa O. Kuntze, their chloroform and hexane fractions, and estragole identified from hexane fraction were tested to investigate the effects on the growth and metabolic activities of several true fungi. The fungi used were: Aspergillus oryzae KFCC 890, Aspergillus niger KCCM 11240, Saccharomyces cerevisiae IAM 4597, Saccharomyces ellipsoideus PNU 2215. The growth of S. Cerevisiae by treatment of water extract(1%), hexane fraction (0.05%), and estragole (0.05%) were inhibited 93%, 50%, and 33% respectively, and S. ellipsoideus was also inhibited markedly with delaying the alg phase maximum 12 hrs. The growth of A. oryzae was inhibited by treatment of extracts and fractions. The echanol production by S. cerevisiae was increased more than two times in the highest value around 42 hrs incubation by water extract, but chloroform fraction inhibited its production. The glucoamylase actibities by A. niger were strongly inhibited by hexane and chloroform fractions (0.05%). The invertase activity by S. cerevisiae using estragole (0.05%) reached to 57.5% of control group. S. cerevisiae treated with the estragole was damaged the cell wall and cell membrane, leaked the protoplasm, and observed broken pieces of cell.

• Journal of Applied Biological Chemistry
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• 제50권4호
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• pp.234-238
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• 2007

The effects of ultra-fine pulverization on the physicochemical properties of rice starch (RS) were investigated using a high impact planetary mill. After pulverization, RVA characteristics, peak viscosity, break down, and set back values of RS decreased from 274.75 to 9.42 RVU, 214.46 to 6.17 RVU, and 87.80 to 17.00 RVU, respectively. The pasting properties also changed significantly. X-Ray diffractogram revealed RS had four A-type peaks, which disappeared after pulverization. The peak temperature and gelatinization enthalpy of RS using differential scanning calorimetry (DSC) were 13.99 J/g at $75.14^{\circ}C$, whereas the pulverized RS (PRS) had two peaks, 0.13 J/g at $63.88^{\circ}C$ and 1.23 J/g at $101.24^{\circ}C$. DSC measurement showed the retrogradation degree of PRS was lower than that of RS after storage at 4 and $25^{\circ}C$. The enzymatic (${\alpha}$-amylase) digestibilities of RS and PRS were 72.7 and 77.3%, respectively.

• 한국식생활문화학회지
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• 제12권4호
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• pp.375-382
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• 1997

The establishment of optimal producing condition for rice-based infant foods using modified rice powder was attempted. The modification of rice powder was prepared by microwave heating as well as partial enzymatic hydrolysis. Not only thermal treatment but also enzymatic hydrolysis on rice powder increased D.E. value from 1.25 to 3.81. The water binding capacity, swelling power, solubility, digestibility by ${\alpha}-amylase$, light transparency, and paste clarity of the modified rice powder compared to unmodified rice powder were increased from 107% to 249%, from 7.80 to 42.52, from 0.04% to 0.89ft, from 9.19% to 23.01, from 33% to 42%, and from 2.2% to 3.9%, respectively. On the other hand, gelatinization temperature, apparent viscosity, and degree of retrogradation of modified rice powder showed negative correlation with D.E. value. The 「results suggested that the thermal and enzymatic treatment on rice powder improved the physicochemical properties of rice based infant food by enhancing carbohydrate absorptionability and lowering the viscosity and opacity.

• Journal of Microbiology and Biotechnology
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• 제4권4호
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• pp.305-315
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• 1994

Nineteen strains of bacteriocin-producing lactic acid bacteria were isolated from 432 Kimchi samples, and identified by the comprehensive biochemical and morphological tests verifying their cellular fatty acid composition. Using partially purified bacteriocins from these isolates, their inhibitory activities against other lactic acid bacteria and some pathogens, and sensitivity to enzyme and heat treatments were tested. The isolates were identified as Lactobacillus plantarum (2 strains), L curvatus (2 starins), L brevis (2 strains), Enterococcus faecium (6 strains), Leuconostoc mesenteroides subsp. mesenteroides (1 strain) and Lactobacillus sp. (6 strains). The bacteriocins produced by E. faecium strains provided the broadest spectrum of inhibition, affecting against other Gram-positive bacteria including lactic acid bacteria and health-threatening bacteria such as Clostridium perfringens and Listeria monocytogenes. The bacteriocins of Lactobacillus sp., L plantarum and L brevis strains were capable of inhibiting many strains of the lactic acid bacteria, whereas those of L curvatus and L mesenteroides subsp. mesenteroides strains were only inhibitory to a few strains. Generally, the inhibitory activities of both E. faecium and Lactobacillus sp. strains were greater than those of other producer strains. The bacteriocins from the isolates were sensitive to several proteolytic enzymes, and those of L curvatus and L mesenteroides subsp. mesenteroides were also sensitive to lipase and $\alpha$-amylase as well as to proteolytic enzymes. The bacteriocins from the strains of Lactobacillus sp. and a strain of L. brevis were resistant to autoclaving.

• Food Science and Biotechnology
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• 제14권1호
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• pp.49-57
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• 2005

Enterococcus faecium MJ-14, having strong antilisterial activity, was isolated from Korean fermented food, Meju. MJ-14 showed the same phenotypic characteristics, but different sugar utilization, as reference strain, E. faecium KCCM12118. It could utilize D-xylose, amygdaline, and gluconate, whereas E. faecium KCCM12118 could not. Optimal condition for bacteriocin production by E. faecium MJ-14 was at $37^{\circ}C$ and pH 7.0. Bacteriocin activity appeared in mid exponential phase and increased rapidly up to stationary phase. Activity was significantly promoted in MRS broth containing 3.0% glucose, 1.5% lactose, 2.0% peptone, or 1.5% tryptone. Bacteriocins effectively inhibited Enterococcus faecalis and Listeria spp. of Gram-positive bacteria, and Helicobacter pylori of Gram-negative bacteria, but did not inhibit yeasts and molds. They were stable against heat (for 30 min at $100^{\circ}C$), pH (3.0-9.0), long-term storage (for 60 days at 4 or $-20^{\circ}C$), and enzymatic digestion by catalase, proteinase K, papain, lysozyme, trypsin, chymotrypsin, and lipase, etc. Bacteriocin activity was completely inhibited by protease and pepsin, and 50% by ${\alpha}$-amylase. Studies on PCR detection of enterocin structural genes revealed bacteriocins are identical to enterocins A and B.

• 한국식품저장유통학회지
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• 제14권6호
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• pp.650-654
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• 2007

식혜 고유의 시원한 맛과 인삼의 독특한 맛을 가미한 인삼식혜를 제조하기 위해 본 연구에서는 엿기름 20 g, 고두밥 400 g을 기준으로 하여 여기에 각 인삼분말을 고두밥양의 $3{\sim}12%$, teramyl효소 0.2 mL을 각각 첨가한 후 인삼식혜 제조에 있어 당화공정의 특성을 분석하였다. 인삼식혜의 당화공정은 일반 식혜의 당화공정과 같이 당화 온도 및 당화 시간이 증가할수록 당화력이 증가 하는 경향을 보였다. 하지만 본 실험에서 제조한 인삼식혜의 유리당 분석을 한 결과 식혜고유의 주성분인 말토오스 함량이 일반 식혜보다 훨씬 높은 4.3%이상의 농도를 나타내고 있어 시판식혜에 비해 우수한 품질의 특성을 보였다.

• Preventive Nutrition and Food Science
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• 제15권4호
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• pp.360-363
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• 2010

To enhance the expression and secretion of pediocin PA-1 from heterologous bacterial hosts, the promoter and deduced signal sequence (PS) of an $\alpha$-amylase gene from a Bifidobacterium adolescentis strain was fused with pediocin PA-1 structural and immunity genes (AB) and the resulting functions were evaluated in Escherichia coli. Two recombinant PCR products were created-one with just the deduced signal sequence and one with the sequence plus the Ser and Thr sequences that are the next two amino acids of the signal sequence. These two products, the PSAB (---AQA::KYY---) and PSABST (---AQA$\underline{ST}$::KYY---), respectively, were inserted into a TA cloning vector (yT&A) and named pPSAB, which was previously reported, and pPSABST. The two recombinant plasmid DNAs were transferred into E. coli JM109 and the transformants displayed antimicrobial activity, where the activity of E. coli JM109 (pPSAB) was stronger than that of E. coli JM109 (pPSABST), indicating that the ST amino acid residues were not necessary for secretion and might have even decreased the antimicrobial activity of recombinant pediocin PA-1.

• 펄프종이기술
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• 제45권6호
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• pp.78-87
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• 2013

Even though the notice No. 2010-11 of the Ministry of Food and Drug Safety Administration that has been applied to analyze the content of the water soluble residue eluted from multi-layer paperboard was abolished in 2011, its application for the analysis on evaporation residue is still valid. There are very high possibilities that the noticed existing method gives the misleading result on the evaporation residue due to the water soluble starch eluted from the multi-layer paperboard. The quantitative analysis on water-soluble residue with starch content correction has been carried in the study using UV/Vis spectroscopy and HPLC. The UV/Vis spectroscopy absorbance analysis showed the large amount of the oxidized starch obtained from the aqueous residue eluted out of the multi-layer paperboard after the iodine, ${\alpha}$-amylase reaction, and starch hydrolysis. The residual content decreased by the correction through the enzyme hydrolysis.

• 한국식품조리과학회지
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• 제19권2호
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• pp.136-143
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• 2003

This study was carried out to investigate the quality of bread made with different types of brown rice flours. 20% of the wheat flour from the bread recipe was substituted with the different types of brown rice flours, such as, raw brown rice flour (RBRF), soaked brown rice flour (SOBRF), and sprouted brown rice flour (SPBRF). The loaf volume of the bread: decreased by 3.2%∼7.4% with the addition of the brown rice flours. The "L" value of these breads decreased, while the "a" and "b" values increased. In terms of the texture, the SPBRF bread was the hardest on the 1st day of storage, but it was the least hard on the 5th day of storage. The RBRF bread was the least springy. The SPBRF bread was the most cohesive. The adhesiveness was not significantly different among the breads. In terms of the degree of retrogradation using the ${\alpha}$-amylase method, the SOBRF and SPBRF breads showed a little lesser degree of retrogradation than the control and the RBRF bread. In the sensory evaluation, the control bread obtained high score for crumb color and grain, while the brown rice flours breads obtained high scores for mouthfeel and taste. Overall acceptability, defined by a higher score, was higher for the SOBRF and SPBRF breads than the control bread, which was not significant. Thus, this study showed that processing rice flour was more effective than raw rice flour in substituting wheat flour.