• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1635-1641
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• 1999

Bacillus subtilis PCA20-3 was isolated from meju and was found to produce a protease. The strain produced the maximum amount of enzyme in the medium containing soytone (0.2%), soluble starch (2%), $(NH_4)_2SO_4\;(0.1%),\;CaCl_2(0.1%),\;yeast\;extract\;(0.01%),\;K_2HPO_4\;(0.1%),\;and\;KH_2PO_4\;(0.1%)$. Protease was first concentrated by ammonium sulfate (80% saturation, w/v) precipitation of culture supernatant. Then the enzyme was purified by column chromatography using CM Sephadex C-50. The collected proteins were rechromatographed using Sephadex G-100 gel filtration column. The fraction with protease active from Sephadex G-100 gel chromatography was found to be pure when examined by SDS-polyacrylamide gel electrophoresis and YMC-pak reverse phase chromatography. Specific activity, yield and purity were 76 U/mg. 2.7%, and 7.6 fold, respectively. The molecular weight of the enzyme was estimated to be 31.5 kDa by SDS-PAGE. The number of amino acids calculated from molecular weight was evaluated about 321 residues. N-terminal sequence of the enzyme was $Val^1-Pro^2-Tyr^3-Gly^4-Val^5-Ser^6-Gln^7-Gly^8-Lys^9-Ala^{10}$.

• Korean Journal of Food Science and Technology
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• v.35 no.2
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• pp.235-241
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• 2003

Yogurt base was prepared from whole and skin milk added with $0.5{\sim}2.0%\;(w/v)$ of cultured ginseng ethanol extract and fermented with lactic acid bacteria (Streptococcos thermophilus : Lactobacillus bulgaricus=1:1) at $37^{\circ}C$ for $24{\sim}30\;h$. Quality characteristics of the yogurt were evaluated in terms of acid production, number of viable cells, viscosity, and sensory property during lactic acid fermentation. Total contents of amino acids and some organic acids were analyzed. Addition of cultured ginseng extract stimulated the growth of lactic acid bacteria, and enhanced acid production and viscosity of yogurt. Total contents of amino acids of 0.5% cultured ginseng-added yogurt were higher than control group before fermentation, whereas glutamic acid, cysteine, valine, and phenyalaine contents increased after 30 h incubation. Contents of lactic, citric, and formic acids of 0.5% cultured ginseng-added yogurt increased during fermentation for 24 h. whereas decreased thereafter. Sensory scores of yogurts added with 0.5 and 1 % cultured ginseng extract were significantly higher than other groups in taste and overall acceptability. When cultured ginseng yogurt was kept at $5^{\circ}C$ for 15 days, its quality-keeping property was relatively good.

• Journal of the Korean Society of Food Culture
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• v.9 no.4
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• pp.411-417
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• 1994

The extraction condition and quality attributes components in Oolong tea were investigated. Extraction yield was high in $80{\sim}85^{\circ}C$ above 50% ethanol solution. Sucrose content most high among the free sugar ranged $37.2{\sim}55.0\;mg/100\;g$, while arabinose was the least. Organic acids in ethanolic extracts were furmaric, citric and malic acid. Free amino acids were 15 kinds and contents of proline, tyrosine and glutamic acid were comparatively high. Tannin content extracted from water and 25% ethanol solution were 38.6 and $38.5\;{\mu}g/100\;g$, it decreased as ethanol concentration increase. Caffeine content did not changed as extraction conditions. Ascorbic acid content was $6.5\;{\mu}g/g$ when extracted from 25% ethanol solution, it decreased as ethanol concentration increase. Bitter and astringent taste affected to overall preference of Oolong tea. Tea manufactured from 25% ethanol solution extracts recorded most high organoleptic score than any other extraction condition.

• Research in Plant Disease
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• v.21 no.2
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• pp.99-102
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• 2015

Cucumber mosaic virus (CMV) is one of the most destructive viruses in chilli pepper. An isolate of CMV was obtained from the chilli pepper cv. Chungyang showing top necrosis symptom in 2013 and designated as CMV-GTN. CMV-GTN was compared with the well-characterized isolate, CMV-Ca-P1, by investigating their amino acid sequences of the coat protein (CP) and biological reactions in several host plants. The CP of CMV-Ca-P1 composed of 217 amino acids but that of CMV-GTN composed of 218 amino acids by including additional valine in the $57^{th}$ amino acid position. Amino acid sequence similarity of the CP gene among CMV-GTN and other CMV isolates recorded in the GeneBank database ranged from 96% to 99%. CMV-GTN was selected as a representative isolate to screen the resistance pepper cultivars to CMV because it was highly pathogenic to tomatoes and peppers upon biological assays. The virulence of CMV-GTN was tested on 135 pepper cultivars which has been bred in Korea and compared with that of CMV-Ca-P1. Only the cv. Premium was resistant and three cvs. Hot star, Kaiser, and Good choice were moderately resistant to CMV-GTN, whereas two cvs. Baerotta and Kaiser were resistant to CMV-Ca-P1.

• Journal of Plant Biotechnology
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• v.41 no.4
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• pp.229-235
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• 2014

Gastrodia elata Blume, an achlorophyllous orchid plant, has been used in traditional medicine and harvests in spring and fall. Here we investigated the quantitative changes of amino acids in G. elata by harvest times and seed tubers. In the results, we found that there was not big difference in contents of total amino acids but the distribution of amino acids differed depending on harvest times. 19% of total amino acids were asparagin and valine, an essential amino acid, occupied 10% within total amino acids in the tubers harvested in October. Among amino acids in the tubers harvested in April, serine occupied 23% and arginine, an essential amino acid, occupied 10% within total amino acids in tuber. Interestingly, the use of sexually propagated seed tubers produced high concentration of total amino acids compared to vegetatively propagated seed tubers. As for sexually propagated seed tubers, essential amino acids contents similar to the tubes harvested in October and nonessential amino acids contents similar to the tubers harvested in April. In this study, we found that amino acids contents in G. elata tubers altered depending on various cultivation practices. Therefore if these results can be applied to food industry, the value of G. elata as a natural food resource will be enhanced to a great extent.

• Journal of the Korean Society of Food Culture
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• v.10 no.4
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• pp.321-326
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• 1995

This study was conducted to derive consumption of persimmon by the expansion of utilization of the persimmon flesh and peel. The valuable components were investigated in persimmon flesh and peel. Crude protein and fat contents in persimmon peel were higher than flesh but soluble sugar was more higher in flesh (with 71.3%) than peel (with 54.2%). Major free sugar in persimmon peel were glucose and fructose, the composition was similar to flesh. Major total amino acids in persimmon peel were glutamic acid, proline, methionine and aspartic acid. Proline, arginine, valine and alanine were relatively high in free amino acid. Oleic acid, linoleic acid and palmitic acid were the major fatty acid in persimmon peel, and the content of unsaturated fatty acid was more higher than flesh. Sugar cookies were processed using persimmon flesh and peel, when these powder were mixed with $5{\sim}10%$ to raw materials, the preference score was increased. Steamed rice cakes with persimmon were processed using persimmon flesh and peel, when sliced-dried persimmon was mixed to $10{\sim}20%$, the preference was increased, but persimmon peel was not. The quality of gruel which processed using persimmon flesh powder improved when mixed with flesh powder of 3%, rice powder, glutinous rice powder and skimmed milk, but persimmon peel was not suitable for gruel processing.

• Food Science and Preservation
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• v.19 no.6
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• pp.893-900
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• 2012

To establish a new manufacturing process of low-salted fermented anchovy sauce, commercial fermented anchovy sauce with 23% NaCl was desalted using a spirit. The proximate composition, total nitrogen, amino nitrogen, Escherichia coli, and total and free amino acid contents were analyzed to evaluate the quality characteristics of commercial salted fermented anchovy sauce (CFAS) and low-salt fermented anchovy sauce by desalting processing (LFAS). The salinity of saltwater and fermented anchovy sauce decreased with an increase in the spirit added to 23% NaCl saltwater and 23% NaCl commercial fermented anchovy sauce. The total nitrogen and amino nitrogen contents were higher in LFAS than in CFAS. The major amino acids that were commonly found in CFAS and LFAS were glutamic acid, alanine, lysine and leucine. Basic data were provided for commodification research on low-salt fermented anchovy sauce, which is very important for the diet of humans.

• Journal of Animal Science and Technology
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• v.63 no.3
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• pp.531-544
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• 2021

Heat stress (HS) damages health and decreases performance variables in pigs, and if severe enough, causes mortality. However, metabolic changes under HS and recovery following HS are poorly understood. Therefore, this study was aimed to expose the essential mechanisms by which growing pigs respond to HS and the temporal pattern of plasma concentrations (PC) of amino acids (AAs) and metabolites. Crossbred male growing pigs were penned separately and allowed to adapt to thermal-neutral (TN) conditions (20℃ and 80% relative humidity; TN[-1D]). On the first day, all pigs were exposed to HS for 24 h (36℃ and 60% relative humidity), then to TN conditions for 5 days (TN[2D] to TN[5D]). All pigs had ad libitum access to water and 3 kg feed twice daily. Rectal temperature (RT) and feed intake (FI) were determined daily. HS pigs had higher RT (40.72℃) and lower (50%) FI than TN(-1D) pigs (p < 0.01). The PC of indispensable (threonine, valine, and methionine) and dispensable (cysteine and tyrosine) AAs were higher (p < 0.05) in HS than TN(-1D) pigs and remained increased during recovery time. Nonprotein α-aminobutyric acid and β-alanine concentrations were higher (p < 0.05) in HS than TN(-1D) pigs. The metabolite concentration of creatinine was higher (p < 0.01) under HS treatment than other treatments, but that of alanine and leucine remained increased (p < 0.05) through 5 d of recovery. In summary, some major differences were found in plasma AA profiles and metabolites between HS- and TN-condition pigs. This indicates that the HS pigs were forced to alter their metabolism, and these results provide information about mechanisms of acute HS responses relative to the recovery time.

• Korean Journal of Clinical Laboratory Science
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• v.53 no.3
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• pp.217-224
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• 2021

Fluoroquinolone (FQ) resistant gram-negative pathogens have emerged worldwide, and the recent increase in FQ resistant Escherichia coli is of great concern in Korea. This study investigated FQ resistance determinants and the epidemiological relationship of 56 ciprofloxacin-resistant E. coli isolated from a tertiary hospital in Daejeon, South Korea from June to December 2018. Molecular epidemiology was investigated by multilocus sequence typing (MLST). Polymerase chain reaction (PCR) and sequence analysis were performed to identify chromosomal mutations in the quinolone resistance determining regions (QRDR) of gyrA, gyrB, parC, and parE and to describe the occurrence of the following plasmid-mediated quinolone resistance (PMQR) genes: aac(6)-Ib-cr, qepA, qnrA, qnrB, qnrC, qnrD, and qnrS. MLST analysis showed 12 sequence types (STs) and the most prevalent ST was ST131 (31/56, 55.4%), followed by ST1193 (13/56, 23.2%), and ST405 (3/56, 5.4%). In 56 ciprofloxacin-resistant E. coli isolates, Ser83→Leu and Asp87→Asn in gyrA and Ser80→Ile and Glu84→Val in parC (51.8%, 29/56) were the most frequent amino acid substitutions and aac(6)-Ib-cr (33.9%, 19/56) was the most common PMQR gene. These results of FQ resistance determinants were more frequently observed in ST131 compared with other clones. Continuous monitoring of the epidemiological characteristics of ciprofloxacin-resistant E. coli isolates and further investigation of FQ resistance determinants are necessary.

• Journal of Plant Biotechnology
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• v.48 no.2
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• pp.77-85
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• 2021

Hydroponic cultivation, in which crops are grown without soil and are unaffected by the weather, has many advantages over conventional soil cultivation. The crop's growth can be further accelerated by using nutrient solution in place of water. This study investigated the growth and physicochemical properties of hydroponic barley sprouts under various nutrient solution and artificial light treatments. The shoot, root, and total plant length increased over time, with the fastest growth occurring in the nutrient solution and light-emitting diode (LED) treatments. Fresh and dry plant weights were higher in the fluorescent lamp treatment than in the LED treatment. Barley sprout powder color differed slightly by treatment, with the Hunters L value ranging from 50.79 to 53.77; Hunters a value from -6.70 to -4.42; and Hunters b value from 13.35 to 14.76. The Hunters L and Hunters b values were highest in the LED treatment, whereas the Hunters a value was relatively highest in the fluorescent lamp treatment. The total phenol content was higher in the control than in the nutrient solution treatment; however, the total flavonoid content showed the opposite pattern to that of total phenol content, being highest in plants that were grown in nutrient solution. The Trolox equivalent antioxidant capacity (TEAC) was higher in the control group than in the nutrient solution group. The ferric ion reducing antioxidant power (FRAP) was higher in the fluorescent treatment group than in the LED treatment group. The total amino acid composition ranged from 106.82 to 122.63 mg/g dry powder, with the essential amino acid composition ranging from 47.01 to 56.19 mg/g, and non-essential amino acid composition from 67.86 to 77.66 mg/g. The most frequently detected compositional amino acid was aspartic acid, followed by glutamic acid, alanine, leucine, and valine.