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Lee TS Lee SW Seok WS Yoo MY Yoon JW Park BK Moon KD Oh DH 《Journal of food protection》2004,67(6):1123-1127
A total of 673 ready-to-eat vegetable samples were collected in Korea from 2001 to 2002 and analyzed for the presence of Yersinia spp. We analyzed biotypes, serotypes, and susceptibility to 12 antibiotics and tested for virulence genes of pathogenic Yersinia enterocolitica isolates by PCR assay. Among the samples, 27 (4.0%) were found to be contaminated with Yersinia spp. Among the 27 strains of Yersinia spp. isolates, 18 strains (66.7%) of Y. enterocolitica, 5 strains (18.5%) of Y. frederiksenii, 3 strains (11.1%) of Y. intermedia, and 1 strain (3.7%) of Y. kristensenii were identified. According to the serotypes of Y. enterocolitica isolates, O:3 (11.1%) and O:5 (11.1%) were the most predominant, followed by O:8 (5.6%) and others (72.2%). For biotypes of Y. enterocolitica isolates, 1A (77.8%) was the most predominant, followed by 3B (11.1%), 3 (5.6%), and 5A (5.6%). Also, an antibiotic susceptibility test showed that Y. enterocolitica isolates were very susceptible to the antibiotics tested but highly resistant to ampicillin (94%), cephalothin (100%), and carbenicillin (83%). PCR assays with specific primers derived from yst and ail genes of Y. enterocolitica were applied to confirm the presence of pathogenic Y. enterocolitica. Among the 18 strains of Y. enterocolitica isolates, only 3 strains (O:3/1A, UT/3B, and UT/1A isolated from Chinese cabbage, onion, and spinach, respectively) were shown to have a virulence gene. 相似文献
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Jaedeuk Park Jae Hyun Cho Heon Jung Kwang-Deog Jung Il Moon 《International Journal of Hydrogen Energy》2014
This article details comprehensive energy and exergy analyses of the sulfuric acid decomposition process of the sulfur–iodine (SI) thermochemical cycle for hydrogen production. Energy and exergy efficiencies of the proposed process were evaluated over a variety of reaction temperatures and pressures. At an atmospheric temperature of 25 °C, the calculated values of exergy destruction of the H2SO4 decomposer ranged between 157 kJ/mol and 360 kJ/mol over reaction temperatures of 800–1000 °C and pressures between 1 and 50 atm. It was shown that the exergy efficiency of the H2SO4 decomposer improved with an increase in reaction temperature, while reaction pressure had a negative effect on exergy efficiency. 相似文献
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Occurrence and characterization of enterotoxigenic Staphylococcus aureus isolated from minimally processed vegetables and sprouts in Korea 总被引:1,自引:0,他引:1
Staphylococcus aureus has long been recognized as an important pathogen in food-borne disease in the world. Minimally processed vegetables and
sprouts are often contaminated with enterotoxigenic strains of this bacterium. This paper reports the results of a 3-year
survey (2006–2008) on the occurrence of S. aureus in minimally processed vegetables and sprouts. Of 345 examined samples, 40 samples (11.6%) were contaminated with S. aureus. A total of 25 enterotoxigenic S. aureus strains were biotyped and their resistance to antibiotics was examined. Most isolated strains produced Staphylococcal enterotoxin
A (SEA) (n=23) followed by Staphylococcal enterotoxin I (SEI) and Staphylococcal enterotoxin G (SEG) and mainly belonged to the human
biotype (88%). At least 96.1% of the analyzed strains showed antibiotic resistance properties, while 56% of the analyzed strains
exhibited multiple antibiotic resistance to the antibiotics tested. Two of the analyzed strains were resistant to methicillin.
Moreover, a strain which had multi-resistance to 6 antibiotics was found. The results indicate that enterotoxigenic, antibioticresistant
strains of S. aureus are widely proliferated in minimally processed vegetables and sprouts. 相似文献
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Hakbeum Lee Won-Il Kim Kwang-Deog Jung Hyoung Lim Koh 《Korean Journal of Chemical Engineering》2017,34(5):1337-1345
We investigated the effects of different Cu weight ratio on θ or γ-Al2O3 which were impregnated with platinum in terms of catalytic activity for propane dehydrogenation and physicochemical properties. 1.5 wt% Pt, 0-10 wt% Cu catalyst supported on θ-Al2O3 or γ-Al2O3 was prepared by incipient wetness co-impregnation. Enhanced Pt dispersion by increasing Cu contents in γ-Al2O3 supported catalyst was confirmed via XRD and XPS. Pt and CuO was separated in Pt-Cu/θ-Al2O3, but Pt-Cu alloy was identified after reduction treatment. Also, adding Cu in Pt/Al2O3 makes catalyst’s acidity lower and this property led to increased propylene yield in propane dehydrogenation. However, Pt3Cu was not good for yield of PDH, which was confirmed in Pt-10Cu/θ-Al2O3 through XRD. 相似文献
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The change in browning characteristics of the slices processed from ‘Tsugaru’ apples stored at 0 °C for 5 months under controlled atmosphere (CA, 1 kPa O2 + 1 kPa CO2, 3 kPa O2 + 3 kPa CO2) or air has been investigated for 5 days at 20 °C. Respiration and ethylene production of the slices from apples stored in CA were retarded. Electrolyte leakage and browning index were lower in the slices from apples stored under CA than air. Vitamin C and phenolic contents in the slices from apples stored under air were maintained at higher level compared to the slices from apples stored under CA. Polyphenol oxidase activity in the slices was not affected by pre-slicing storage atmospheres. Therefore, the atmospheres of pre-slicing storage affected browning development in fresh-cut products of ‘Tsugaru’ apples and browning was found to be correlated with the levels of electrolyte leakage and phenolic compounds. 相似文献
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Sang-Woo Park Oh-Shim Joo Kwang-Deog Jung Hyo Kim Sung-Hwan Han 《Korean Journal of Chemical Engineering》2000,17(6):719-722
The stability and the activity of Fe2O3/Cr2O3 and ZnO/Cr2O3 catalysts were examined for a reverse-watergas-shift reaction (RWReaction). The initial activities of those catalysts were
quite high so that the conversion reached close to equilibrium. The activity of Fe2O3/Cr2O3 catalyst decreased from 33.5 to 29.8% during the RWReaction for 75 h at 873 K with GHSV (ml/gcat · h) of 100,000. Moreover,
the coke formation on the Fe2O3/Cr2O3 catalyst caused clogging in the RWReactor of the CAMERE process. On the other hand, the ZnO/Cr2O3 catalyst showed no coke formation and no deactivation for the RWReaction at 873 K with GHSV (ml/gcat · h) of 150,000. The
ZnO/Cr2O3 was a good catalyst for the RWReaction of the CAMERE process. 相似文献
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Hun-Sik Chung Do-Hee Kim Kwang-Sup Youn Joo-Baek Lee Kwang-Deog Moon 《Food science and biotechnology》2013,22(1):23-29
Response surface methodology (RSM) was used to determine the optimal roasting temperature and roasting time of coffee beans used for preparing brews with high antioxidant activity and sensory quality. Green coffee beans (Coffea arabica L. cv. Colombia Organic Tamata) were roasted at temperatures ranging from 140 to 220°C for 2–10 min and were then brewed with dripping hot water. The effects of the roasting conditions on the browning index, antioxidant activity, color, aroma, taste, and overall acceptability of the coffee brewed from the bean were investigated using a second-order central composite design. The quality indicators except the taste were significantly affected by roasting temperature and time, tending to increase and then decrease with increasing roasting temperature and time. Superimposed contour plots indicated that the optimal roasting temperature was 182°C and optimal roasting time was 7 min. 相似文献