• Title/Summary/Keyword: bacterial

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Effect of Pediocin Treatment on Soybean curd Quality during Storage (Pediocin 용액침지가 두부의 저장성에 미치는 영향)

  • Park, Su-Jung;Park, Kee-Jai;Jeong, Seong-Weon;Kim, Seok-Joong;Youn, Kwang-Sup
    • Food Science and Preservation
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    • v.14 no.2
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    • pp.131-135
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    • 2007
  • We investigated the effects of pediocin on physicochemical and microbial changes in soybean cut 9 days of storage at $10^{\circ}C$, in order to improve shelf-life. As the storage time of curd increased the pH of solutions treated by pediocin immersion did not vary greatly, whereas the pH of control curd decreased after 5 days of storage. Titratable acidity increased in non-treated curd after 5 days of storage, and also in cud immersed in pediocin solutions of 300 and 500 ppm, after 6 and 7 days of storage, respectively. A pediocin solution of 1,000 ppm the development of titratable acidity. Also, turbidity did not increase during storage of curd treated with a pediocin solution of 1,000 ppm. The bacterial count of the immersion solution was $10^{2.5}$ CFU/mL at the commencement of storage, remained stable for 5 days of storage, and then increased rapidly. Coliforms were detected in untreated curd after 2.5days of storage. In curd treated with 300, 500 or 1,000ppm of pediocin, the elapsed times to coliform detection were 3.5 days, 5 days and 7 days, respectively, It is thus possible to prevent the deterioration of soybean curd with pediocin treatment.

Effects of Chaenomelis Fructus Water Extract on the Quality Characteristics of Mul-kimchi during Fermentation (모과 추출액이 물김치의 품질 특성에 미치는 영향)

  • Park, La-Young;Jeong, Tae-Seong;Lee, Shin-Ho
    • Food Science and Preservation
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    • v.15 no.5
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    • pp.669-674
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    • 2008
  • Mul-kimchi is more watery than traditional kimchi and is prepared using large amounts of salted water, Chinese cabbage, radishes, and carrots. The quality characteristics of Mul-kimchi prepared with Chaenomelis Fructus water extract (1, 3, or 5%, w/v) (CF Mul-kimchi) or water (control) were investigated during fermentation for 21 days at $10^{\circ}C$. The initial pH values were 6.53 (control), 4.14 (1% CF Mul-kimchi), 3.61 (3% CF Mul-kimchi), and 3.54 (5% CF Mul-kimchi). The pH did not change significantly in CF Mul-kimchi but gradually decreased in the control during fermentation. Changes in titratable acidity were reflected in pH movements. Viable lactic acid bacteria in CF Mul-kimchi were at lower levels than in the control. Viable bacterial levels in Mul-kimchi decreased with increasing concentration of CF water extract. Textural features, such as hardness, cohesiveness, chewiness, and springiness, were higher in CF Mul-kimchi than in control. Anti-oxidative activity, measured by DPPH radical scavenging and nitrite scavenging, of CF Mul-kimchi, were higher than in control, and the activities rose with increasing levels of CF water extract. The sensory qualities of 1% CF Mul-kimchi showed the highest values in taste and overall acceptability among the Mul-kimchi preparations tested.

Effect of Aqueous Chlorine Dioxide and Citric Acid on Reduction of Salmonella typhimurium on Sprouting Radish Seeds (이산화염소수 및 구연산처리에 따른 무(Raphanus sativus L.) 새싹과 종자의 미생물 제어 효과)

  • Park, Kee-Jai;Lim, Jeong-Ho;Kim, Bum-Keum;Kim, Jong-Chan;Jeong, Jin-Woong;Jeong, Seong-Weon
    • Food Science and Preservation
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    • v.15 no.5
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    • pp.754-759
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    • 2008
  • The effect of citric acid-aqueous chlorine dioxide ($ClO_2$) treatment of radish seeds artificially contaminated with Salmonella typhimurium was studied. Radish seeds were inoculated by immersion, in more than 106 log CFU/g seed, of a suspension of S. typhimurium, dried, and stored sealed at $4^{\circ}C$ Radish seeds soaked in 200 ppm aqueous ClO2 solution for 10 min showed a bacterial reduction of 1.08 log CFU/g seed, and the lowering of microbial burden noted in seeds soaked in 2% (w/v) citric acid solution for 10 min was 2.89 log CFU/g seed. Next, radish seeds were exposed to 0.5% (v/v) glycerol solution for 10 min either before or after treatment with 200 ppm aqueous ClO2 or 2% (w/v) citric acid for 10 min. Glycerol exposure after citric acid treatment reduced bacteria by 3.46 log CFU/g seed, and glycerol treatment after aqueous $ClO_2$ treatment reduced the microbial burden by 2.14 log CFU/g seed. Both glycerol treatments yielded better elimination of S. typhimurium than did a single treatment with either citric acid or aqueous $ClO_2$. Radish seeds inoculated with S. typhimurium were treated throughout the entire growth period. Although radish seed treatment was effective, treatment by citric acid and aqueous $ClO_2$ after sprouting was not effective to eliminate S. typhimurium.

Isolation of Egg-Contaminating Bacteria and Evaluation of Bacterial Radiation Sensitivity (계란 오염 세균의 분리 및 분리 균주의 감마선 감수성 평가)

  • Kim, Dong-Ho;Yun, Hye-Jeong;Song, Hyun-Pa;Lim, Byung-Lak;Jo, Cheo-Run
    • Food Science and Preservation
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    • v.15 no.5
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    • pp.774-781
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    • 2008
  • was performed and Staphylococcus sciuri, Bacillus cereus, Escherichia coli, Proteus mirabilis, and Enterococcus faecalis were identified. No Salmonella strain, a typical contaminant of eggs, was found. The radiation sensitivities of isolated bacteria and Salmonella typhimurium, in an inoculated model system, were expressed in $D_{10}$ values. The ranges of $D_{10}$ values shown by S. typhimurium, S. sciuri, B. cereus, E. coli, P. mirabilis, and E. faecalis were 0.365-0.399 kGy, 0.418-0.471 kGy, 1.075-1.119 kGy, 0.280-0.304 kGy, 1.132-1.330 kGy, and 0.993-1.290 kGy, respectively. The growth of all six test bacteria in eggs (inoculated at $10^6-10^7\;CFU/g$) during 3 days of post-irradiation storage at ambient conditions ($25^{\circ}C$) was recorded. S. typhimurium was eliminated by irradiation at 3 kGy, and E. coli and S. sciuri were eliminated by irradiation at 5 kGy. The viable cell counts of B. cereus, P. mirabilis, and E. faecalis in eggs showed 4-6 log reductions after irradiation with 5 kGy.

Quality Characteristics and Shelf Life of Noodles Prepared with Heracleum moellendorffii(Hogweed) Powder (어수리분말 첨가 국수의 품질특성 및 저장성)

  • Nam, Yoo-Hwa;Hong, Joo-Heon;Youn, Kwang-Sup;No, Hong-Kyoon;Lee, Shin-Ho
    • Food Science and Preservation
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    • v.17 no.5
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    • pp.602-607
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    • 2010
  • The quality characteristics and shelf life of wet noodles containing a freeze-dried powder of Heracleum moellendorffii(HM) were studied to investigate the use of HM as a food ingredient. The weight, volume, and water absorption of wet noodle sprepared with HM(HML) decreased as the concentration of HM increased. The turbidity of HML sauce and the loss in the solid content of noodles after cooking were lower than those of control noodles. Whiteness(L) and redness(a) values of wet noodles decreased but yellowness(b) increased after addition of HM. The sensory qualities of HML, including appearance, taste, color, flavor, texture, and overall acceptability, were better than those of control noodles. Addition of HM to 0.6%(w/w) afforded the best sensory qualities with respect to taste, texture, and overall acceptability. The total polyphenol content of HML increased as HM concentration increased. Noodle DPPH free-radical-scavenging activities were 22%(control), 28.41%(0.3%HM addition), 40.22%(0.6%HM addition) and 49.42%(0.9%HM addition). Viable bacterial cell counts did not differ significantly between control noodles and those prepared using 0.6%(w/w)HM during storage for 6day sat $10^{\circ}C$. However, viable cell numbers in noodles prepared using 0.9%(w/w) HM were significantly lower than those of control samples and of noodles prepared using either 0.3%(w/w) or 0.6%(w/w) HM, during storage for 12 days at $10^{\circ}C$. Changes in pH values showed trends similar to those of viable cell numbers during storage.

Antimicrobial Activity Screening of Sixty-four Evergreen Woody Species According to Extraction Conditions against Trichophyton mentagrophytes (상록성 목본 64종의 추출조건에 따른 무좀원인균의 항균활성 스크리닝)

  • Jang, Bo Kook;Chi, Lai Won;Cho, Ju Sung;Lee, Cheol Hee
    • Korean Journal of Plant Resources
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    • v.31 no.4
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    • pp.330-341
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    • 2018
  • This study was performed to investigate and measure the antimicrobial activity of evergreen woody species extracts on Trichophyton mentagrophytes. To do this, leaves and stems were collected from Wando and Jeju islands, and were used for the extraction with different solvents (i.e., distilled water, 80% ethanol, and 100% methanol), and at different ultrasonic extracting times (i.e., 15, 30, and 45 minutes). The experiment was conducted by using the agar diffusion method. The clear zone was measured after incubating the paper disc containing the plant extract in a bacterial culture medium. The controls were synthetic antimicrobials, methylparaben and phenoxyethanol, at concentrations of 0.4, 1, 2, and 4 mg/disc. Altogether, extracts of 56 out of 64 species used in this study had inhibitory activity, which confirmed their antimicrobial activity against Athlete's foot. Among them, the crude ethanolic extract of Elaeocarpus sylvestris in 45 min showed a zone of inhibition < 20.2 mm, while the clear zone of Actinodaphne lancifolia ethanolic extraction for 30 min was 23.5 mm. Also, Quercus acuta, Dendropanax morbiferus and Daphne odora showed clear zones of 28.0 mm (45 minutes ethanolic extraction), 20.5 mm (45 minutes crude methanolic extraction) and 19.7 mm (45 minutes methanolic extraction), respectively. Thus, these results confirm that the extracts of evergreen woody species have therapeutic potential against Athlete's foot, and suggest that in order to extract adequate amounts of antimicrobial substance from the plant sources, ideal extraction condition has to be considered.

Quality Characteristics of Canned Boiled Oyster and Canned Boiled Oyster in Bamboo Salt in Various Sterilization Conditions (살균조건에 따른 굴 보일드통조림 및 죽염 굴 보일드통조림의 식품 품질 특성)

  • Kong, Cheong-Sik;Je, Hae-Soo;Jung, Jae-Hun;Kwon, Soon-Jae;Lee, Jae-Dong;Yoon, Moon-Joo;Choi, Jong-Duck;Kim, Jeong-Gyun
    • Journal of Fisheries and Marine Sciences Education
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    • v.26 no.6
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    • pp.1231-1244
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    • 2014
  • Oysters, especially are excellent source of several mineral including iron, zinc and selenium, which are often low in the mordern diet. They are also an excellent source of glycogen, vitamin B12 and considered the healthiest when eaten raw on the half shell in good tasted season from November to March. This study was investigated for the purpose of obtaining basic data which can be applied to processing of two kinds of canned boiled oyster (canned boiled oyster, canned boiled oyster in bamboo salt). Shucked oyster meat was cooked in steam (15min) after washing with water, filled 90g into can (301-3), added with salt solution and then precooked for 10 min. at $100^{\circ}C$. Canned boiled oyster was added 1.5% salt solution 60mL. Canned boiled oyster in bamboo salt was added 0.5% salt solution 30mL and 0.7% bamboo salt solution 30mL. The cans were seamed using a vacuum seamer, and then sterilized for various Fo values (Fo 8~12 min.) in a steam system retort at $116^{\circ}C$, $118^{\circ}C$. Viable bacterial count, proximate composition, pH, salinity, yield, VBN, amino-N, TBA, mineral, color value, free amino acid, hardness and sensory evaluation of two kinds of canned boiled oyster produced at various sterilization condition (Fo 8~12 min.) were measured after divide to meat and juice. The results showed that canned boiled oyster in bamboo salt sterilized at Fo 8 min. was the most desirable because this condition is the most economical and tasty.

Phosphate Solubilization and Plant Growth Promotion by Crop Associated Bacteria (인산용해미생물에 의한 불용성 인의 용해와 식물생장에 미치는 영향)

  • Na, Jung-Heang;Choi, Jin-Ho;Jin, Rong-De;Ko, Hyun-Sun;Park, Ro-Dong;Kim, Kil-Yong
    • Korean Journal of Soil Science and Fertilizer
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    • v.42 no.1
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    • pp.29-36
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    • 2009
  • Fourteen bacterial strains were isolated from crop rhizosphere and identified as phosphate solubilizing bacteria (PSB) by 16S rRNA analysis. Only 3 strains exhibited a strong ability to solubilize insoluble phosphate in agar medium containing a hydroxyapatite. The rates of P solubilization by isolates were ranged from 200 and $2300\;mg\;L^{-1}$, which are inversely correlated with pH in culture medium. Furthermore, HPLC analyses reveal the production of organic acid from the culture filtrates of PSB. Among these, strain Acinetobacter sp. released only gluconic acid, Pseudomonas orientalis produced gluconic acid which was subsequently converted into 2-ketogluconic acid, and Enterobacter asburiae released acetic acid and succinic acid. On the other hand, P. orientalis and E. asburiae released $372\;mg\;L^{-1}$ and $191\;mg\;L^{-1}$ of IAA into broth culture, respectively, while Acinetobacter sp. did not produce IAA. Furthermore, in vivo study showed that plant growth promoting effect by bacteria generally seemed to be increased IAA production and phosphate solubilization.

Phosphate Solubilizing Activity of Pseudomonas sp. CL-1 and Kluyvera sp. CL-2 (Pseudomonas sp. CL-1 및 Kluyvera sp. CL-2 균주의 인산가용화 특성)

  • Kwon, Jang-Sik;Suh, Jang-Sun;Weon, Hang-Yeon;Kim, Wan-Gyu;Noh, Hyung-Jun
    • Korean Journal of Soil Science and Fertilizer
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    • v.40 no.6
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    • pp.442-446
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    • 2007
  • From the rhizoplane and rhizosphere of pepper, tomato, lettuce, pasture, and grass, unsoluble inorganic phosphate solubilizing bacterial strains were isolated using plate base assay on Pikovskaya's medium. Two strains, CL-1 and CL-2, which produced largest halo on plates (indicative of phosphate solubilization)were selected for further studies. Based on these biochemical and 16S rRNA analysis strains CL-1, CL-2 were found to be as species of Pseudomonas sp. and Kluyvera sp., respectively. In broth assay Pseudomonas sp. CL-1 and Kluyvera sp. CL-2 solubilized insoluble phosphate by 193.4 mg and $493.6P\;mg\;L^{-1}$, respectively after $3^{rd}$ day inoculation. These effecient phosphate solubilizing bacteria have a potential to be developed as microbial based fertilizer in future.

Formulation of a rational dosage regimen of ceftiofur hydrochloride oily suspension by pharmacokinetic-pharmacodynamic (PK-PD) model for treatment of swine Streptococcus suis infection

  • Luo, Wanhe;Wang, Dehai;Qin, Hua;Chen, Dongmei;Pan, Yuanhu;Qu, Wei;Huang, Lingli;Xie, Shuyu
    • Journal of Veterinary Science
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    • v.22 no.6
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    • pp.41.1-41.14
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    • 2021
  • Background: Our previously prepared ceftiofur (CEF) hydrochloride oily suspension shows potential wide applications for controlling swine Streptococcus suis infections, while the irrational dose has not been formulated. Objectives: The rational dose regimens of CEF oily suspension against S. suis were systematically studied using a pharmacokinetic-pharmacodynamic model method. Methods: The healthy and infected pigs were intramuscularly administered CEF hydrochloride oily suspension at a single dose of 5 mg/kg, and then the plasma and pulmonary epithelial lining fluid (PELF) were collected at different times. The minimum inhibitory concentration (MIC), minimal bactericidal concentration, mutant prevention concentration (MPC), post-antibiotic effect (PAE), and time-killing curves were determined. Subsequently, the area under the curve by the MIC (AUC0-24h/MIC) values of desfuroylceftiofur (DFC) in the PELF was obtained by integrating in vivo pharmacokinetic data of the infected pigs and ex vivo pharmacodynamic data using the sigmoid Emax (Hill) equation. The dose was calculated based on the AUC0-24h/MIC values for bacteriostatic action, bactericidal action, and bacterial elimination. Results: The peak concentration, the area under the concentration-time curve, and the time to peak for PELF's DFC were 24.76 ± 0.92 ㎍/mL, 811.99 ± 54.70 ㎍·h/mL, and 8.00 h in healthy pigs, and 33.04 ± 0.99 ㎍/mL, 735.85 ± 26.20 ㎍·h/mL, and 8.00 h in infected pigs, respectively. The MIC of PELF's DFC against S. suis strain was 0.25 ㎍/mL. There was strong concentration-dependent activity as determined by MPC, PAE, and the time-killing curves. The AUC0-24h/MIC values of PELF's DFC for bacteriostatic activity, bactericidal activity, and virtual eradication of bacteria were 6.54 h, 9.69 h, and 11.49 h, respectively. Thus, a dosage regimen of 1.94 mg/kg every 72 h could be sufficient to reach bactericidal activity. Conclusions: A rational dosage regimen was recommended, and it could assist in increasing the treatment effectiveness of CEF hydrochloride oily suspension against S. Suis infections.