• Journal of Food Hygiene and Safety
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• v.31 no.6
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• pp.406-413
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• 2016

This study was performed to evaluate and establish a sample preparation method for the detection of food-borne pathogens in animal origin foods. Ham, yogurt, and Korean beef inoculated with Escherichia coli O157:H7, Staphylococcus aureus, and Salmonella Typhimurium, were tested for the effects of diluent composition, processing time, and proportion of diluent to sample. The diluents used were peptone water (PW), Saline solution (SS), Butterfield's phosphate buffered dilution water (BPD), and Buffered peptone water (BPW). The processing time periods considered for the samples were 30, 60, 90, 120, and 300 sec, and the proportions of diluent to samples tested were 1:2, 1:4, 1:9, and 1:19. Yogurt and beef showed the highest number of bacteria when treated with BPW (p < 0.05). However, ham showed no significant difference between the treatments with four different diluents. Optimum proportions of diluent to ham, yogurt, and beef were 1:9, 1:2, and 1:4, respectively. The processing time of 120 sec was chosen as optimum, because it showed the best recovery rate in all sample types. In this manner, detection of food-borne bacteria with the selected optimal conditions was indicated by a recovery rate of more than 85%. These data suggest that an appropriate diluent composition and diluent volume should be used depending on the type of sample, which would thereby increase the accuracy of detecting food-borne bacteria in animal origin foods.

• Journal of Dairy Science and Biotechnology
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• v.31 no.2
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• pp.153-159
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• 2013

Lactic acid bacteria are microorganisms that are closely associated with human and/or animal environments, and are categorized as generally recognized as safe (GRAS) organisms due to their ubiquitous appearance in foods and their contribution to the healthy microflora of mucosal surfaces. This study was performed to isolate and identify lactic acid bacteria with antagonistic effects against food-borne pathogens. A total of 3,000 acid-producing bacteria were isolated from infant feces, cattle feces, goat feces, dog feces, pig feces, vaginal tracts, vegetables, fruits, Kimchi, Jeotgal, fermented sausages, raw milk, cheese, yogurt, Cheonggukjang, Meju, and Makgeolli cultured on MRS agar with 0.05% bromocresol purple. For the isolation of bacteriocin-producing bacteria, the diameter of the clear zone was measured on MRS agar plates. Twenty-six isolates exhibited strong antibacterial activity against indicator strains such as Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella enterica serovar Enteritidis. Lactic acid bacteria were identified as Enterococcus faecalis, Enterococcus faecium, Enterococcus hirae, Lactobacillus acidophilus, Lactobacillus amylovorus, Lactobacillus curvatus, Lactobacillus plantarum, and Pediococcus acidilactici by 16S rDNA gene sequence analysis. The results of this study suggest that the isolates could be used as potential probiotic starters for functional food applications.

• Journal of Pharmacopuncture
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• v.19 no.3
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• pp.225-230
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• 2016

Objectives: Mellitine, a major component of bee venom (BV, Apis mellifera), is more active against gram positive than gram negative bacteria. Moreover, BV has been reported to have multiple effects, including antibacterial, antivirus, and anti-inflammation effects, in various types of cells. In addition, wasp venom has been reported to have antibacterial properties. The aim of this study was to evaluate the antibacterial activity of BV against selected gram positive and gram negative bacterial strains of medical importance. Methods: This investigation was set up to evaluate the antibacterial activity of BV against six grams positive and gram negative bacteria, including Staphylococcus aureus (S. aureus), Salmonella typhimurium, Escherichia coli (E. coli) O157:H7, Pseudomonas aeruginosa, Burkholderia mallei and Burkholderia pseudomallei. Three concentrations of crude BV and standard antibiotic (gentamicin) disks as positive controls were tested by using the disc diffusion method. Results: BV was found to have a significant antibacterial effect against E. coli, S. aureus, and Salmonella typhyimurium in all three concentrations tested. However, BV had no noticeable effect on other tested bacteria for any of the three doses tested. Conclusion: The results of the current study indicate that BV inhibits the growth and survival of bacterial strains and that BV can be used as a complementary antimicrobial agent against pathogenic bacteria. BV lacked the effective proteins necessary for it to exhibit antibacterial activity for some specific strains while being very effective against other specific strains. Thus, one may conclude, that Apis mellifera venom may have a specific mechanism that allows it to have an antibacterial effect on certain susceptible bacteria, but that mechanism is not well understood.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.5
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• pp.751-755
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• 2006

Dadih is Indonesian traditional fermented buffalo milk believed by the natives to have beneficial effects on human health. This may be due to the probiotic properties possessed by the lactic acid bacteria (LAB) involved in its fermentation process. It was discovered that ten strains of dadih lactic isolates possessed some probiotic properties in vitro. In this study, the adhesion properties of dadih LAB, in comparison with documented probiotic strains, were investigated in vitro by using mucin extracted from human faeces and Caco-2 cells as the models for human intestinal mucosal surface and intestinal cells respectively. The adhesion results showed the distinction of Lactobacillus reuteri IS-27560 in adhering to both mucus layer and Caco-2 cells. The competition assay for adhesion to the mucus layer between dadih LAB and selected pathogens indicated the competence of Lactococcus lactis IS-16183 and Lactobacillus rhamnosus IS-7257 in significantly inhibiting the adhesion of Escherichia coli O157:H7. Accordingly, these two strains may be potential candidates for use as probiotic strains. Overall, the adhesion properties of all dadih LAB strains were relatively comparable to that of Lactobacillus casei Shirota and Lactobacillus rhamnosus GG, the documented probiotic strains.

• Food Science of Animal Resources
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• v.40 no.2
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• pp.221-230
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• 2020

The aim of this study was to evaluate the antioxidant and antibacterial activity of Hovenia (Hovenia dulcis) monofloral honey produced in Korea. To produce Hovenia monofloral honey, Hovenia trees were surrounded by a net house, and honeybees were breed there over a 20-day period. Hovenia monofloral honey contained more than 95% of Hovenia pollen and showed physicochemical properties in agreement with the international honey standard (Codex). The total phenolic and flavonoid contents of Hovenia monofloral honey ranged from a 24.82-27.00 mg gallic acid equivalent/100 g honey and a 0.41-0.46 mg quercetin equivalent/100 g honey, respectively. In addition, to evaluate the functional properties of Hovenia monofloral honey, the antioxidant activity of Hovenia monofloral honey was estimated by using the 1,1-diphenyl-2-picrylhydrazyl radical and the 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging assay. Furthermore, Hovenia monofloral honey showed an antibacterial activity against foodborne gram positive (Listeria monocytogenes and Staphylococcus aureus) and gram negative bacteria (Salmonella Typhimurium and Escherichia coli O157:H7).

• Journal of Microbiology
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• v.38 no.1
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• pp.8-10
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• 2000

In order to rapidly identify and differentiate Salmonella typhimurium from the intestinal gram-negative bacteria, randomly amplified polymorphic DNA (RAPD) fingerprinting of Salmonella typhimurium was carried out using random primers designated OPA-13 (5'-CAGCACCCAC-3'), OPB-10 (5'-CGTCTGGGAC-3'), OPB-18 (5'-CCACAGCAGT-3'), and OPJ-10 (5'-AAGCCCGAGG-3'), and its patterns compared with 6 representive intestinal, gram-negative bacterial strains, Vibrio parahaemolyticus, V. vulnificus, Enterobacter cloacae, Escherichia coli O157:H7, Pseudomonas aeruginosa, and Proteus sp., which are often found in foods. S. typhimurium had unique and distinct fingerprinting patterns. RAPD fingerprinting is thus concluded to be a rapid and sensitive method for the identification of S. typhimurium compared to conventional culturing procedures or immunoassays.

• Preventive Nutrition and Food Science
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• v.17 no.2
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• pp.172-176
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• 2012

Doenjang is a traditional Korean fermented soybean product that provides a major source of protein. In this study, a total of 18 different home-made doenjang samples were examined for the presence of foodborne pathogens and the total aflatoxin levels. Using an enzyme-linked immunosorbent assay to assess microbial quality and potential public health risk, we showed that total coliform levels in the doenjang samples ranged from 0 to $4.43{\pm}2.32{\times}10^6\;CFU/g$, and the maximum limit of Bacillus cereus was $4.67{\pm}2.0{\times}10^5\;CFU/g$. However, other foodborne pathogens, such as Staphylococcus aureus, Escherichia coli O157:H7 and Salmonella spp., were not detected among the tested samples. One of the samples (S3) showed a maximum limit of $42.2{\pm}9.1\;{\mu}g/kg$ for aflatoxin levels, which was above the safety limit allowed by the Codex Alimentarius Commission (CAC) regulatory agency. Further research is necessary to determine whether and how doenjang safety can be improved via elimination/reduction of microbial contamination during fermentation and storage or using microbial starter cultures for its fermentation.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.276-276
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• 2013

Here we report an integrated microdevice consisting of an efficient passive mixer, a magnetic separation chamber, and a capillary electrophoretic microchannel in which DNA barcode assay, target pathogen separation, and barcode DNA capillary electrophoretic analysis were performed sequentially within 30 min for multiplex pathogen detection at the single-cell level. The intestine-shaped serpentine 3D micromixer provides a high mixing rate to generate magnetic particle-pathogenic bacteria-DNA barcode labelled AuNP complexes quantitatively. After magnetic separation and purification of those complexes, the barcode DNA strands were released and analyzed by the microfluidic capillary electrophoresis within 5 min. The size of the barcode DNA strand was controlled depending on the target bacteria (Staphylococcus aureus, Escherichia coli O157:H7, and Salmonella typhimurium), and the different elution time of the barcode DNA peak in the electropherogram allows us to recognize the target pathogen with ease in the monoplex as well as in the multiplex analysis. In addition, the quantity of the DNA barcode strand (~104) per AuNP is enough to be observed in the laser-induced confocal fluorescence detector, thereby making single-cell analysis possible. This novel integrated microdevice enables us to perform rapid, sensitive, and multiplex pathogen detection with sample-in-answer-out capability to be applied for biosafety testing, environmental screening, and clinical trials.

• Food Science and Biotechnology
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• v.14 no.4
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• pp.474-478
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• 2005

Because it possesses anti-inflammatory, antifungal, antiviral, and tissue regenerative properties, propolis has been used for thousands of years in folk medicine for multiple purposes. Although the antimicrobial activity of propolis has already been demonstrated, very few studies have been conducted on bacteria of clinical relevance in dentistry. The aim of this study is to evaluate the antimicrobial, anti-inflammatory, and anti-oxidative activities of 0.1% and 1.0% propolis, both of water-extracted (proAQ) and ethanol-extracted (proAL) propolis, for industrial applications. In studies of antimicrobial activity, the growth of Staphylococcus aureus ATCC 35556, Salmonella enteritidis ATCC 12021, Escherichia coli O157:H7, and Candida parapsilosis KCCM 35428, all general food or clinical pathogens, were tested. The culture medium used was trypticase soy broth including 0.6% yeast extract; after 6 hr of incubation, the turbidities were measured at 620 nm with a spectrophotometer. The results indicate that the antimicrobial effects of both 1.0% proAQ and 1.0% proAL were greater against the growth of S. aureus ATCC 35556 and C. parapsilosis KCCM 35428 rather than those of S. enteritidis ATCC 12021 and E. coli O157:H7. Additionally, it appears that the anti-inflammatory effects of proAL are greater than those of proAQ. The anti-inflammatory effects were evaluated by measurement of the inhibition of hyaluronidase activity in vitro. At a 1% concentration, the anti-inflammatory effects of proAL were greater than those of proAQ. Finally, the anti-oxidative effects of 1% and 10% solutions of each extract sample were measured according to the TBA method at $40^{\circ}C$ for 1, 2, 3, and 5 days and were compared with 1.0% BHT. The results indicate that the anti-oxidative effects at 0.1% for both proAQ and proAL were not significantly different than the anti-oxidative effects at 1.0% BHT (p<0.05). Thus, it appeared that the alcohol-extracted propolis had greater antimicrobial, anti-inflammatory, and anti-oxidative effects than the water-extracted propolis. This is based on the presumption that major biofunctional components were fat-soluble, rather than water-soluble.

• Journal of Applied Biological Chemistry
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• v.58 no.2
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• pp.145-151
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• 2015

Corn fiber protein (CFP) was extracted from corn wet-milling by-product, corn fiber. CFP films containing various plasticizers and cross-linking agents were prepared and their mechanical properties were determined. Among the plasticizers and cross-linking agents used in this study, the CFP film containing 2 g fructose and 0.03% cinnamaldehyde had the most appropriate physical property. In addition, the CFP films containing green tea extract (GTE) were prepared by incorporating different amounts (0, 0.5, 1.0, 1.5%) of GTE into the film-forming solution. Tensile strength, film solubility, and opacity of the CFP films increased with the addition of GTE, whereas elongation and water vapor permeability of the CFP/GTE films decreased compared to those of the control. The antioxidant activity of the CFP/GTE film was determined in terms of 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity. As a result, antioxidant activity of the films increased with increasing GTE concentration. Furthermore, antimicrobial activity against Escherichia coli O157:H7, Listeria monocytogenes, and Staphylococcus aureus increased with increasing GTE concentration. These results indicate that the incorporation of GTE could enhance antioxidant and antimicrobial activities of the CFP films.