Progress 10/01/09 to 09/30/14
Outputs
Target Audience: Target audiences include the produce industry, professionals and scientists in the area of microbiology, food science, biotechnology, and food safety; the food industry; the general public and consumers. The results of projects are shared with the public and the food industry through extension and outreach activities, which benefit local, regional, and state agriculture and the food industry. The results of the projects are presented in national and international meetings, conferences, workshops, and published in scientific refereed journals. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? This project provided opportunities for training graduate students, research assistants, undergraduate and high school students. Students were able to present the research results at the international conferences. Many awards have been received through research competitions. How have the results been disseminated to communities of interest? The results of the study have been published. This study has also been presented at international conferences such as International Association for Food Protection European Symposium and Institute of Food Technology (IFT) Annual Meetings and and to the food industry. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
During the 5 years, we have completed many projects under the two objectives. Specific significant findings are summarized as follows. We developed a label-free DNA based colorimetric method based on AuNPs sandwich hybridization for rapid detection of E. coli O157:H7. AuNPs sandwich hybridization controlled by temperature and high concentration of salt solution can be used as a rapid, simple, and inexpensive detection method for E. coli O157:H7 and the result can be read by eyes without any optical equipment. We developed a novel, simple gaseous chlorine dioxide (ClO2) method that could effectively control microorganisms on potatoes during storage. Results were effective for yeasts and molds, natural microbiota, and P. aeruginosa. Gaseous ClO2 did not affect the overall visual quality of the potato. The residue of ClO2 decreased to < 1mg/l after 14 days consistently for each treatment. We develop a simple gaseous ClO2 method for disinfection of spinach and blueberries using bag approach. Results were effective for decontamination of E. coli O157:H7 on spinach using the slow release and the treatment did not affect visual quality of spinach leaves. For blueberry study using the fast release, a 5.86 log CFU/g reduction was achieved. We investigate the antimicrobial effect of cranberry concentrate (Vaccinium macrocarpon) on Escherichia coli O157:H7 on the gene regulation level. The gene expression levels of the examined genes in E. coli O157:H7 were significantly altered by the cranberry concentrate. Compared to the control samples, genes of slp, hdeA, and cfa were markedly downregulated (P < 0.05), ompC was slightly down regulated, while osmY was slightly affected. We investigated if burgers supplemented with the berry concentrate mixture could be accepted by panelists using a hedonic test. Results showed burgers with 2.5% and 5% had no significant differences from control burgers (0% berry concentrate mixture) in appearance, flavor, and texture, and overall acceptability. Burgers supplemented with the berry mixture may be a potential safe and healthy product preferred by consumers. We developed a real-time enrichment and detection system for viable Escherichia coli O157:H7 and Listeria monocytogenes by a piezoelectric biosensor quartz crystal microbalance (QCM). The real-time biosensor detection established in our study could be used to enrich and detect viable cells simultaneously, giving great potential for pathogenic analysis when the system is applied in food samples. We developed a biosensing method based on aggregation of oligonucletide-functionalized gold nanoparticles (AuNPs) due to sandwich hybridization of probes and the complementary target sequence for the detection of E. coli O157:H7 by naked eyes. It was found that the AuNPs sandwich hybridization method was very specific for E. coli O157:H7 only. The AuNPs sandwich hybridization assay optimized can be used as a rapid, inexpensive and highly specific detection method for E. coli O157:H7 without needing an optical instrument. We investigated what bioactive compounds in cranberries are majorly responsible for the antimicrobial activity of cranberries against foodborne pathogens, particularly Escherichia coli O15:H7. The results indicated that each fraction showed significant antimicrobial effects (P < 0.05) compared to the control (0%) at 24h. We developed chitosan films containing cranberry concentrate and tested for antibacterial activity on poultry drumsticks over a period of 5 days. Due to the antibacterial nature of these films, they present themselves as an effective means of naturally treating poultry with cranberry in a manner that does not cause aesthetic detriment to the product. We discovered the antimicrobial effects of a cranberry marinade against Salmonella Typhimurium inoculated on chicken wings, and found consumer accepted the cranberry marinated chicken wings. We developed a sensitive real-time enrichment and detection system for viable Escherichia coli O157:H7 by a quartz crystal microbalance (QCM) with gold nanoparticles (AuNPs). The real-time foodborne pathogen detection method established in the study could be used to enrich and detect viable cells simultaneously, giving great potential for analysis of food samples. We developed a detection protocol for V. parahamolyticus based on an immunomagnetic separation (IMS) method using Pathatrix and Loop-mediated Isothermal Amplification (Lamp). The IMS Patharix method concentrated culture rapidly and reduced the enrichment time. The lamp detection method was convenient and has high specificity and sensitivity without expensive equipment. We studied the role of membrane disruption in the reduction of Escherichia coli O157:H7 by cranberry fractional components using a LIVE/DEAD viability assay in conjunction with viable cell counts. When comparing the relative intactness and viable cell counts, each fraction demonstrated a different pattern of inhibition We developed an integration of forced air cooling (FAC) and gaseous ClO2 sanitation systems as a second hurdle in post-processing to reduce microbial load on wild blueberries. In conjunction with various microbial reduction methods originally used in wild blueberry processing facilities, the combination of gaseous ClO2 treatment and FAC could be inexpensively adapted to commercial post-harvest processing of wild blueberries, providing a safer product with increased shelf life. We established a simple predictive model based on the correlation of catalase activity and viable microbial counts for celery, bell pepper and ready-to-eat salad (lettuce) and to verify the aforementioned model by random samples. The catalase assay is a simple, reliable and rapid way of detecting concentration of total microorganisms in vegetables tested. We investigated the natural antimicrobial activity of wild blueberries against H. pylori. The results indicate wild blueberries contain antimicrobial activity potential against H. pylori and have the potential to be used as a natural treatment option to H. pylori infections. We studied the antimicrobial properties of the lowbush blueberries against Escherichia coli O157:H7, and to determine the effects on growth inhibition, membrane permeability, and recovery. All fractions caused significant damage compared the control. We studied the prevalence of foodborne pathogens on lowbush blueberries. Our results showed that, no E. coli O157:H7 and L. monocytogenes were isolated from any of the 40 blueberry samples. Five samples from medium input, one sample from high input and one sample from organic input were Salmonella positive. The differences of fertilizers application may be the reason for contamination levels of Salmonella in the organic and medium input samples. We developed and determined the antimicrobial activity of edible films made with cranberries against foodborne pathogens, particularly Listeria monocytogenes and evaluate the application of edible cranberry films on deli ham. It was found that these two cranberry films drastically inhibited the growth of L. monocytogenes especially on slices of deli ham. We developed a rapid and specific optical sensing method for the detection of various STEC strains by DNA sandwich hybridization with oligonucleotide-functionalized AuNps. Results showed that color change can be visualized by the naked eye demonstrating direct and rapid detection of STEC strains through the specific target stx gene(s). This method requires less than one hour to complete after DNA sample preparation.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2015
Citation:
1. Juneja, V.K., S. Mukhopadhyay, D. Ukuku, C.-A. Hwang, V.C. H. Wu, H. Thippareddic. 2014. Interactive effects of
temperature, pH, and water activity on the growth kinetics of Shiga-toxin producing Escherichia coli O104:H4. J. Food
Prot. 77 (5): 706-712.
2. Wu, V.C.H.* and D.Y.C. Fung. 2014. Evaluation of the Thin Agar Layer Oxyrase� method for recovery of heat-Injured
foodborne pathogens in liquid media and food systems. J. Hum. Nutr. Food Sci. 2(2): 1027-1037.
3. Qiu, X. and V.C.H. Wu*, 2014. Antimicrobial effects of the combination of cranberry and wild blueberry extracts on
Escherichia coli O157:H7, Listeria monocytogenes, Salmonella Typhimurium, and Staphylococcus aureus. J. Adv. Food.
Tech. 1 (1): 101.
4. X. Shen, X., Sun, Q. Xie, H. Liu, Y. Zhao, Y. Pan, C.-A. Hwang, and V.C.H. Wu*. 2014. Antimicrobial effect of blueberry
(Vaccinium corymbosum L.) extracts against the growth of Listeria monocytogenes and Salmonella Enteritidis. Food
Control. 35: 159-165.
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
5. Lacombe, A., S. Tadepalli s, C.-A. Hwang, and V.C.H. Wu*. 2013. Phytochemicals in lowbush wild blueberry inactivate
Escherichia coli O157:H7 by damaging its cell membrane. Foodborne Pathogens and Disease. 10 (11): 944-950.
6. Lacombe, A., R.W. Li, D. Klims-Zacas, A.S. Kristo, S. Tadepalli s, E. Krauss, R. Young, and V.C.H. Wu*. 2013. Lowbush
wild blueberries have the potential to modify gut microbiota and xenobiotic metabolism in the rat colon. PloS One. 8
(6):e67497.
7. Tang, X., X. Sun, V.C.H. Wu, J. Xie, Y. Pan, Y. Zhao, and P.K. Malakar. 2013. Predicting shelf-life of chilled pork sold in
China. Food Control. 32: 334-340.
8. Davis, D, X. Guos, C.-S. Linc, , S.-H. Chens, and V.C.H. Wu*. 2013. Gold-nanoparticle-modified carbon electrode
biosensor for the detection of Listeria monocytogenes. Industrial Biotechnology. 6 (1): 31-36.
9. Lacombe, A., C. McGivneys, S. Tadepalli, X. Sun, and V.C.H. Wu*. 2013. The effect of American cranberry (Vaccinium
macrocarpon) constituents on the growth inhibition, membrane integrity, and injury of Escherichia coli O157:H7 and
Listeria monocytogenes in comparison to Lactobacillus rhamnosus. Food Microbiol. 34: 352-359.
10. Ma, Y.-J., X. Sun, Y. Zhao, Y. Lu, V.C.H. Wu, Y. Pan. 2013. REP-PCR and ERIC-PCR Analysis for the typing of Vibrio
parahaemolyticus isolated from sea products marketed in Shanghai. Food Sci. 34(10): 263-267.
11. Chen, Y., X. Sun, Y. Cao, Y. Zhao, V.C.H. Wu, and Y. Pan. 2013 Progress in antibacterial activity of blueberries.
Natural Product Research and Development. 25:716-721.
12. Liu, H., Y. Zhus, W. Jiangs, X. Sun, V.C.H. Wu, Y. Pan, Y. Zhao. 2013. Biotracing the source of Listeria
monocytogenes strains by enterobacterial repetitive intergenic consensus sequence-based PCR. Science and Technology
of Food Industry. 34(08): 49-51, 60.
13. Cao, Y., X. Sun, Y. Chens, Y. Zhao, V.C.H. Wu, and Y. Pan. 2013. Antibacterial effect of several extracts of
Dictyophora indusiata to bacteria common in food determined by micro?broth dilution method [J]. Science and Technology
of Food Industry. 34(07): 106-112.
14. Chen, Y., X. Sun, G. Sun, S. Ren, Y. Zhao, V.C.H. Wu, and Y. Pan. 2013. Analysis of the volatile chemical composition
of blueberry (Elliott) extracts by HS-SPME-GC-MS Method. Science and Technology of Food Industry. 34 (20): 78-81.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2014
Citation:
1. Quintela, I.s, B. G. de los Reyes, C.-S. Lin, and V.C.H. Wu*. 2014. Simultaneous direct detection of various shiga-toxin
producing Escherichia coli (STEC) strains by optical biosensing with oligonucleotide-functionalized gold nanoparticles
(AuNPs). Food Micro 2014. Nantes, France.
2. Wu, V.C.H.*, J. Shens, S.-H. Chens, and C.-S. Linc. 2014. An optical DNA sensing method for detection of Escherichia
coli O157:H7 using oligonucleotide-functionalized Au nanoparticles. International Association for Food Protection (IAFP)
European Symposium. Budapest, Hungary.
3. Wu, V.C.H.*, A. Lacombe, R. W. Li, D. Klimis-Zacas, A. S. Kristo, and S. Tadepalli. 2014. Functional food ingredients for
public health: Anthocyanin-rich lowbush wild blueberries have potential to modify gut microbiota and enhance xenobiotic
metabolism. The 15th International Conference of Functional Food Center. Regensburg, Germany.
4. Driver, R.s, I. Quintela s, B. G. de los Reyes, and V.C.H. Wu*. 2014. Development of a novel nano-optical system based
on nanotechnology and genome sequencing for comprehensive detection of Salmonella spp. Accepted for Institute of
Food Technologist Annual Meeting. New Orleans, LA.
5. Hallett, J.M.s, I.s Quintela, B. G. de los Reyes, and V.C.H. Wu*. 2014. Rapid detection of shiga-toxin producing
Escherichia coli (STEC) unamplified genomic DNA using oligonucleotide-functionalized gold nanoparticle (AuNP)
colorimetric assay. Accepted for Institute of Food Technologist Annual Meeting. New Orleans, LA.
6. Breards, A. C-A. Hwangc, D. Hill, X. Fan, L. Huang, and V.C.H. Wu*. 2014. Efficacy of peroxyacetic acid, lactic acid
chlorine dioxide, and chlorine washes on removal of Toxoplasma gondii from the surface of blueberries. Accepted for
Institute of Food Technologist Annual Meeting. New Orleans, LA.
7. Breards, A. C-A. Hwangc,, D. Hill, X. Fan, L. Huang, and V.C.H. Wu*. 2014. Developing a rapid colorimetric detection
method utilizing gold nanoparticles (AuNPs) for the detection of Toxoplasma gondii. Accepted for Institute of Food
Technologist Annual Meeting. New Orleans, LA.
8. Quintela, I.s, B. G. de los Reyes, C.-S. Lin, and V.C.H. Wu*. 2014. Direct and simultaneous detection of shiga-toxin
producing strains of Escherichia coli in ground beef and blueberry by gold nanoparticle optical sensing. Accepted for
Institute of Food Technologist Annual Meeting. New Orleans, LA.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2014
Citation:
9. Tadepalli, S., R. Driver, and V.C.H. Wu*. 2014. Evaluation of the effectiveness of different chemical sanitizers when
coupled with frozen storage in improving food safety of blueberries. Accepted for Institute of Food Technologist Annual
Meeting. New Orleans, LA.
10. Tadepalli, S., R. Driver, and V.C.H. Wu*. 2014. Evaluating the presence or absence of foodborne pathogens
associated with lowbush blueberries (Vaccinium angustifolium). Accepted for Institute of Food Technologist Annual
Meeting. New Orleans, LA.
11. Tadepalli, S., M. John, F. Drummond and V.C.H. Wu*. 2014. Evaluation of the level of wildlife fecal colonization by
Escherichia coli O157:H7 and the ecological role of dung beetles with the pathogen in blueberry farms. Accepted for
Institute of Food Technologist Annual Meeting. New Orleans, LA.
12. Zhu, Y., X. Sun, Y. Pan, and V.C.H. Wu*. 2014. Evaluation of chemical and sensory quality of twenty blueberry
cultivars in China. Accepted for Institute of Food Technologist Annual Meeting. New Orleans, LA.
13. Jiang, W., X. Sun, Y. Pan, and V.C.H. Wu*. 2014. Evaluation of antimicrobial and antioxidant properties of various
cultivars of blueberries obtained in China. Accepted for Institute of Food Technologist Annual Meeting. New Orleans, LA.
14. Yang, H., X. Sun, Y. Pan, and V.C.H. Wu*. 2014. Influence of Chinese wild blueberry on gut microbiota in high-fat dietinduced
mice. Accepted for Institute of Food Technologist Annual Meeting. New Orleans, LA.
15. Chen, Y., X. Sun, Y. Pan, and V.C.H. Wu*. 2014. The antimicrobial effects of the blueberry (Vaccinium spp.) extract
and fractional components against Vibrio parahaemolyticus. Accepted for Institute of Food Technologist Annual Meeting.
New Orleans, LA.
16. Chen, M., X. Sun, Y. Pan, and V.C.H. Wu*. 2014. Detection of detect toxigenic Vibrio parahaemolyticus using
immunomagnetic separation and duplex loop-mediated isothermal amplification. Accepted for Institute of Food
Technologist Annual Meeting. New Orleans, LA.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
17. Jones, M., F. Drummond*, V.C.H. Wu*, and S. Tadepalli. 2013. Suppression of the human pathogen, Escherichia coli
O157:H7, by dung beetles (Coleoptera: Scarabaeidae) using the lowbush blueberry (Vaccinium angustifolium)
agroecosystem as a conceptual model system. Entomological Society of America annual meeting. Austin, TX.
18. Lacombe, A., R. W. Li, D. Klimis-Zacas, A. S. Kristo, S. Tadepalli, E. Krauss, and V.C.H. Wu*. 2013. Anthocyanin-rich
lowbush wild blueberries have potential to modify gut microbiota and enhance xenobiotic metabolism in the rat colon.
Institute of Food Technologist Annual Meeting. Chicago, IL.
19. Quintela, I.s, B. G. de los Reyes, and V.C.H. Wu*. 2013. Direct detection of various shiga-toxin producing Escherichia
coli (STEC) strains by an optical sensing method using oligonucleotide-functionalized gold nanoparticles (AuNps). Institute
of Food Technologist Annual Meeting. Chicago, IL.
20. Tadepalli, S., T. Yu, and V.C.H. Wu*. 2013. The effect of chlorine (Cl2) and chlorine dioxide (ClO2) treatments
combined with frozen storage to prevent E. coli O157:H7 contamination on frozen processed wild blueberries. Institute of
Food Technologist Annual Meeting. Chicago, IL.
21. Wu, V.C.H., R. Youngs, A. Lacombe, C. Olsen, and T. McHugh. 2013. The antimicrobial effect of edible cranberry films
on the growth of Listeria monocytogenes. Institute of Food Technologist Annual Meeting. Chicago, IL.
22. Guos, X., C.-S. Linc,, S.-H. Chens, R.J. Yes, V.C.H. Wu*. 2013. A piezoelectic immunosensor for specific capture and
enrichment of viable Escherichia coli O157:H7 by quartz crystal microbalance sensor, followed by detection with antibodyfunctionalized
gold nanoparticles. International Association for Food Protection (IAFP) European Symposium. Marseille,
France.
23. Breards, A. C-A. Hwangc,, D. Hill, X. Fan, L. Huang, and V.C.H. Wu*. 2013. Efficacy of peroxyacetic acid and lactic
acid washes on removal of Toxoplasma gondii oocysts from blueberries. International Association for Food Protection
(IAFP) European Symposium. Marseille, France.
|
Progress 10/01/12 to 09/30/13
Outputs
Target Audience: Target audiences include fresh produce industry, professionals and scientists in the area of microbiology, food science, biotechnology, and food safety; the food industry; the general public and consumers. The results of projects are shared with the public and the food industry through extension and outreach activities, which benefit local, regional, and state agriculture and the food industry. The results of the projects are presented in national and international meetings, conferences, workshops, and published in scientific refereed journals. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? This project provided opportunities for training graduate students, research assistants, undergraduate and high school students. Students were able to present the research results at the international conferences. Several awards have been received through research competitions. How have the results been disseminated to communities of interest? Theresults of this study has been presented to the food industry. This study has been presented at international conferences such as International Association for Food Protection European Symposium and Institute of Food Technology (IFT) Annual Meetings. What do you plan to do during the next reporting period to accomplish the goals? The progress of this study is promising. We will continue on the two directions and finish the project
Impacts
What was accomplished under these goals?
This year we continued on developing biosensors and advanced methods to detect foodborne pathogens and studying antimicrobial mechanisms of cranberry components against foodborne pathogens. We developed a simultaneous enrichment and detection system for viable Escherichia coli O157:H7 on wild blueberries by a gold nanoparticles (AuNPs) functionalized quartz crystal microbalance (QCM). The results indicated a 133±35Hz decrease during BHI enrichment with the initial 2×101 CFU/ml of E. coli O157:H7 on blueberries whereas the negative controls showed only a 5±8Hz decrease. In addition, a significant frequency decrease of 93±24Hz (p<0.05) was observed after the addition of antibody-conjugated AuNPs, indicating the enriched bacteria captured on the QCM chip surface were actual E. coli O157:H7. The simultaneous enrichment and detection for E. coli O157:H7 established in the study could be used to detect viable bacteria at low concentration in food samples. The combination of both procedures in a nanoparticle-functionalized piezoelectric biosensor system indicates potential for the application of biosensors in real fields. We studied the antimicrobial properties of Maine wild blueberry fractional components against Listeria monocytogenes, Salmonella Typhimurium, and Lactobacillus rhamnosus in order to determine which components have antimicrobial effects and which types of microorganism are most susceptible. L. monocytogenes was the most susceptible to blueberry fraction treatment with the lowest MICs for F1 at 1.11g/L gallic acid equivalents (GAE), F2 1.00g/L GAE, F3 21.60mg/L cyanidin-3-glucoside equivalents (CGE), F4 17.40mg/L CGE, and F5 0.25 mM procyanidin-A2 equivalents. S. Typhimurium had the second lowest MICs with F1 at 2.23g/L GAE, F2 2.00g/ L GAE, F3 43.27mg/L CGE, F4 43.27mg/L CGE, and no MIC for F5. L. rhamnosus was the least susceptible to each fraction treatment with MICs of F1 at 2.23g/L GAE, F2 2.00g/L GAE, F3 43.27mg/L CGE, and no MIC for F4 an F5. Bactericidal concentrations were only observed for Salmonella and Listeria. Listeria demonstrated MBCs at F1 2.23g/L GAE, F2 2.00g/L GAE, F3 43.27mg/L CGE, F4 34.75mg/L CGE, and F5 0.25 mM procyanidin A2 eq. Salmonella demonstrated MBCs at F1 4.45g/L GAE, F2 2.00g/L GAE, F3 43.27mg/L CGE, and F4 69.50mg/L CGE. The study demonstrates effectiveness of blueberry antimicrobials against harmful microorganisms. The results of this study can be applied to the field of preventive medicine, food safety, and enrich the understanding of the health benefits of wild blueberries. We also investigate antimicrobial properties of American Cranberry (Vaccinium macrocarpon) components and determine which fraction(s) or combination of fractions gives cranberry its known antimicrobial effects and whether or not these properties affect probiotic organisms. For L. monocytogenes, the MIC of sugars plus organic acids (F1) was 5.2/1 Brix/acid, phenolics (F2) was 2.81g/L gallic acid equivalents (GAE), anthocyanins plus proanthocyanidins (F3) was 12.59mg/L cyanidin-3-glucoside equivalents (CGE), anthocyanins (F4) was 3.25mg/L CGE, and proanthocyanidins (F5) was 511.18 mM procyanidin-A2 equivalents. Phenolics (F2), anthocyanins plus proanthocyanidins (F3), and anthocyanins (F4) demonstrated bactericidal concentrations of 5.63g/L GAE, 25.18 mg/L CGE, and 12.98mg/L CGE, respectively. L. rhamnosus demonstrated MIC for phenolics (F2) at 11.25g/L GAE, anthocyanins plus proanthocyanidins (F3) at 25.2mg/L CGE, anthocyanins (F4) at 26mg/L CGE, and proanthocyanidins (F5) at 255.59 mM equivalents of procyanidin-A2. Sugars plus organic acids (F1) did not inhibit L. rhamnosus and a MBC was not achieved from any fraction at any concentration. Results from this study demonstrate a positive relationship between cranberry natural antimicrobial and probiotic bacteria as well demonstrating its effectiveness against harmful microorganisms. Information can be used to develop natural treatments against bacterial infection.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2012
Citation:
1. Guos, X., C.-S. Linc, , S.-H. Chens, R.J. Yes, and V.C.H. Wu*. 2012. A piezoelectic immunosensor for specific capture and enrichment of viable pathogens by the quartz crystal microbalance sensor, followed by detection with antibody-functionalized gold nanoparticles. Biosens. Bioelectron. 38: 177-183.
2. Lacombe, A.s, R.W. Li, D. Klims-Zacas, A.S. Kristo, S. Tadepalli s, E. Krauss, R. Young, and V.C.H. Wu*. 2012. Lowbush blueberries, Vaccinium angustifolium, modulate the functional potential of nutrient utilization and DNA repair mechanisms in the rat proximal colon microbiota. Functional Foods in Health and Disease. 2(6):228-241.
3. Zhang, H., L. Zhang, L.-J. Peng, X.-W., Dong, D. Wu, V.C.H. Wu, and P.-Q. Feng. 2012. Quantitative structure-activity relationships of antimicrobial fatty acids and derivatives against Staphylococcus aureus. J. Zhejiang Univ.-Sci. B (Biomed & Biotechnol). 13(2): 83-93.
4. Lacombe, A.s, V.C.H. Wu*, J. White s, S. Tadepalli s, and A. Enroe s. 2012. The Antimicrobial Properties of the Wild Blueberry (Vaccinium angustifolium) fractional components against foodborne pathogens and the conservation of probiotic Lactobacillus rhamnosus. Food Microbiol. 30: 124-131.
5. X. Sun, Q. Xu, Y. Pang, W. Lan, Y. Zhao, and V.C.H. Wu*. 2012. A loop-mediated isothermal amplification method for rapid detection of Vibrio parahaemolyticus in seafood. Annals of Microbiology. 62: 263-271.
6. Shen, X.s, X. Sun, Y. Zhao, Q.-C. Xie, V.C.H. Wu, and Y. Pan. 2012. The extracts of blueberries against growth of Staphyloccocus aureus. Nat. Prod. Res. Dev. 24(11): 1622-1625, 1599.
7. Xie, Q. s, X. Sun, X. Shen, V.C.H. Wu, and Y. Pan. 2012. Bacteriostasis effects of blueberries extracts on Vibrio parahaemolyticus. Nat. Prod. Res. Dev. 24:1094-1097, 1108.
8. He, J.-P.s, Y. Zhao, X. Sun, V.C.H. Wu, and Y. Pan. 2012. Antibacterial effects of burdock (Arctium Lappa L.) concentrate on Vibrio parahemolyticus. Nat. Prod. Res. Dev. 24: 381-384.
9. Su, C.s, X. Sun, Y. Lu, Y. Zhao, V.C.H. Wu, and Y. Pan. 2012. Preparation and application of Vibrio parahaemolyticus using immunomagnetic beads. Science and Technology of Food Industry . 33(17), 313-316.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2012
Citation:
1. Lacombes, A. and V.C.H. Wu*. 2012. Antimicrobial action of the American cranberry constituents at sub-lethal concentrations-examination of membrane stress mechanisms using fluorescence. II International Conference on Antimicrobial Research. Lisbon, Portugal.
2. Wu, Vivian C.H. 2012. Inhibitory effects of lowbush blueberries (Vaccinium angustifolium) against Helicobacter pylori. 10th International Symposium on Vaccinium and Other Superfruits. Maastricht, Netherlands.
3. Lacombe, A., R. W. Li, D. Klimis-Zacas, A. S. Kristo, S. Tadepalli, E. Krauss, and V.C.H. Wu*. 2012. Lowbush blueberries modulate the functional potential of the rat proximal colon microbiota. 2012. American Society for Microbiology Annual Meeting. San Francisco, CA.
4. Davis, D, X. Guo, and V.C.H. Wu*. 2012. Gold-nanoparticle-modified carbon electrode biosensor for the detection of Listeria monocytogenes. 2012. American Society for Microbiology Annual Meeting. San Francisco, CA.
5. Lacombe, A., S. Tadepalli, and V.C.H. Wu*. 2012. The Effect of Lowbush Blueberry (Vaccinium angustifolium) Constituents on the Growth Inhibition, Membrane Integrity, and Injury of Escherichia coli O157:H7. Institute of Food Technologist Annual Meeting. Los Vegas, NV.
6. Tadepalli, S. D. Davis, A. Lacombe, R. Young, and V.C.H. Wu*. 2012. Prevalence study of Escherichia coli O157:H7, Listeria monocytogenes and Salmonella spp. on Lowbush blueberries (Vaccinium angustifolium). Institute of Food Technologist Annual Meeting. Los Vegas, NV.
7. Liu, H., Y. Pan, and V.C.H. Wu*. 2012. Differentiation of serotypes of Listeria monocytogenes strains based on molecule tracing of complete gene sequencing. Institute of Food Technologist Annual Meeting. Los Vegas, NV.
8. Shen, X., Y. Pan, X. Sun, and V.C.H. Wu*. 2012. The Extracts of Four Chinese Blueberry Cultivars against Staphyloccocus aureus. Institute of Food Technologist Annual Meeting. Los Vegas, NV.
9. Xie, Q., X. Sun, Y. Pan, and V.C.H. Wu*. 2012. Antimicrobial effects of blueberry (Vacciniumcorymbosum L.) concentrate against Vibrio parahaemolyticus and its antimicrobial mechanism. Institute of Food Technologist Annual Meeting. Los Vegas, NV.
10. Ma, Y., X. Sun, Y. Zhao, Y. Liu, Y. Pan, and V.C.H. Wu*. 2012. Prevalence study of Vibrio parahaemolyticus isolated from shrimp in Shanghai. Institute of Food Technologist Annual Meeting. Los Vegas, NV.
|
Progress 10/01/11 to 09/30/12
Outputs
OUTPUTS: This year we continued on developing biosensors and advanced methods to detect foodborne pathogens and studying antimicrobial mechanisms of cranberry components against foodborne pathogens. We also developed interventions to control microbial contaminations. 1. We developed a sensitive real-time enrichment and detection system for viable Escherichia coli O157:H7 by a quartz crystal microbalance (QCM) with gold nanoparticles (AuNPs). 2. We developed a detection protocol for V. parahamolyticus based on an immunomagnetic separation (IMS) method using Pathatrix and Loop-mediated Isothermal Amplification (Lamp). 3. We studied the role of membrane disruption in the reduction of Escherichia coli O157:H7 by cranberry fractional components using a LIVE/DEAD viability assay in conjunction with viable cell counts. 4. We developed an integration of forced air cooling (FAC) and gaseous ClO2 sanitation systems as a second hurdle in post-processing to reduce microbial load on wild blueberries. 5. We established a simple predictive model based on the correlation of catalase activity and viable microbial counts for celery, bell pepper and ready-to-eat salad (lettuce) and to verify the aforementioned model by random samples. 6. We investigated the natural antimicrobial activity of wild blueberries against H. pylori. PARTICIPANTS: P.D.: Dr. Vivian C.H. Wu University of Maine Collaborators: Dr. Benildo G. de los Reyes, University of Maine Dr. Chich-Sheng Lin, National Chiao Tung University, Taiwan Xiaohong Sun, Shanghai Ocean University, China Ying-Jie Pan, Shanghai Ocean University, China Dr. Yong Zhao, Shanghai Ocean University, China Dr. Dorothy Klimis-Zacas, University of Maine Dr. Robert W. Li, USDA ARS. Graduate students: Alison Lacombe, Ph.D. in Food and Nutrition Sciences. UMaine. Sz-Hau Chen. Ph.D. in Biological Science and Technology, National Chiao Tung University, Taiwan. Xiao Guo, M.S. student in Food Science and Human Nutrition. UMaine. Haiquan Liu, Ph.D. student, Shanghai Ocean University. Xiaoyang Tang, M.S. student, Shanghai Ocean University. Y.-C. Chuang, Ph.D. in Biological Science and Technology, National Chiao Tung University, Taiwan. A. S. Kristo. Ph.D. in Food and Nutrition Sciences. UMaine. Staff: Shravani Tadepalli, Research Associate. University of Maine. Undergraduate students: Jeremiah Antosch. Microbiology. UMaine. Jenni White. Biochemistry. UMaine. Andy Arguello Marin. Microbiology. UMaine. Christine McGivney, Biology. UMaine. E. Krauss. Food Science and Human Nutrition. UMaine. High School Students: Becky Ye, Bangor High, Maine. TARGET AUDIENCES: Target audiences include fresh produce industry, professionals and scientists in the area of microbiology, food science, biotechnology, and food safety; the food industry; the general public and consumers. The results of projects are shared with the public and the food industry through extension and outreach activities, which benefit local, regional, and state agriculture and the food industry. The results of the projects are presented in national and international meetings, conferences, workshops, and published in scientific refereed journals. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
1. Significant frequency changes observed using the second antibody-AuNPs. In addition, 0 log CFU/mL of E. coli O157:H7 were detected after injection of BHI broth whereas generic E. coli showed no significant frequency changes after BHI circulation. The real-time foodborne pathogen detection method established in the study could be used to enrich and detect viable cells simultaneously, giving great potential for analysis of food samples. 2.Results showed that larger beads enriched more V. parahaemolyticus at 37C during 30 min Pathatrix circulating enrichment. The detection limit of 2log cfu/mL was obtained for IMS Patharix in conjunction with Lamp. The IMS Patharix method concentrated culture rapidly and reduced the enrichment time. The lamp detection method was convenient and has high specificity and sensitivity without expensive equipment. This detection protocol based on IMS in conjunction with Lamp can be applied in the food industry. 3.When comparing the relative intactness and viable cell counts, each fraction demonstrated a different pattern of inhibition. The results explicate the individual roles that fractional components have in the antimicrobial mechanism and develop the possibilities of natural antimicrobials for further applications.. 4.The developed post-treatment had reduction values of 0.89-1.20 CFU/g, with different reduction levels observed for slightly different sample positions within the pallet. Visual quality of the blueberries was not significantly affected by gaseous ClO2 treatment. In conjunction with various microbial reduction methods originally used in wild blueberry processing facilities, the combination of gaseous ClO2 treatment and FAC could be inexpensively adapted to commercial post-harvest processing of wild blueberries, providing a safer product with increased shelf life.. 5.It was found that the catalase activity in the sample is positively correlated to the log concentration of bacteria and fungi. The catalase activity assay appears to be a fairly effective method for rapid assessment of microbial contamination on vegetables tested. The model based on the correlation between catalase activity and microbial loads was established and tested, with results that show accuracy of prediction at higher levels of contamination. The catalase assay is a simple, reliable and rapid way of detecting concentration of total microorganisms in vegetables tested. It may have potential utility in a school cafeteria setting, or any other place with ready-to-eat foods. 6.Both wild blueberry powders significantly (p<0.05) inhibited the growth of H. pylori in the agar diffusion assay. Concentrates between 25%-12.5% showed to be the minimum inhibition concentration required for H. pylori inhibition. The likely mode of action may be through inhibition at the plasma membrane level in the production of biofilm by H. pylori. The present study indicates wild blueberries contain antimicrobial activity potential against H. pylori and have the potential to be used as a natural treatment option to H. pylori infections.
Publications
- Ye, R. J.s and V.C.H. Wu. 2011. Use of a simple catalase assay for assessment of aerobic microbial contamination on vegetables. Ann. Microbiol. 61: 231-236.
- Wu, V.C.H. 2011. Detection of stressed foodborne microorganisms by conventional and innovative methods. In: Stress Responses in Foodborne Microorganisms. Editor: H.-C. Wong. Nova Publisher, Inc., Hauppauge NY.
- Liu, H.-Q., X. Shen, V.C.H. Wu, Y. Pan, and X. Sun. 2011. Progresses of rapid detection technique for Listeria monocytogenes. Hunan Agricultural Sciences. 1: 1-3.
- He, J.-P., Y. Zhao, X. Sun, V.C.H. Wu, X. Tang, and Y. Pan. 2011. Application of burdock peel concentrate to control microbiologsy in pork. Transactions of the Chinese Society of Agricultural Engineering. 27(s2): 242-246.
- Lacombe, A., R. W. Li, D. Klimis-Zacas, A. S. Kristo, S. Tadepalli, E. Krauss, and V.C.H. Wu*. 2011. The effect of lowbush blueberry-enriched diets on the microbial composition of the rat proximal colon detected by metagenomics. 2011. 46 American Society for Microbiology Annual Region I Meeting. Randolph, MA.
- Davis, D. X. Guo, and V.C.H. Wu. 2011. Gold-nanoparticle-modified carbon electrode biosensor for the detection of Listeria monocytogenes. 46 American Society for Microbiology Annual Region I Meeting. Randolph, MA.
- Lacombe, A. V.C.H. Wu, R. W. Li, S. Tadepalli, E. Krauss, , A. S. Kristo, and D. Klimis-Zacas. 2011. Dietary effects of lowbush blueberries (Vaccinium angustifolium) on the gut microbiome using a rat Model. American Society for Microbiology Annual Meeting. New Orleans, LA.
- Guo, X., C.S. Lin, Y.-C. Chuang, S.-H. Chen, R. Ye and V.C.H. Wu. 2011. Simultaneous enrichment and detection of viable E. coli O157:H7 inoculated on wild blueberries by a nanoparticle-functionalized piezoelectric biosensor. Institute of Food Technologist Annual Meeting. New Orleans, LA.
- Lacombe, A., J. White, S. Tadepalli, E. Andre and V.C.H. Wu. 2011. The Antimicrobial Properties of the Wild Blueberry (Vaccinium angustifolium) fractional components against foodborne pathogens and the conservation of probiotic Lactobacillus rhamnosus. Institute of Food Technologist Annual Meeting. New Orleans, LA.
- Lacombe, A., C. McGivney, and V.C.H. Wu. 2011. Antimicrobial Action of the American Cranberry (Vaccinium macrocarpon) Fractional Components against Listeria monocytogenes and the Conservation of Lactobacillus rhamnosus. Institute of Food Technologist Annual Meeting. New Orleans, LA.
- Liu, H.-Q., Q. Zhao, Y. Zhao, Y.-J. Pan, X. Sun, and V.C.H. Wu. 2011. Investigation of antibacterial activity of three Chinese spices against Vibrio parahaemolyticus and Listeria spp. Institute of Food Technologist Annual Meeting. New Orleans, LA.
- Shen, X., Y.-J. Pan, X. Sun, and V.C.H. Wu. 2011. Investigation of antimicrobial effects of blueberries (Vaccinium corymbosum L) cultivated in China against Listeria monocytogenes. Institute of Food Technologist Annual Meeting. New Orleans, LA.
- Xie, Q., Y.-J. Pan, X. Sun, and V.C.H. Wu. 2011. Comparison of inhibitory effects of blueberries (Vaccinium corymbosum L.) on Vibrio parahaemolyticus by different extraction conditions. Institute of Food Technologist Annual Meeting. New Orleans, LA.
- Su, C.-X., Y.-J. Pan, Y. Zhao, X. Sun, and V.C.H. Wu. 2011. Detection of Vibrio parahaemolyticus using immunomagnetic beads of different antibody conjugating chemistry and loop-mediated isothermal amplification. Institute of Food Technologist Annual Meeting. New Orleans, LA.
- Ma, Yuejiao, X. Sun, Y. Zhao, V.C.H. Wu and Y. Pan. 2011. Detection and molecular characterization of Vibrio parahaemolyticus isolated from seafood in Shanghai. Institute of Food Technologist Annual Meeting. New Orleans, LA.
|
Progress 10/01/10 to 09/30/11
Outputs
OUTPUTS: This year we focused on developing biosensors to detect foodborne pathogens and studying antimicrobial mechanisms of cranberry components against foodborne pathogens. We also exanimated the application of natural antimicrobials in food. 1. We developed a real-time enrichment and detection system for viable Escherichia coli O157:H7 and Listeria monocytogenes by a piezoelectric biosensor quartz crystal microbalance (QCM). 2. We developed a biosensing method based on aggregation of oligonucletide-functionalized gold nanoparticles (AuNPs) due to sandwich hybridization of probes and the complementary target sequence for the detection of E. coli O157:H7 by naked eyes. 3. We investigated what bioactive compounds in cranberries are majorly responsible for the antimicrobial activity of cranberries against foodborne pathogens, particularly Escherichia coli O15:H7. 4. We developed chitosan films containing cranberry concentrate and tested for antibacterial activity on poultry drumsticks over a period of 5 days. 5. We studied the antimicrobial effects of a cranberry marinade against Salmonella Typhimurium inoculated on chicken wings, and the consumer acceptability of cranberry marinated chicken wings. The results of projects conducted in this period are shared with the public through extension and outreach activities, which benefit local, regional, and state agriculture and the food industry. The results of the projects have also been presented in national and international meetings, shared in international workshops, and published in scientific refereed journals. PARTICIPANTS: P.D.: Dr. Vivian C.H. Wu University of Maine Collaborators: Dr. Benildo G. de los Reyes, University of Maine Dr. Seth Tyler, University of Maine Kelly Edwards, University of Maine Dr. Chich-Sheng Lin, National Chiao Tung University, Taiwan Xiaohong Sun, Shanghai Ocean University, China Ying-Jie Pan, Shanghai Ocean University, China Dr. Yong Zhao, Shanghai Ocean University, China Graduate students: Alison Lacombe, Ph.D. in Food and Nutrition Sciences. UMaine. Sz-Hau Chen. Ph.D. in Biological Science and Technology, National Chiao Tung University, Taiwan. Xiao Guo, M.S. student in Food Science and Human Nutrition. UMaine. Jingjing Shen, M.S. student in Food Science and Human Nutrition. UMaine. Amanda Rioux, M.S.student in Food Science and Human Nutrition. UMaine. June Garrett, M.S. in Food Science and Human Nutrition. UMaine. Haiquan Liu, Ph.D. student, Shanghai Ocean University. Xiaoyang Tang, M.S. student, Shanghai Ocean University. Y.-C. Chuang, Ph.D. in Biological Science and Technology, National Chiao Tung University, Taiwan. Undergraduate students: Jeremiah Antosch. Microbiology. UMaine. Jenni White. Biochemistry. UMaine. Andy Arguello Marin. Microbiology. UMaine. TARGET AUDIENCES: Target audiences include fresh produce industry, professionals and scientists in the area of microbiology, food science, biotechnology, and food safety; the food industry; the general public and consumers. The results of projects are shared with the public and the food industry through extension and outreach activities, which benefit local, regional, and state agriculture and the food industry. The results of the projects are presented in national and international meetings, conferences, workshops, and published in scientific refereed journals. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
1. The real-time enrichment and detection of target pathogens using the QCM system designed were very sensitive with a detection limit of 60 and 84 CFU/ml for E. coli O157:H7 and L. monocytogenes, respectively. Significant frequency changes (P < 0.05) observed during the circulation indicated successful enrichment and detection of the target bacteria. In contrast, generic E. coli showed no significant frequency change after injection of the BHI broth. The real-time biosensor detection established in our study could be used to enrich and detect viable cells simultaneously, giving great potential for pathogenic analysis when the system is applied in food samples. 2. It was found that the AuNPs sandwich hybridization method was very specific for E. coli O157:H7 only. The AuNPs sandwich hybridization assay optimized can be used as a rapid, inexpensive and highly specific detection method for E. coli O157:H7 without needing an optical instrument. 3. The results indicated that each fraction showed significant antimicrobial effects (P < 0.05) compared to the control (0%) at 24h. At 50% v/v concentration sugars plus organic acids demonstrated 9 log CFU/ml reduction, phenolic demonstrated 3 log reduction, and anthocyanins demonstrated 9 log reduction. Compared to the initial inoculation at 0h, sugars plus organic acid (25%) and anthocyanins (25%) demonstrated significant reduction after 24 hours to 2 and 2.5 log CFU/ml, respectively. For the concentration of 50%, bacteria were not detectable for both sugar plus organic acid and anthocyanins after 24h. 4. The addition of chitosan films both with and without cranberry concentrate significantly inhibited (P< 0.05) S. Typhimurium inoculated on the surface of the chicken drumsticks. Chicken treated with these films was found to visually resemble untreated chicken, whilst high cranberry concentration treatment of chicken with only cranberry concentrate and no chitosan film resulted in discoloration. Due to the antibacterial nature of these films, they present themselves as an effective means of naturally treating poultry with cranberry in a manner that does not cause aesthetic detriment to the product. 5. Chicken wings marinated with original and double concentrations of cranberry sauce had 1.18 and 1.5 log CFU/g reductions of S. Typhimurium, respectively, while the hot sauce only marinade did not cause any reduction. Sensory evaluation showed the original and the double concentrated cranberry marinade had no significant differences from each other in appearance and flavor, and they have higher scores (P<0.05) than the hot sauce only marinade and the control. Texture and overall acceptability ratings of the original cranberry marinated chicken wings were the highest among the other treatments and the control (P<0.05). Considering the antimicrobial effects and health benefits of cranberries, cranberry marinated chicken wings may be a potential safe and healthy product preferred by consumers.
Publications
- Lacombe, A., V.C.H. Wu*, S. Tyler, and K. Edwards. 2010. Antimicrobial action of the American cranberry constituents, phenolics, anthocyanins, and organic acids, against Escherichia coli O157:H7. Int. J. Food Microbiol. 139:102-107.
- Wu, V.C.H.* and A. Rioux. 2010. A simple instrument-free gaseous chlorine dioxide method for microbial decontamination of potatoes during storage. Food Microbiol. 27: 179-184.
- Wu, V.C.H. 2010. Detection of stressed foodborne microorganisms by conventional and innovative methods. In: Stress Responses in Foodborne Microorganisms. Editor: H.-C. Wong. Nova Publisher, Inc., Hauppauge NY.
- He, J.-P., S. Liang, Y. Zhao, X.-H. Sun, V.C.H. Wu, and Y.-J. Pan. 2010. Study on anti-oxidative activity and antibacterial effect of extracts from Arctium lappa L. Science and Technology of Food Industry. 6(31):131-133.
- Tang, X.-Y, Y. Zhao, X.-H. Sun, V.C.H. Wu, and Y.-J. Pan. 2010. Establishment and validation of predictive model of Pseudomonas spp. Hunan Agricultural Sciences. 1:128-134.
- Liu, H.-Q., Q. Zhao, X.-H. Sun, V.C.H. Wu, Y.-J., Pan, and Y. Zhao. 2010. Rapid detection of Listeria monocytogenes in food by multiple PCR. Scientia Agricultura Sinica. 23(43):4893-4900.
- Guo, X., C.S. Lin, Y.-C. Chuang, S.-H. Chen, R. Ye and V.C.H. Wu*. 2010. Real Real-time detection of viable E. coli O157:H7 on a piezoelectric biosensor with the amplification of antibody-conjugated gold nanoparticles. Institute of Food Technologist Annual Meeting. Chicago, IL.
- V.C.H. Wu* and J.G. Antosch. 2010. Integration of forced air cooling and gaseous chlorine dioxide sanitization of wild blueberries. Institute of Food Technologist Annual Meeting. Chicago, IL.
- Lacombe, A. and V.C.H. Wu*. 2010. The Antimicrobial Action of the American Cranberry Fractional Components against Escherichia coli O157:H7 and determination of membrane permeability. Institute of Food Technologist Annual Meeting. Chicago, IL.
- X. Wu, X. Sun, and V.C.H. Wu*. 2010. Rapid Detection of Vibrio parahaemolyticus using Immunomagnetic Separation and Loop-mediated Isothermal Amplification Assay. Institute of Food Technologist Annual Meeting. Chicago, IL.
- V.C.H. Wu*, A.E. Arguello Marin, and J. K. Garrett. 2010. Inhibitory effects of wild blueberries against Helicobacter pylori. Institute of Food Technologist Annual Meeting. Chicago, IL.
- White, J. L., A. Lacombe, and V. C. H. Wu*. 2010. Antimicrobial properties of Maine wild blueberries. American Society for Microbiology Annual Meeting. San Diego, CA.
|
Progress 10/01/09 to 09/30/10
Outputs
OUTPUTS: This year we focused on developing biosensing method based on nanotechnology to detect foodborne pathogens and intervention methods to reduce microbial contamination associated with fresh produce and studying antimicrobial mechanisms of cranberry concentrate on molecular level. We also exam the application of natural antimicrobials in food using sensory analysis. 1. We developed a label-free DNA based colorimetric method based on AuNPs sandwich hybridization for rapid detection of E. coli O157:H7. 2. We developed a novel, simple gaseous chlorine dioxide (ClO2) method that could effectively control microorganisms on potatoes during storage. 3. We develop a simple gaseous chlorine dioxide (ClO2) method for disinfection of spinach and blueberries using bag approach. 4. We investigate the antimicrobial effect of cranberry concentrate (Vaccinium macrocarpon) on Escherichia coli O157:H7 on the gene regulation level. 5. As synergistic antimicrobial effects of cranberries and wild blueberries on foodborne pathogens were discovered in our previous study, hence, we investigated if burgers supplemented with the berry concentrate mixture could be accepted by panelists using a hedonic test. The results of projects conducted in this period are shared with the public through extension and outreach activities, which benefit local, regional, and state agriculture and the food industry. The results of the projects have also been presented in national and international meetings, shared in international workshops, and published in scientific refereed journals. PARTICIPANTS: P.D.: Dr. Vivian C.H. Wu University of Maine Collaborators: Dr. Benildo G. de los Reyes, University of Maine Dr. Chich-Sheng Lin, National Chiao Tung University, Taiwan Graduate students: Xujian Qiu, Ph.D. in Food and Nutrition Sciences. UMaine. Sz-Hau Chen. Ph.D. in Biological Science and Technology, National Chiao Tung University, Taiwan. Amanda Rioux, M.S. in Food Science and Human Nutrition. UMaine. Jingjing Shen, M.S. student in Food Science and Human Nutrition. UMaine. Laura Harper, M.S. student in Food Science and Human Nutrition. UMaine. Undergraduate students: Molly Principe. Microbiology. UMaine. Laura Harper. Biochemistry. UMaine. Jason Gilbert. Microbiology. UMaine. TARGET AUDIENCES: Target audiences include fresh produce industry, professionals and scientists in the area of microbiology, food science, biotechnology, and food safety; the food industry; the general public and consumers. The results of projects are shared with the public and the food industry through extension and outreach activities, which benefit local, regional, and state agriculture and the food industry. The results of the projects are presented in national and international meetings, conferences, workshops, and published in scientific refereed journals. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
1. Thiol modified probes had greater immobilization efficiency than the probes without thiol modification. Sandwich hybridization occurred between the target sequence and AuNPs-DNA probes at temperature close to melting temperature of the probes. In addition, the control of salt concentration plays an important role in hybridization. AuNPs sandwich hybridization controlled by temperature and high concentration of salt solution can be used as a rapid, simple, and inexpensive detection method for E. coli O157:H7 and the result can be read by eyes without any optical equipment. 2. Results were effective for yeasts and molds, showing over a 5 log CFU/potato reduction with a 4g treatment after 5 hr. The natural microbiota study also showed over a 5 log CFU/potato reduction. For P. aeruginosa, there was a slight increase in the reduction after 5 hr of the 4g treatment with almost a 6 log CFU/potato reduction. Gaseous ClO2 did not affect the overall visual quality of the potato. The residue of ClO2 decreased to < 1mg/l after 14 days consistently for each treatment. Gaseous ClO2 may be scaled up to help potato farmers to grow and prosper without having to deal with the loss of their crops in storage due to microbial contamination. 3. Results were effective for decontamination of E. coli O157:H7 on spinach using the slow release, showing a 3.4 log CFU/g reduction. The low concentration of ClO2 over 7 days did not affect visual quality of spinach leaves. For blueberry study using the fast release, a 5.86 log CFU/g reduction was achieved with 3g, 5hr treatment. Gaseous ClO2 did not affect the overall visual quality of blueberries. This simple method can easily be incorporated into the existing process and provide advantages to producers who wish to preserve the appearance of their sanitized produce. 4. The gene expression levels of the examined genes in E. coli O157:H7 were significantly altered by the cranberry concentrate. Compared to the control samples, genes of slp, hdeA, and cfa were markedly downregulated (P < 0.05), ompC was slightly down regulated, while osmY was slightly affected. The results suggest that the effects of cranberry concentrate on the growth inhibition of foodborne pathogens as previously discovered may be at the molecular level rather than only physical damage. Based on the inhibition of growth-related genes shown in the study and our previous viable cell and ultrastructural analysis, the cranberry concentrate studied is proven as an antimicrobial agent. 5. Results showed burgers with 2.5% and 5% had no significant differences from control burgers (0% berry concentrate mixture) in appearance, flavor, and texture, and overall acceptability. There was no significant difference in texture for all four samples. No difference was found among 0%, 2.5% and 5% burgers for flavor. Burgers with 7.5% cranberry concentrate had a slightly lower score (6.21) than other samples for flavor. Burgers with the cranberry and blueberry concentrate mixture (2.5%) had the highest score (7.26) and were liked moderately by panelists. Burgers supplemented with the berry mixture may be a potential safe and healthy product preferred by consumers.
Publications
- * Wu, V.C.H.*, X. Qius, B. de los Reyesc, C.S. Linc, and Y.J. Panc. 2009. Application of cranberry concentrate (Vaccinium macrocarpon) to control Escherichia coli O157:H7 in ground beef and its antimicrobial mechanism related to the downregulated slp, hedeA and cfa. Food Microbiol. 26: 32-38.
- Guo, X.s, S.-H. Chens, C.S. Linc, and V.C.H. Wu*. 2009. Real-time detection of viable foodborne pathogens by a piezoelectric biosensor. Institute of Food Technologist Annual Meeting. Anaheim, CA.
- V.C.H. Wu*, W. Traina, and X Qiu. 2009. Control of Salmonella on poultry products with cranberry concentrate chitosan films. Institute of Food Technologist Annual Meeting. Anaheim, CA.
- Lacombe, A.s and V.C.H. Wu*. 2009. Investigation of the Antimicrobial Effect of Constituent Cranberry Components against Escherichia coli O15:H7. Institute of Food Technologist Annual Meeting. Anaheim, CA.
- V.C.H. Wu*, L. Boutet, and X Qiu. 2009. Safe and delicious cranberry marinated chicken wings. Institute of Food Technologist Annual Meeting. Anaheim, CA.
- Shen, J.s, S.-H. Chens, C.S. Linc, and V.C.H. Wu*. 2009. A novel gold nanoparticle sandwich hybridization assay for rapid detection of Escherichia coli O157:H7. Institute of Food Technologist Annual Meeting. Anaheim, CA.
|
|