Novel Detection Methods in Food Safety

 

This topic was moderated by Hau-Yang Tsen, Ph.D. and Vivian Chi-Hua Wu, Ph.D. and featured five lectures.

 

Chien-Shun Chiou, Ph.D., Principal Investigator, Head of Central Regional Laboratory, Center for Research and Diagnostics, Centers for Disease Control, Taiwan discussed the development and application of molecular subtyping methods to surveil Salmonellosis in Taiwan, and shared findings that provided insight and understanding into an international salmonellosis outbreak through infant milk formula and accumulated large amount of PFGE and AST data that are useful in tracking the principal reservoirs for human salmonellosis and predicting Salmonella serotypes. Through the comparison of PFGE patterns with those in the database, findings indicated that pig is a principal reservoir for human salmonellosis in Taiwan and successfully predicted the serotypes for 99.4% of 862 Salmonella isolates collected in 2012.

 

Yao-Wen Huang, Ph.D., Professor, University of Georgia, USA discussed rapid detection of pathogens and toxins in the food system using surface-enhanced Raman spectroscopy (SERS) with silver nanorod array substrates. Dr. Huang noted that the use of aligned silver nanorod (AgNR) arrays prepared by oblique angle deposition (OAD), as surface-enhanced Raman scattering (SERS) substrates to detect food safety related substances such as foodborne pathogens, toxins, pesticides, and adulteration agents. Six foodborne pathogenic bacteria including Salmonella enterica serotype Anatum, S. enterica serotype Cubana, S. enterica serotype Stanley, S. enteritidis, E. coli O157:H7 and S. epidermidis in mung bean sprouts were detected using functionalized substrates with vancomycin. Dr. Huang shared that the results show bacterial species and serotypes can be detected and differentiated at the limit of 100cfu/ml within four hours.

 

Vivian Chi-Hua Wu, Ph.D., Associate Professor, Department of Food Science & Human Nutrition, University of Maine, USA discussed pathogen detection using biosensors and nanotechnology, and noted that a variety of rapid methods have been developed to detect and screen foodborne pathogens. These methods include antibody-based methods, such as immunofluorescence, immunoimmobilization, enzyme-linked immunosorbent assay, immunomagnetic separation, and nucleic acid-based methods such as hybridization and polymerase chain reaction [PCR], as well as biochemical and enzymatic methods such as miniaturized microbiological methods and commercial miniaturized diagnostic kits.

 

Hua-Yang Tsen, Ph.D., Professor and Dean, College of Human Ecology, Hungkuang University, Taiwan gave a presentation entitled, “Development and Use of Molecular Methods for the Detection of Food Pathogens, Virus, and Biological Species in Foods.” Dr. Tsen discussed various molecular detection techniques, such as polymerase chain reaction (PCR), multiplex PCR, DNA probes and biochips, real-time PCR (Q PCR), reverse transcription (RT) Q PCR, and insulated isothermal PCR (ii PCR), specific for the detection of different bacteria or biological species. Dr. Tsen noted that certain techniques have been established in order to trace the contamination origins of pathogenic strains and to conduct epidemiological study, including genotyping techniques such as PFGE, RAPD, MLST.

 

Tzann-Feng Lin, Ph.D., President, TTL, Taipei, Taiwan discussed systematic quality detection for functional foods, using the example of Monascus products. Dr. Lin shared study conclusions that Monascus TTL-123 is a suitable source ingredient for the production of Monascus health products, and emphasized that standardized safety analysis methods and understanding of functionality and beneficial effects are required for quality control of functional food products.