Direct Detection of Salmonella on Fresh Produce

This paper presents a method of bacterial detection that directly detects and quantifies the presence of specific bacteria on the surfaces of fresh produce without sample preparation (water rinse, soak, stomaching, etc.) and/or enrichment. The method combines wireless magnetoelastic (ME) biosensors and a surface-scanning detector for the swift screening of foods. Tests were conducted on tomatoes spiked with difference concentrations of Salmonella Typhimurium as a model pathogen. The speed of detection was from 2 to 10 minutes with a limit of detection (LOD) in a range of 102 to 104 cfu/mm2. The current LOD can be improved by using smaller, more sensitive ME biosensors (sub-millimeters in length) with an appropriate quantity. The presented method can be used on site for food inspection and outbreak investigation.