J. David Legan, PhD
Director of Science
David earned his Ph.D. in Food Technology from the University of Reading in the UK by modeling the ecology of mixed microbial populations, and then moved to Campden BRI in a variety of microbiological food safety research and client service roles. During that time, he was project lead for the Bacillus component of the UK’s pathogen modeling program. He moved again to Nabisco Research in New Jersey where he ran the corporate microbiology lab and developed a program of preservation technology development and microbial modeling. After the Kraft Foods acquisition, he moved to Chicago to work on Food Safety and Preservation research, and through modeling and validation studies:
- Optimized Oscar Mayer’s use of lactate and diacetate and their naturally cultured alternatives as Listeria-control agents in Ready to Eat meats
- Specified process conditions central to Oscar Mayer’s commercial launch of High Pressure Pasteurization of naturally cured RTE meats
David had responsibility for the Kraft cultures R&D group, developed a partnership to explore microwave sterilization leading to several patents, and led a program that developed an internal proprietary natural antimicrobial commercialized in several Kraft products. Technologies from his group supported approximately $4 billion in annual sales.
After years as a microbiology "client", he is now back in the "provider" role as Director of Science at Eurofins Microbiology Laboratories, Inc., by way of the Covance Food Solutions group based in Madison, WI, which he joined in 2016. In this role, he ensures appropriate method validation, explores new testing technologies, and fields multiple complicated food microbiology questions.
Products that his team has evaluated or developed and launched include:
- The 3M MDS platform in the Madison microbiology laboratory
- Flow cytometry for enumeration of probiotics
- Strain-level confirmation of probiotic identification using the polymerase chain reaction (PCR)
- Next-generation sequencing using the Oxford Nanopore Technologies GridION sequencing platform for microbial identification and microbiome analysis
Below are resources from David:
Food safety risks in fruit and vegetable processing environments can come from many different sources. Agricultural items are inherently dirty products, which can introduce risk- including microbial pathogens- to a facility from the outside environment. If your Environmental Monitoring Program (EMP) and sanitation programs are not sufficient to control these risks, these products could be potentially cross contaminating other products that are subsequently processed in the facility. It is therefore imperative that we think about risks from both our incoming products and our processes when designing environmental monitoring programs.
Non-culturable presumptive (NCP)- samples that yield positive pathogen detection results by PCR screening methods but do not confirm by cultural methods- can be frustrating and disruptive to clients. These situations are not unique to a testing company or the methods that are run, but it is possible to understand the root causes of NCPs, and to identify additional procedures to reduce the frequency with which they occur and minimize the likelihood of these situations impacting your data.
When you submit a sample to the laboratory for microbiology testing, what happens? Follow a Listeria spp. sample through the lab workflow in this infographic.
The demand for low- and non-alcoholic beverages is booming, driven by evolving consumer preferences for healthier, more mindful drinking options. But behind this innovation lies a complex challenge: without alcohol’s natural antimicrobial properties, these beverages face a higher risk of spoilage and contamination. Ensuring product safety, shelf stability, and regulatory compliance requires more than careful brewing—it calls for the expertise of a qualified process authority. Here is a look at the key risks, essential testing protocols, and proven strategies to keep your low- and no-alcohol products safe, high-quality, and market-ready.
In this on-demand webinar about controlling listeria, Dr. Douglas Marshall discusses some common sampling and testing practices and highlight risks associated with their use. Original Air Date: January 22, 2025.
This article describes the basics of flow cytometry in its application to probiotic enumeration, including a comparison between flow cytometry and traditional plate count methods, afu vs cfu, advantages and disadvantages of flow cytometry, marketplace examples and investigative case studies.
The effectiveness of a preservative or antimicrobial product is critical in ensuring the safety of a food product and extending its shelf life. This article helps you to understand the basic considerations of preservative and antimicrobial efficacy testing, including determining a minimum inhibitory concentration (MIC), giving you the background needed to select the best test methods for your food product evaluation.
In this on-demand webinar Doug Marshall and John Scanga explain the latest regulatory challenges in food safety and quality from the FDA and USDA with a focus on the new rules and regulations. Original airdate August 7, 2024.
This poster evaluates the microbiological safety of immersion method concentrated coffee, and single strength cold brew coffee processed by UHT. The results were used to determine if temperature controls for safety (TCS) should be required for these products during retail.
This poster discusses research with the purpose to validate enrichment concentration as a method for shortening enrichment times to 12 hours for Listeria testing in leafy greens.
