Microbiological Safety Challenges in Plant-Based Meats

AT: Operating as an AOAC validation lab allows us to help and support the food industry in unique and impactful ways. The work that we helped Bio-Rad with on the plant-based meat product study was the Independent Laboratory portion that included a matrix study, to provide data to be used to support the addition of plant-based meat on the PTM certificate for the iQ-Check Salmonella Test Kit.

AT: The matrix that we used, while novel, did not pose specific analytical challenges while performing this study. In preparation, it was relatively indistinguishable from traditional, or animal-based ground meat products. Because there is a lot of variety in novel plant-based meat products, understanding each product type’s unique challenges would be beneficial when confirming that a test kit is fit for purpose for a specific application.

AT: While there should be regulatory requirements in place around this type of commodity to protect consumer health and safety, the microorganisms of concern may be different in a plant-based product than a traditional animal-based meat product. Also, the way the plant-based product is manufactured and processed should be considered in the implementation of regulatory requirements, as those factors will impact which organisms of concern are in a final product.

AT: As consumer acceptance of this type of product increases, and more variety is seen in this space, we will be able to learn more about the unique challenges that plant-based meat products pose, both from a consumer standpoint, as well as the individual microbial risks of different production and manufacturing processes. Novel products on the market are always a fun and exciting thing to experience, as the industry learns so much as the segment grows.

MC: Unfortunately, this is a complicated answer as there is no harmonised view for these types of products. For example, Health Canada clearly places ‘meat substitutes’ in the ‘fruit and vegetable-based products’ category, hence they are a ‘raw and raw processed’ food type. For AOAC, these types of products are not referenced in any guidance documents and are currently being considered as their own category. For validation bodies that measure against ISO 16140, such as AFNOR, these types of matrices are also not included in Annex A of ISO 16140 Part 2. At the AFNOR level, these types of foods, which also include other types of alternative proteins, are considered as novel foods and a working group has been opened to define the scope and to consider the challenges of each type of novel food.

MC: Research concerning safety, shelf life, and long-term nutritional and health effects of plant-based meat alternatives is limited. Microbial counts in these products are relatively low due to high temperature and high pressure used in the processing and manufacturing of plant-based meat. However, post-processing contamination is still a threat and pathogens such as Salmonella and Listeria monocytogenes should be considered. Additionally, since these types of products undergo an extrusion process (heat and pressure), endospores may survive, leading to the sporulation of some Bacillus and Clostridium pathogens.

MC: Implementing good HACCP and pathogen environmental monitoring programmes is key in helping to control foodborne microorganisms. The time and temperatures used in the extrusion process are critical control points that should be monitored closely. Finished product testing for pathogens such as Salmonella and L. monocytogenes, and endospores such as Bacillus spp. and Clostridium spp. should be considered. Having a proper pathogen environmental monitoring programme is key in helping to prevent the re-introduction of pathogens. Testing product and non-product contact surfaces for the presence of Salmonella spp. and Listeria spp. not only verifies the effectiveness of the cleaning and sanitation processes, but also determines the presence of foodborne pathogens in the environment.

MC: Bio-Rad offers a range of pathogen and indicator organism testing solutions. The iQ-Check PCR kit range has validated test kits for pathogens like Salmonella spp., Listeria spp., and Listeria monocytogenes that can provide results in less than 24 hours. Additionally, the RAPID Chromogenic media range includes easy-to-use chromogenic agar for pathogens like Bacillus cereus. What is always critical for testing any type of product – not just plant-based meat – is to verify fit-for-purpose for any test method being implemented. Bio-Rad can provide support for this fit-for-purpose verification with its application laboratories located in the US and France.