Biological risk assessment of microbial hazards in food waste valorisation streams for safe circular food systems

Abstract

The rapid growth of food waste valorization within the framework of circular food systems has opened up new possibilities for the sustainable recovery of resources, but also poses unclear and less explored biological threats. Food waste streams provide dynamic habitats for a wide range of microbial communities that comprise foodborne pathogens, spoilage organisms, toxin producing fungi, viruses, parasites, and anti microbial resistant (AMR) bacteria. Their survival, growth, and ecology during collection, storage, and bioprocessing pose a significant challenge to food safety and general health, particularly when valorised products are reintroduced into the food or feed chain. The review presents the existing information on microbial hazards during waste-to-wealth operation and sheds light on factors that facilitate the amplification of risks, i.e., biofilm formation, virulence under stress, and horizontal gene transfer. New developments in multiomics profiling, metagenomics, predictive microbiology, artificial intelligence and computational modelling are discussed in relation to their potential to improve biological risk assessment in valorization systems. Risk mitigation strategies such as biocontrolling strategies that are based on fermentation, artificial microbial consortia, CRISPR-based biosensing, and hurdle based inactivation technologies have been discussed. The review describes regulatory gaps and suggests a safety-by-design model to make sure that innovations based on the use of waste are sustainable and safe.