FARM-TO-FORK MICROBIAL RISKS IN HYDROPONIC AND INDOOR MICROGREENS: A SCOPING REVIEW OF CONTAMINATION PATHWAYS, PREVENTIVE CONTROLS, AND PRIORITIES

Abstract

Microgreens are often eaten raw and are now more often grown using hydroponic, vertical and other controlled environment technologies. While enclosures can decrease exposure to splashed soil, wildlife, and rain, they still do not eliminate microbial contamination risks from seeds, water, nutrient solutions, substrates, tools, personnel, packaging, and storage. Mapping the existing evidence on microbial contamination risks, indicators, foodborne pathogens, and any necessary controls and verification on the farm to fork continuum in India is the objective of this study. A scoping review, done and reported as per the PRISMA-ScR guidelines, was the chosen method. A reconstructed search log included Scopus, Web of Science, PubMed, ScienceDirect, Google Scholar, and citation analysis. Out of 1,028 research articles found, 742 remained after de-duplication, 130 were reviewed in full, and 50 research articles were included in the review. Evidence was organized by source, organism or indicator, stage of food production, control, verification, and limit. Irrigation water, nutrient water, and seed and soilless media were the most cited contamination entry routes. Total plate count and coliforms were the most cited indicators of contamination along the food production continuum. It is recommended the multi- hurdle model of contamination control be implemented along the food production continuum in India. Of all the recommendations made to improve food safety, many were focused on postharvest practices, and most of the recommended safety interventions lacked microbial baselines. Indoor growing of food should be considered controllable. Risk reduction relies on verified farm-to-fork controls and evidence specific to the system rather than production labels and end-product washing.