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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Environmental Microbial & Food Safety Laboratory » Research » Publications at this Location » Publication #404675
Research Project: Intervention Strategies to Mitigate the Food Safety Risks Associated with the Fresh Produce Supply Chain

Location: Environmental Microbial & Food Safety Laboratory

Title: Influence of contamination source and cultivation matrix on survival of Escherichia coli O157:H7 and Salmonella enterica on daikon microgreens

Author
item CHEN, CHI-HUNG - Orise Fellow
item YIN, HSIN-BAI - Food And Drug Administration(FDA)
item Patel, Jitu

Submitted to: LWT - Food Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/31/2023
Publication Date: 8/4/2023
Citation: Chen, C., Yin, H., Patel, J.R. 2023. Influence of contamination source and cultivation matrix on survival of Escherichia coli O157:H7 and Salmonella enterica on daikon microgreens. LWT - Food Science and Technology. 185. Article e115165. https://doi.org/10.1016/j.lwt.2023.115165.
DOI: https://doi.org/10.1016/j.lwt.2023.115165

Interpretive Summary: Consumption of microgreen has increased in recent years due to their health benefits, particularly bioavailability of micronutrients. Growth of microgreen in a humid environment and lack of post-harvest interventions may favor contamination of bacterial pathogens. Further, microgreens are consumed raw which could cause foodborne illnesses if previously contaminated with pathogens. We evaluated sources of contamination (seed, water) and cultivation media (Composted manure with soil-CG, Vermiculite perlite-VP, and Biostrate pads-BP) on persistence of bacterial pathogens on daikon microgreen. Salmonella and Escherichia coli O157:H7 were found on microgreens harvested at 14 days when seeds or irrigation water was contaminated. Recovery of these bacterial pathogens were significantly lower on CG-grown microgreen. Lower yield was observed with Daikon microgreen grown on BP media. Results help microgreen growers in selecting cultivation media for higher yield and lower pathogen contamination.

Technical Abstract: Consumption of microgreens has increased lately due to availability of bioactive compounds. However, they may present food safety risk similar to fresh produce and sprouts. Effect of cultivation matrixes and contamination routes on the survival of Escherichia coli O157:H7 (EHEC) and Salmonella on daikon microgreen was investigated. Daikon microgreens contaminated with EHEC or Salmonella via seeds or irrigation water were cultivated on Composted cattle manure with soil (CG), Vermiculite perlite (VP), and Biostrate pads (BP) for 14 days. Surviving pathogens on microgreens and matrixes were determined by plating on selective agars. CG grown microgreens showed significantly lower Salmonella populations compared to that recovered from BP-grown microgreens on day 14 when contaminated via seed. Similar results were obtained through irrigation water contamination, in which the recovery of Salmonella and EHEC from CG-grown microgreens was significantly lower than BP grown microgreens on day 14. In addition, significantly higher populations of EHEC and Salmonella were recovered from BP matrix compared to these pathogens from CG and VP on days 0, 7 and 14. Results of this study suggest that both contamination routes pose potential food safety risk as pathogens could survive on microgreens for 14 days. Consumption of microgreens has increased lately due to availability of bioactive compounds. However, they may present food safety risk similar to fresh produce and sprouts. Effect of cultivation matrixes and contamination routes on the survival of Escherichia coli O157:H7 (EHEC) and Salmonella on daikon microgreen was investigated. Daikon microgreens contaminated with EHEC or Salmonella via seeds or irrigation water were cultivated on Composted cattle manure with soil (CG), Vermiculite perlite (VP), and Biostrate pads (BP) for 14 days. Surviving pathogens on microgreens and matrixes were determined by plating on selective agars. CG grown microgreens showed significantly lower Salmonella populations compared to that recovered from BP-grown microgreens on day 14 when contaminated via seed. Similar results were obtained through irrigation water contamination, in which the recovery of Salmonella and EHEC from CG-grown microgreens was significantly lower than BP grown microgreens on day 14. In addition, significantly higher populations of EHEC and Salmonella were recovered from BP matrix compared to these pathogens from CG and VP on days 0, 7 and 14. Results of this study suggest that both contamination routes pose potential food safety risk as pathogens could survive on microgreens for 14 days.