Processing of leafy vegetables matters: Damage and microbial community structure from field to bag

Abstract

Leafy vegetables undergo abiotic and biotic stresses, and a series of processing steps that cause mechanical injury. Breaching the epidermis alters phyllosphere structural and nutrient conditions, resulting in successional shifts in leaf microbiota and entry of human pathogens. This study examined damage during processing of baby leaves (Swiss chard, spinach) and concomitant microbial successional events. Machine-harvesting, washing, and packaging caused major phyllosphere perturbations, with increasing levels of leaf damage. Older leaves showed most damage, but plant species was influential. Diversity estimates of bacterial and fungal communities revealed shifts in microbiota post-harvest, particularly after the washing step. Relative abundance of Pseudomonadaceae and Enterobacteriaceae increased from field to bag. Bacterial species specific to different harvesting and processing steps replaced core microbiota species. While processing is unavoidable, procedures that mitigate leaf damage can enhance shelf-life and food safety.

Keywords

damage; Escherichia coli O157:H7; microbiota; post-harvest; spinach; swiss chard

Published in

Food Control
2021, Volume: 125, article number: 107894

SLU Authors

• Lindblom, Tobias

  • Department of Crop Production Ecology, Swedish University of Agricultural Sciences
    

• Windstam, Sofia

  • Department of Biosystems and Technology, Swedish University of Agricultural Sciences
    
  • State University of New York at Oswego (SUNY Oswego)

• Bengtsson, Marie

  • Department of Plant Protection Biology, Swedish University of Agricultural Sciences
    

• Rosberg, Anna Karin

  • Department of Biosystems and Technology, Swedish University of Agricultural Sciences
    

• Mogren, Lars

  • Department of Biosystems and Technology, Swedish University of Agricultural Sciences
    

• Alsanius, Beatrix

  • Department of Biosystems and Technology, Swedish University of Agricultural Sciences
    

• Mulaosmanovic, Emina

  • Department of Biosystems and Technology, Swedish University of Agricultural Sciences
    

Sustainable Development Goals

SDG2 Zero hunger


UKÄ Subject classification

Food Science
Microbiology


Publication identifier

DOI: https://doi.org/10.1016/j.foodcont.2021.107894

Permanent link to this page (URI)

https://res.slu.se/id/publ/110564