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Antimicrobial Peptides Produced by Selective Pressure Incorporation of Non-canonical Amino Acids
Published on: May 4, 2018
Photoirradiated caffeic acid as an antimicrobial treatment for fresh produce
Andrea R Gilbert1, Solmaz Alborzi1, Luis J Bastarrachea2
1Department of Nutrition and Food Science, University of Maryland, College Park, 112 Skinner Building 20742, USA.
Abstract:
The antimicrobial efficacy of 400 nm photoirradiated caffeic acid (CA, 5 mM) was evaluated against Escherichia coli O157:H7 and Listeria innocua. A stronger antimicrobial effect was observed on E. coli than on L. innocua where the combined treatment resulted in 4 and 1 log(CFU/mL) reductions, respectively. The treatment's effects on cellular metabolism (resazurin assay), uptake of CA (fluorescence technique) and membrane damage (propidium iodide assay) were studied in both species. CA uptake increased in both species, but membrane damage was only observed in E. coli O157:H7. The treatment had minimal impact on metabolic activity in both species. The treatment applied to the surface of spinach leaves was found to be effective against E. coli O157:H7. The novel treatment proposed in this study has the potential to improve the microbial food safety of fresh produce.
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