Effect of Antimicrobial Washes, Essential Oil Vapor Phase, and Antimicrobial Pullulan Coating in Reducing Escherichia coli O157:H7 and Salmonella Typhimurium on Strawberries

The aim of this study was to evaluate three different antimicrobial strategies—washes, essential oil vapor phases, and coatings—against Escherichia coli O157:H7 and Salmonella Typhimurium to improve the safety of strawberries. Results indicated that 0.5% acetic acid and acidified 0.1% sodium chlorite were effective in reducing the population of E. coli O157:H7 (1.6 and 2.6 log CFU/g) and Salmonella Typhimurium (2 and 2.8 log CFU/g), respectively. Thyme essential oil vapor at 500 µL/Lair showed greater inhibition against E. coli O157:H7 and Salmonella Typhimurium on strawberry (2 and 3 log CFU/g, respectively) than oregano oil (1.5 and 2.5 log CFU/g, respectively; P < 0.05). During challenge studies, the coatings containing grape seed nanoparticles and pomegranate peel nanoparticles were demonstrated to effectively inhibit (P < 0.05) these pathogens compared with the control coatings. Overall, a greater antimicrobial activity (>4 log CFU/g) was observed when the different systems were combined, demonstrating the possibility to use these strategies to improve the quality and safety of strawberries.