Inactivation of Salmonella in liquid egg albumen by antimicrobial bottle coatings infused with allyl isothiocyanate, nisin and zinc oxide nanoparticles

Aims: To develop an antimicrobial bottle coating effective at inhibiting the growth of Salmonella in liquid egg albumen (egg white) and reduce the risk of human Salmonellosis. Methods and Results: Four-ounce glass jars were coated with a mixture of polylactic acid (PLA) polymer and antimicrobial compounds containing 100-500 mu l allyl isothiocyanate (AIT), 250 mg nisin, 250 mg zinc oxide nanoparticles per jar or their combinations. The coated jars contained 100 ml of liquid egg white (LEW) inoculated with a three-strain Salmonella enterica ssp. enterica cocktail at populations of 103 or 107 CFU ml-1 and stored at 10 degrees C for 28 days. The PLA coating with 500 mu l AIT completely inactivated 3 and 7 log CFU ml-1 of Salmonella after 7 and 21 days of storage, respectively. The PLA coating with 200 mu l AIT in combination with 250 mg nisin reduced Salmonella populations to an undetectable level (< 10 CFU ml-1) after 21 days of storage. Conclusions: PLA coatings containing AIT alone or in combination with nisin effectively inactivated salmonellae in LEW. Significance and Impact of the Study: This study demonstrated the commercial potential of applying the antimicrobial bottle coating method to liquid eggs and possibly other fluid food products.