Published in Food Safety
Inactivation of Listeria monocytogenes on paperboard

Researchers from The Hebrew University of Jerusalem, Israel, have developed a method to inactivate Listeria monocytogenes on paperboard used as a food packaging material; the results were published on Food Control 96, 281-290, 2019.

Light emitting diodes of wavelength 410 nm were used to inactivate Listeria monocytogenes stains on paperboard, an increasingly popular food packaging material. The integrity of the cell membranes was examined using differential fluorescent staining. Scanning electron microscopy (SEM) was used to obtain a deeper understanding of L. monocytogenes stain formation on paperboard and the damage caused to the cells by the LEDs. While the planktonic L. monocytogenes population could be completely inactivated following a brief lag phase that lasted about 20 min, the illumination of the sessile population left some persisters despite immediate commencement of the inactivation. Planktonic populations of inocula sized 3, 5 and 7 log CFU/mL were reduced below the detection limit in 54, 80 and 84 min respectively, whereas it took 120 and 390 min to reach constancy in the sessile populations of inocula sized 5 and 7 log CFU/cm2. The number of membrane-damaged cells was seen to increase with the illumination time. SEM images provided evidence of the protection conferred by the stain on the underlying cells. This study demonstrates that blue LEDs have the potential to reduce the risk of L. monocytogenes contamination from paperboard cartons under refrigeration.

Leave a comment

Make sure you enter all the required information, indicated by an asterisk (*). HTML code is not allowed.

Image
Copyright © 1998-2020 Chiriotti Editori srl Tutti i diritti riservati
Viale Rimembranza, 60 - 10064 Pinerolo - To - Italy - P.IVA e C.F. 01070350010 - Tel. +39 0121.393127 - Fax +39 0121.794480 - email info@foodexecutive.it | Disclaimer