Effect of <scp>UVC‐LED</scp> and ultrasound alone and combined on heat‐resistant <i>Escherichia coli</i> isolated from pasteurised milk
Maxsueli Aparecida Moura Machado, Vinícius Silva Castro, Maria Lúcia Guerra Monteiro, Yago Alves de Aguiar Bernardo, Eduardo Eustáquio de Souza Figueiredo, Carlos Adam Conte‐Júnior
Abstract
We aimed at characterising the nonthermal technologies resistance profile of two Escherichia coli strains isolated from pasteurised milk and described as moderate‐to‐high heat resistance (MHR) (60°C/6 min) harbouring or not a transmissible locus of stress tolerance (tLST). The characterisation was carried out applying optimised conditions of ultraviolet‐C light‐emitting diodes (UVC‐LED) (4950 mJ/cm 2 ), ultrasound (US) (299 W) and their combination (UVC‐LED + US). Both strains were more sensitive to UVC‐LED (4.5–1.5 log cfu/mL) than to US (<1 log cfu/mL) or UVC‐LED + US (4.5–1.5 log cfu/mL), which did not exhibit synergism. Thus, UVC‐LED is a promising technology to eliminate E. coli harbouring tLST.