Increasingly health-conscious consumers are changing their buying habits. With convenience and nutritional value of paramount importance, products such as bagged lettuce and salads have become increasingly popular in the last 10 years as "healthy fast food" (Koukkidis & Freestone, 2018;Rekhy & McConchie, 2014).The pH of lettuce (5.5-6.0) paired with its high water activity (a w ) value provides optimal conditions for microbial growth (Tirpanalan et al., 2011). This is made worse in cut/shredded lettuce as the surface area is vastly increased making it a highly perishable food which is often implicated in outbreaks of foodborne illness (Qadri