When nanoemulsified, d-limonene reduces Listeria monocytogenes heat resistance about one hundred times

© 2015 The Authors. The application of oily antimicrobials in form of nanoemulsion has been proved to solve the problem of their immiscibility in aqueous media, still preventing microbial growth and even improving the antimicrobial effect observed when applied directly. At present, only a few documented studies have evaluated the combined effect of nanoemulsions with other factors of stress for the microorganism. The present research shows very promising results on the combination of nanoemulsified d-limonene with thermal treatments on the inactivation of Listeria monocytogenes. The thermal resistance of L. monocytogenes was reduced two to five times when 0.5 mM d-limonene was added directly to the heating medium. However, when the same concentration of d-limonene was present in the heating medium in form of nanoemulsion, the heat resistance was reduced by one hundred times at all heating temperatures tested. The addition of nanoemulsified antimicrobials would allow to reduce greatly the intensity of the thermal treatments currently applied in the food processing industry.