Assessment of the use of ozone for cleaning fatty soils in the food industry

The development of safe, efficient and environmentally compatible detergent formulas is an important issue for the food industry in order to ensure adequate levels of quality and safety, while saving energy and time. In this work we have evaluated the capacity of ozone, a strong oxidant declared as a GRAS additive, to remove greasy stains from hard surfaces. Firstly we studied the effect of ozone on a model alimentary fat, pork lard, and several detergent components: three surfactants, and a lipase. Finally washing experiments where conducted in a continuous flow device which simulates an industrial clean-in-place system, in order to establish a suitable strategy for cleaning processes involving ozone. Ozonation of pork lard in aqueous medium led to the formation of surface active molecules, presumably fatty acids, which resulted in a slight but significant improvement of washing performance compared to that of water. The three surfactants tested retained all or part of their surface activity for short ozonation times, and the inclusion of ozone did not affect their washing efficiency significantly, even under alkaline conditions. Conversely enzyme residues were readily deactivated by rinsing with ozonated water, which helps to prevent food contamination.