ANTIBACTERIAL PROPERTIES OF A NON-THERMAL, OPENAIR, ATMOSPHERIC PLASMA JET IN SURFACE DECONTAMINATION OF EGGS IN SHELL

Abstract

In the European Union, eggs may not be washed or cleaned. So, in order to reduce food safety risks, several techniques for eggs in shell decontamination have been developed. The current study was undertaken to determine the potential of the Non-thermal, Atmospheric, Openair® Plasma Jet for surface decontamination of eggs in shell. In the experiment Polyethylene Theraphtalate plates and the eggshells of table eggs were exposed to single or multiple treatments with a Non-thermal, Atmospheric, Openair® Plasma Jet. This resulted in up to > 3 log reduction of Staphylococcus aureus (S. aureus) (NCTC 8325) on Polyethylene Theraphtalate and 1.8–2.5 log reduction of a common number of native aerobic mesophylic bacteria and S. aureus (NCTC 8325) on eggshells in a treatment time of 10-60 seconds. Ionising gas of the plasma jet was obviously not harmful to eggshell cuticle, since no significant alterations to plasma-treated eggs were found, or to physico-chemical properties of the contents of plasma-treated eggs, such as: air cell height, pH, the whole weight of eggs, or height of the thickness of egg white, which did not significantly differ from the untreated eggs during 54 days of aging. The results of the experiment indicate that the treatment of eggshells with the plasma jet has the potential for egg in shell decontamination with no side effects on egg quality, which is important as far as food safety and quality characteristics that are acceptable to consumers.