Afterglow corona discharge air plasma (ACDAP) for microbial decontamination of shell eggs: Effect on physicochemical properties

Abstract

Non-chemical disinfection methods are gaining popularity in egg sanitation. In this study, afterglow corona discharge air plasma (ACDAP) was used for microbial decontamination of shell eggs. ACDAP was generated at an output voltage level of 20 kV DC and at a frequency of 58 kHz. Microbial contaminants including aerobic bacteria molds and yeasts and other pathogenic bacteria, namely Staphylococcus aureus were detected on shell surface. Upon the plasma treatment for 12 h, 1.4 log (96%)-1.7 log (98%) reductions of the detected microorganisms were observed. The microbial inactivation pattern fitted well to Singh-Heldman model or pseudo-first-order kinetics. No statistically significant (p>0.05) changes in physicochemical (weight, Yolk index, Haugh units, pH) and sensory characteristics (appearance, aroma, flavor, texture) of eggs were observed due to ACDAP treatment. In addition, improved (p<0.05) storage quality of eggs was observed upon the plasma treatment. The results of this study demonstrate that ACDAP can reduce the overall microbial load including pathogenic bacteria on eggshell surface. The plasma treatment can also help maintain storage quality of eggs for 3 weeks at 25 degrees C without compromising their physicochemical and sensory properties.