Research note: Penetration of ozone gas across the shell of hen eggs

Increasing evidence indicates that ozone gas is effective against Salmonella on and within shell eggs. However, information on the penetration of ozone across egg shell is limited. In this study, whole hen egg shells, filled with indigotrisulfonate solution (OD600 similar to 1), were exposed to ozone gas (12-14% wt/wt O-3 in O-2) at 1.5 liters/min and atmospheric pressure for similar to 40 min with appropriate controls. Ozone penetrated the shells over time (r(2) = 0.9974) causing indigo decoloration and increasing its transmittance from 16 to 28% after gas exposure for 40 min. This study confirms ozone penetration through egg shell using a simple qualitative technique.