Survival of foodborne pathogens on stainless steel soiled with different food residues

Abstract

Insufficient and ineffective cleaning practices can cause food residues to remain in kitchen and can facilitate bacterial attachment and persistence by protective films. The present study investigated the survival of five major foodborne pathogens on stainless steel coupons, in the presence of cooked rice, whole eggs, and soymilk. Foodborne pathogens showed different survival rates by desiccation and disinfection depending on food residues. Overall, the pathogens showed stronger survival than the control at 0.13-3.97 log CFU/coupon with 5% residues, and at 0.75-5.29 log CFU/coupon with 50% residues. Staphylococcus aureus was not affected by the food residue with showing the least difference in concentration, while Escherichia coli O157:H7 showed the most significant increase by food residue. The cells with cooked rice were observed using FE-SEM, and demonstrated bacterial binding or embedment. All results suggest that food safety can be practically ensured by food residue types and appropriate cleaning and disinfectants.