Spray and aerosolised pH-neutral electrochemically activated solution reduces Salmonella Enteritidis and total bacterial load on egg surface

Abstract

The effectiveness of sprayed and aerosolised pH-neutral electrochemically activated solutions (ECAS) containing 150 mg/L of free available chlorine in reducing total bacteria load and artificially inoculated Salmonella enterica serotype Enteritidis 11RX on eggs surfaces was investigated. Treatment groups included untreated control, sodium hypochlorite (positive control), sprayed and aerosolised water and sprayed and aerosolised ECAS. Sprayed ECAS (150 mg/L, 45 s) showed a significant reduction in total bacterial load (2.2 log reduction, p < 0.0001) and S. Enteritidis (5.4 log reduction, p < 0.0001) when compared with the untreated control. Aerosolised ECAS (120 s) was effective in reducing both the total bacterial load (1.4 log reduction, p < 0.01) and S. Enteritidis (4.2 log reduction, p = 0.0022). However, aerosolised ECAS (60 s) only significantly reduced S. Enteritidis counts (2.8 log reduction, p < 0.0008), indicating that a longer time for bacterial reduction during fogging sanitisation is needed. Tests performed with one egg per oscillating tray were more effective in reducing both the total bacterial load and the S. Enteritidis counts than those with three eggs per oscillating tray. Sprayed ECAS (45 s) and aerosolised ECAS (120 s) did not deteriorate the egg cuticle integrity (DEab *), which was evaluated using Cuticle Blue dye solution and colour intensity measurement. Overall, both the reduction in total bacteria counts and S. Enteritidis from the egg surface and retention of cuticle integrity suggest that sprayed and aerosolised ECAS could be used as alternative sanitising approaches to improve the food safety aspect of table eggs.