Spray and Aerosolised pH-Neutral Electrochemically Activated Solution Reduces Salmonella Enteritidis and Total Bacterial Load on Egg Surface

Sangay Tenzin,Sergio Ferro,Darren J Trott,Permal Deo,Samiullah Khan

doi:10.3390/app11020732

Sangay Tenzin, Sergio Ferro + Show 3 more

Open Access

https://doi.org/10.3390/app11020732

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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 (ΔEab*), 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.

Highlights

Pathogenic serotypes of Salmonella are a major cause of foodborne diseases worldwide.The annual proportion of food origin salmonellosis in Australia is about 40,000 out of an estimated total of about 4.1 million foodborne gastroenteritis cases [1]
We explored the potential of pH-neutral electrochemically activated solutions (ECAS) (150 mg/L of free available chlorine (FAC)) as spray and aerosol fog for the sanitisation of unwashed, visibly clean eggs, assessing the reduction in total bacterial counts and Salmonella Enteritidis, and its effects on the cuticle layer
colony forming unit (CFU)/egg) showed no significant reduction (p = 0.3662) in total bacterial load when compared with the untreated control (2.2 ± 0.2 log10 CFU/egg; Table 1)

Summary

Introduction

Pathogenic serotypes of Salmonella are a major cause of foodborne diseases worldwide. The annual proportion of food origin salmonellosis in Australia is about 40,000 out of an estimated total of about 4.1 million foodborne gastroenteritis cases [1]. Salmonella- associated foodborne illnesses have risen during the past 20 years and the rate of salmonellosis in Australia is much higher compared to economically similar countries [2]. It has been estimated that foodborne illnesses due to Salmonella spp. have caused up to 35% of hospitalisations and 28% of mortalities [1], and the hospitalisation and death cases were higher in comparison to other foodborne illnesses [1]. Among the salmonellosis cases of foodborne origin, raw eggs and egg-based products have the highest frequency [3,4,5].

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