Salmonella survival during soft-cooked eggs processing by steam oven

Abstract

Worldwide, despite concerns about the possibility of Salmonella presence in eggs and the recommendations of regulatory agencies, soft-cooked eggs are served. Studies indicate that eggs cooked at low temperature for long times are able to inactivate Salmonella at safe levels. There are two main low cooking methods used in food services, thermocirculator (tested in a previous study) and steam oven, not yet validated. This study was undertaken to analyze the survival of Salmonella during soft-cooked eggs processing by steam oven. Five strains of Salmonella were inoculated in egg yolks and incubated at 37 °C, for 18 h, reaching 8.1 ± 0.1 log10 CFU/g. Contaminated eggs were processed at 62 °C for 52 min in asteam oven and samples were collected for the purpose of investigating Salmonella survival. Results indicated that the egg's center temperature reached 58.7 ± 0.4 °C after 17 min and no Salmonella was detected. After 52 min of cooking, yolk remained liquid. The results of this study demonstrated that soft-cooked eggs processing by steam oven showed similar results to the processing by thermocirculator and can also be used by chefs and food processors in order to validate another way of serving soft-cooked eggs safely.