Modelling the combined effect of chlorine, benzyl isothiocyanate, exposure time and cut size on the reduction of Salmonella in fresh-cut lettuce during washing process. (April 2020)

• Record Type: Journal Article
• Authors: Cuggino, Sofia Griselda; Bascón-Villegas, Isabel; Rincón, Francisco; Pérez, Maria Alejandra; Posada-Izquierdo, Guiomar; Marugán, Javier; Pablos Carro, Cristina; Pérez-Rodríguez, Fernando
• Is Part Of: Food microbiology. Volume 86(2020)
• Publication Date: 2020-04
• Subjects: Predictive microbiology -- Composite central design -- Vegetable disinfection -- Response surface methodology -- Quantitative microbial risk assessment -- Sodium hypochlorite -- Microbial inactivation; Food Microbiology -- Periodicals; Aliments -- Microbiologie -- Périodiques; Food -- Microbiology; Periodicals; Food -- Microbiology -- Periodicals; Food contamination -- Periodicals; 664.001579
• DOI: 10.1016/j.fm.2019.103346
• Languages: English
• ISSNs: 0740-0020

Abstract

Abstract: This work aimed to study the effect of the combination of Sodium hypochlorite, the most used disinfectant by the vegetable industry, with a natural antimicrobial, benzyl-isothiocyanate (BITC), considering cutting surface and contact time, on the reduction of Salmonella in fresh-cut produce in washing operations under typical industrial conditions. Overall, the combinations of disinfectant and process parameters resulted in a mean reduction of Salmonella of 2.5 log CFU/g. According to statistical analysis, free chlorine and BITC concentrations, contact time and cut size exerted a significant effect on the Salmonella reduction (p ≤ 0.05). The optimum combination of process parameter values yielding the highest Salmonella reduction was a lettuce cut size of 15 cm 2 washed for 110 s in industrial water containing 160 mg/L free chlorine and 40 mg/L BITC. A predictive model was also derived, which, as illustrated, could be applied to optimize industrial disinfection and develop probabilistic Exposure Assessments considering the effect of washing process parameters on the levels of Salmonella contamination in leafy green products. The present study demonstrated the efficacy of chlorine to reduce Salmonella populations in fresh-cut lettuce while highlighting the importance of controlling the washing process parameters, such as, contact time, cut size and concentration of the disinfectant to increase disinfectant efficacy and improve food safety. Highlights: Chlorine reduced Salmonella populations 2.5 log CFU/g on fresh-cut lettuce. Benzyl-isothiocyanate combined with chlorine improved disinfection efficiency. Cutting size and contact time had a significant influence on Salmonella reductions. The optimum was 15 cm 2 cut size and 160 and 40 mg/L free chlorine and BITC for 110 s. An Exposure assessment, using the disinfection model, predicted a 40% reduction.