Effects of chlorine and peroxyacetic acid wash treatments on growth kinetics of Salmonella in fresh-cut lettuce

• Autores: Cuggino, Sofia; Posada Izquierdo, Guiomar; Bascón Villegas, Isabel; Theumer, Martín Gustavo; Pérez-Rodríguez, Fernando
• Año de publicación: 2023
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: BACTERIAL ATTACHMENT; BĚLEHRÁDEK MODEL; CROSS CONTAMINATION; GROWTH RATE; INTERNALIZATION; LETTUCE DISINFECTION; MICROBIAL RISK ASSESSMENT; MODIFIED ATMOSPHERE PACKAGING; PREDICTIVE MODELS
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

Fresh-cut produces are often consumed uncooked, thus proper sanitation is essential for preventing cross contamination. The reduction and subsequent growth of Salmonella enterica sv Thompson were studied in pre-cut iceberg lettuce washed with simulated wash water (SWW), sodium hypochlorite (SH, free chlorine 25 mg/L), and peroxyacetic acid (PAA, 80 mg/L) and stored for 9 days under modified atmosphere at 9, 13, and 18 °C. Differences in reduction between SH and PAA were non-existent. Overall, visual quality, dehydration, leaf edge and superficial browning and aroma during storage at 9 °C were similar among treatments, but negative effects increased with temperature. These results demonstrated that PAA can be used as an effective alternative to chlorine for the disinfection of Salmonella spp. in fresh-cut lettuce. The growth of Salmonella enterica sv Thompson was successfully described with the Baranyi and Roberts growth model in the studied storage temperature range, and after treatment with SWW, chlorine, and PAA. Subsequently, predictive secondary models were used to describe the relationship between growth rates and temperature based on the models’ family described by Bělehrádek. Interestingly, the exposure to disinfectants biased growth kinetics of Salmonella during storage. Below 12 °C, growth rates in lettuce treated with disinfectant (0.010–0.011 log CFU/h at 9 °C) were lower than those in lettuce washed with water (0.016 log CFU/h at 9 °C); whereas at higher temperatures, the effect was the opposite. Thus, in this case, the growth rate values registered at 18 °C for lettuce treated with disinfectant were 0.048–0.054 log CFU/h compared to a value of 0.038 log CFU/h for lettuce treated with only water. The data and models developed in this study will be crucial to describing the wash-related dynamics of Salmonella in a risk assessment framework applied to fresh-cut produce, providing more complete and accurate risk estimates.
Fil: Cuggino, Sofia. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias. Departamento de Fundamentación Biológica; Argentina
Fil: Posada Izquierdo, Guiomar. Universidad de Córdoba; España
Fil: Bascón Villegas, Isabel. Universidad de Córdoba; España
Fil: Theumer, Martín Gustavo. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; Argentina
Fil: Pérez-Rodríguez, Fernando. Universidad de Córdoba; España