A challenge study of foodborne pathogens in clean-label acidified dressings: Cold-fill kinetic modeling study

• Kinetic parameters were estimated for the inactivation of L. monocytogenes, E. coli O157:H7, and S. Typhimurium in acidified, cold-filled, clean-label products • Hold time required for 5-log reduction of pathogenic microorganisms was obtained, using Log-linear and Weibull models • The Weibull model was a better fit across different products and different bacteria, showing low errors and narrow confidence intervals • Findings from this study can be used for the development of safer product release criteria and more efficient supply chains for clean-label products Ensuring the safety of food products is paramount in the food industry, with particular attention given to those products characterized by acidification to low pH levels. Historically, acidified food products have been regarded as safe due to the unfavorable conditions they create for the survival of foodborne pathogens and public health significance organisms. However, the growing consumer demand for clean-label foods has led to the development of novel formulations without traditional additives that safeguard against microbial growth. This study addresses the gap in food safety knowledge of acidified clean-label products. The study aimed to determine the requisite time for achieving a 5-log reduction in pathogen counts in cold-filled salad dressings at 25°C and pH 3.3. The inactivation kinetics of three common foodborne pathogens, namely L. monocytogenes, E. coli O157:H7, and S. Typhimurium were investigated in three different products. The Log-linear and Weibull models were used as inactivation models to estimate the kinetic parameters. Metrics such as Root Mean Square Errors (RMSE) and Sum of Squares (SS) were used to compare the performance of the two models. For all three bacteria, the Weibull model provided a superior fit. The survival study revealed differential resistance among the pathogens, with E. coli O157:H7 exhibiting greater resilience for all products. For avocado lime dressing, as per the Weibull model, the hold time required to achieve 5-log reduction for E. coli O157:H7, L. monocytogenes , and S. Typhimurium was 29.42, 23.18, and 26.85 hours respectively. For the creamy garlic herb dressing, the duration to achieve the equivalent log reduction was shorter; 18.48, 9.67, and 17.40 hours for E. coli O157:H7, L. monocytogenes , and S. Typhimurium respectively. In the raspberry champagne matrix, the required hold time was estimated to be 17.98 hours for E. coli O157:H7, 6.84 hours for L. monocytogenes , and 15.30 hours for S. Typhimurium. The outcomes of this study can provide valuable insights for the manufacturers of clean-label, acidified products for the development of safer food products and enhanced supply chain management.