Impact assessment of carvacrol and citral effect on Escherichia coli K12 and Listeria innocua growth

Abstract

The effect of different concentrations of carvacrol [0.1–0.25 μL/mL] and citral [0.25–1.5 μL/mL], at different storage temperatures [8–37 °C] was evaluated against Escherichia coli O157:H7 and Listeria monocytogenes surrogates. Results were integrated into a stochastic model to perform probabilistic predictions of the final load. The study takes into account the variability in growth conditions by means of maximum growth rate (μmax) and lag time duration (λ) kinetic parameters, using the Monte Carlo simulation. Carvacrol showed a greater effectiveness against both bacteria than citral. A sensitivity analysis was carried out revealing that, at low temperatures [8–15 °C], carvacrol contributed to delaying the growth of the studied microorganisms. These results are important for food managers and industrial processors because they reveal the probability of being below a microbial threshold limit in presence of carvacrol and citral, even if a cold chain failure occurs.