Pulsed Electric Fields as a Cutting-Edge Solution to Ensure the Safety of Pineapple Juice: Targeting Escherichia coli O157:H7 and Listeria monocytogenes 5672

This study evaluates the effectiveness of pulsed electric field (PEF) technology for pasteurizing pineapple juice to inactivate Escherichia coli O157:H7 and Listeria monocytogenes 5672. Pineapple juice was treated with PEF pulses of 5 μs at electric field intensities of 15, 20, and 25 kV/cm, with frequencies ranging from 8 to 44 Hz. Treatment durations ranged from 12 to 197 s, corresponding to energy levels between 18 and 192 kJ/kg, while exit temperatures were controlled between 40 and 70 °C. Results showed that higher exit temperatures and electric field strengths significantly enhanced the inactivation of E. coli O157:H7, with the most effective treatment being at 70 °C and 25 kV/cm, achieving ≥3-log reductions. For L. monocytogenes 5672, reductions of 4–5 log cycles were observed under most conditions, except at 15 kV/cm, where a 2-log reduction was noted. After treatment, all samples were incubated for 72 h under refrigeration; E. coli O157:H7 showed an additional lethal effect during storage. This leads to reductions exceeding 5 logs for those juices treated at 20 and 25 kV/cm, while L. monocytogenes 5672 showed less significant changes. These findings highlight the potential of PEF technology for enhancing food safety in juice preservation.