Toward 6 log10 pulsed electric field inactivation with conductive packaging material

Generally, high grade products such as pulsed electric field (PEF) treated fruit juices are packaged after their preservative treatment. However, PEF treatment after packaging could avoid recontamination of the product and becomes feasible when electric field pulses of sufficient magnitude can be generated inside closed food containments. Microbial inactivation of 2 log10 was proved by using an electrically conductive plastic packaging material, and in this contribution it is shown that inactivation toward pasteurization level is achievable. Therefore, a series of microbial experiments with Lactobacillus plantarum at different energy levels were performed. The obtained microbial data with the plastic material have been compared with inactivation models from literature as well as with reference experiments. All treatments were done at ~2.3 kV/mm, with treatment times between 10¿600 µs, and the thermal load was below 38C. The maximum obtained microbial inactivation with the plastic packaging material was 5.9 log10 with a specific energy of 255 J/mL.