TOWARD 6 log₁₀ PULSED ELECTRIC FIELD INACTIVATION WITH CONDUCTIVE PLASTIC PACKAGING MATERIAL

Abstract

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 ms, 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. PRACTICAL APPLICATIONSIn order to further minimize the risk of contaminating microorganisms, e.g., introduced during the packaging process, this new technology of pulsed electric field (PEF) treatment after packaging can be beneficial in reducing food safety incidents. This technique also makes hygienic packaging machines superfluous, which will reduce operational and investment costs. By proving that PEF inactivation through a plastic packaging material is possible, the first step toward PEF treatment after packaging has been taken. Important next steps toward industrial realization are extensive research on food grade conductive packaging films, PEF in-pack processing methodologies and microbial investigation of different microorganisms.

Review of Green Food Processing techniques. Preservation, transformation, and extraction

“…Generally, PEF treated liquid food is packaged after their preservative treatment. A batch treatment mode, in conductive plastic material, could also be achieved with comparable levels of inactivation (Roodenburg et al, 2013).…”

Eco-friendly preparation of electrically conductive chitosan - reduced graphene oxide flexible bionanocomposites for food packaging and biological applications

“…Electrically conductive biomaterials are promising for applications at the interface between biology and electronics, being employed in biomedical scaffolds, sensors and actuators, as well as electrically conductive food packaging [1][2][3][4]. Electrically conductive polymers can be used to provide the necessary electrical conductivity, but their cytotoxicity and the lack of biocompatibility and biodegradability prevents their use for food and biological applications.…”

Graphene Derivatives in Biopolymer-Based Composites for Food Packaging Applications

“…The same authors also studied the effectiveness of PEF in-pack, using this composite material as a food packaging pouch. The results showed a bacterial inactivation of 5.9 log 10 , which reaches the pasteurization level [ 217 ].…”

“…Food is packaged into an electrically conductive food packaging prior to PEF Table 2 . Adapted from reference [ 217 ] Copyright Wiley-VCH Verlag GmbH & Co, KGaA, Weinheim, 2011.…”