Pulsed Electric Fields in Food Processing
Pulsed Electric Fields in Food Processing
The food industry faces the challenge of producing safe, nutritious and high-quality foods while reducing energy and water consumption, improving the use of raw materials and minimizing waste. Pulsed electric field (PEF) technology can contribute to addressing these challenges through cell electroporation, enabling faster, more selective and less intensive processing operations while improving the efficiency of food production.
The preservation of heat-sensitive liquid foods such as fruit and vegetable juices was one of the earliest applications of PEF in food processing. Microbial inactivation can be achieved with a lower thermal load than that required by conventional heat treatments, helping to retain fresh flavour, colour and heat-sensitive nutrients.
However, the potential of PEF extends far beyond food preservation. By inducing controlled electroporation, PEF enhances mass transfer, facilitates the release of intracellular compounds and modifies the physical properties of biological tissues. As a result, it can improve the efficiency of a wide range of food manufacturing operations, including pressing, extraction, drying and other processes involving plant, animal or microbial materials. Importantly, the greatest savings in energy, water and other processing inputs are often achieved not during the PEF treatment itself, but in the downstream operations.
One of the best-established industrial applications is potato processing for frozen French fries and potato chips. In this application, PEF pretreatment is applied before cutting to soften and homogenize the tissue structure, improving cutting performance, reducing mechanical damage and increasing product yield. The improved tissue properties also shorten frying and drying times, reduce oil uptake and contribute to a more uniform product colour and quality.
The technology is also gaining increasing relevance in sustainable biorefining, where the objective is to maximise the value obtained from biomass by recovering multiple products through integrated processing schemes. By inducing controlled electroporation rather than complete cell disruption, PEF enables selective extraction of intracellular compounds while preserving the structure of the remaining biomass for subsequent processing steps. This makes it particularly suitable for biorefinery concepts based on the sequential recovery of proteins, pigments, polyphenols, sugars, oils and other valuable compounds from crops, algae, yeasts and agri-food by-products. These characteristics make PEF an enabling technology for the design of more efficient, selective and sustainable biorefinery processes, supporting the production of high-value food ingredients and other biobased products.
The difficulty of developing reliable pulse generators and treatment systems capable of handling the high throughputs required by the food industry limited PEF commercial implementation in the past. These engineering challenges have now been overcome in several industrial applications. Continuous industrial equipment capable of processing several tonnes of product per hour has been available for a number of years, and PEF is already an industry-proven technology, particularly in potato and vegetable processing.
PEF should therefore be regarded not simply as an isolated processing step, but as a versatile platform technology for optimizing food production chains. Its greatest potential lies in its integration with existing operations to improve product quality, process performance and the sustainable use of resources across the entire value chain.
— Contributed by Javier Raso