Pulsed electric fields (PEF) allow potatoes and other vegetables or fruits to be processed efficiently while increasing the yield, freshness and taste. Elea Technology GmbH brought the process to market maturity together with the German Institute of Food Technologies (DIL) ten years ago. Last November, a two-day event at the company’s headquarters in Quakenbrück demonstrated what technology can meanwhile achieve.
High-voltage pulses for attractive products
On 16 and 17 November 2022, Elea Technology GmbH held its “PEF Advantage Day” at the production site in Quakenbrück. Visitors and partners from all over the world were welcomed to inform themselves about the potential of pulsed electric fields and their advantages for the food and beverage industry. The introduction to the extensive program was provided by expert presentations by Elea Managing Director Prof. Dr. Stefan Töpfl and Dr. Claudia Siemer, Research & Development Manager at Elea. For both, the technology is characterised by its positive effect on the structure of fruit and vegetables.
The PEF principle: For the treatment, the raw materials are exposed to short high-voltage pulses. The electric field causes the pores to open and water can escape. What results is gentle cell disruption and ultimately increased product quality. Treated raw commodities are easier to cut and show less breakage.
Influence during drying
The process is used in the food industry, for example, for the pre-treatment of potatoes in industrial french fry production. The application makes it possible to reduce the frying time and temperature and to reduce unwanted quality losses. Other areas of application are drying potato products, vegetable snacks and crisps as well as treating fruit juices and smoothies. During the two-day event, concrete case studies were discussed in two guest presentations. Marianna Giancaterino spoke about the effects of pulsed electric fields on freeze-drying and removing bitterness from cherry pits. “PEF enables gentle processing without any loss of quality and with lower water and energy consumption,” says the research associate at the Vienna University of Natural Resources and Applied Life Sciences (BOKU).
Artur Wiktor, professor at Warsaw University of Life Sciences, then explained the influence of the electric field on product properties during drying. “The advantage of the process is that it can be combined with all conventional drying methods, be it hot air, freeze, vacuum, microwave or infrared drying,” the scientist pointed out. With air-dried mangoes, he was able to observe a 50 % decrease in the drying time, similar to carrots.
The Elea experts demonstrated the effects on drying using strawberries and carrots. It was shown how PEF can reduce freezing and drying times, thereby saving energy and increasing plant capacity. In addition, PEF-treated products retain an improved colour and shape after drying.
Systems for development and industry
The technology also promises great potential in terms of yield and quality for the production of wine or extra virgin olive oil. The principle of cell disruption by PEF can be used here to extract the cell contents, especially value-giving substances such as polyphenols and aromatic basic substances. Improved extraction speeds up processing, increases quality and yield and results in energy and water savings.
The event was rounded off by the machine exhibition at Elea. The research and developmentoriented systems can treat up to ten litres in batch operation and up to 250 litres per hour in continuous operation. Industrial-scale systems have an hourly capacity of up to 100 tonnes for solid products on process belts or up to 5,000 litres for liquid products in continuous pipe treatment.