Stephan Töpfl: “PEF is Seen as Standard in the French fry Industry”
Pulsed Electric Fields (PEF) process is increasingly being used in the production of potato and vegetable snacks. The benefits of the process are based on an effect known as electroporation, which has the cell membrane as its target.
A membrane engulfs all cells, separating them from their surroundings. When an external voltage is applied, a charge accumulates at the membrane, causing the potential to rise. This causes an electrical compression of the cell membrane, resulting in the formation of a pore.
Plant cells, such as potato cells, soften when exposed to PEF because their internal cell pressure decreases (turgor). Cutting is improved as a result of controlled texture softening of tubers, resulting in less starch loss and thus increased product yield. Reduced feathering also reduces oil uptake during frying. Facilitated moisture release allows reduced frying time and temperature, which can lead to increased production capacity and improved product appearance.
Potato Busines: How can the potato processors who adopt PEF technology make significant cost savings?
Stephan Töpfl, ELEA: PEF triggers tissue softening, which improves cutting and reduces tissue breakage, increases yield, and reduces oil uptake.
Can you give us more details about the benefits the improved cutting achieved by using PEF delivers? Please touch upon yield, blade wear, and oil uptake.
The final product yield is increasing, as less starch is lost in processing water streams. How much is dependent on product shape, for French fries typical yield increase is 1% and for potato chips 1 to 2%. Blade lifetime is multiplied by a factor of up to three. Oil uptake is reduced by up to 10% for French Fries and up to 18% for potato chips. E.g, on a 1,500 kg/h potato chips line oil savings of up to 175 tons per year have been achieved.
Why is PEF a superior process to regular blanching or traditional preheating?
PEF is using electric energy; its major benefit is the volumetric and instant effect. Small and large tubers are treated the same, without the need for residence time. In comparison to thermal treatment very little energy is required, as a ballpark number of 1 kWh per ton of product is applied. Hence PEF contributes to using less thermal energy and reducing fossil fuels use.
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