Above and below: Potatoes being treated using Pulsed Electric Field (PEF) system (Elea GmbH) in an industrial setting. (Photo courtesy of potatopro.com)
Consumer interests in healthier and fresher foods have driven much of the interest in advanced preservation methods, such as pulsed electric field (PEF) processing. Pulsed Electric Field (PEF) is a unique non-thermal method of inactivating microorganisms, including many of the common food pathogens, without heating the product to the usual pasteurization temperatures. The destruction or inactivation of the microorganism is achieved by the breakdown of the microorganism’s cell membranes during exposure to electric fields.
While PEF has been widely used across the food industry from juices, wine, and olives mainly as a means for sterilization, preservation and retaining nutritional values. For potatoes processors the use of PEF treatments is for cell disintegration, in place of the preheater operation. In this application, pulsed electrical fields create micro-pores in cell membranes, which enable the loss of primarily of liquid contents such as asparagine and reducing sugars but not starch loss. Structural and textural changes are also realized, reducing wear on cutting blades, increasing line yield and reducing water usage. The benefits of this processing method have seen many food processors across various industries incorporate this technology into their processing lines. A recent report by Technavio (January 2020) stated the global food industry pulsed electric field (PEF) systems market is poised to grow by USD227.52m during 2020-2024, progressing at a CAGR of about 24% during the forecast period.
What is PEF?
Originally used in the MedTech sector, Pulsed Electric Field (PEF) is now breaking new grounds in the food industry. Pulsed Electric Field (PEF) is a method for processing cells by means of brief pulses of a strong electric field. The electric field perforates the cell walls of the food creating micro holes that allow asparagine and reducing sugars to be washed out of the potato in cold water wash. In most cases, eliminating/reducing the need to blanch in the preparation of products prior to further processing. As blanching can lead to starch loss decreasing yield, by avoiding this step processors minimize the loss.
PEF technology aims to offer consumers high-quality foods and is considered superior to traditional thermal processing methods. Potato Processors are finding the benefits of using PEF technology in the production of French fries and potato chips: Lower acrylamide, lower oil content, higher yield, crunchier texture and lower processing costs. In addition to increased food quality, PEF also leads to energy and environmental savings.
Potatoes are considered excellent conductors because they are uniformly solid, contain about 80 per cent water and are rich in potassium. By permeabilizing cell membranes, PEF enables tissue softening resulting in the improved cutting of potatoes, higher product quality and increased process capacity. Through PEF processing osmotic pressure (turgidity) is reduced by permeabilizing the cell membranes, which enables cutting at an optimal product texture. French fry processors realize less breakage and shattering, producing longer, thinner French fries with smooth surfaces and sharp edges.
This improved cutting is also evident for potato chip manufacturers with smoother surfaces and less coloration. The smoother cuts mean more starch is retained by the potato cells on the surface of the chip that when fried result in crunchier chips. PEF systems are an excellent alternative for blanching. PEF technology not only results in superior cut quality and better drying efficiency, but also improves the leaching of sugars. The pulsed electric field causes tiny pores in the potato cell walls which facilitates sugar leaching. This is good news for public health, because less sugar means less acrylamide formation during the baking or frying of potato products. Furthermore, PEF leads to a significant reduction in the fat content after frying, providing the potential to produce low-fat french fries and chips.
(Article courtesy of www.potatobusiness.com )