Pulsed Electric Field to Better the Fruit and Vegetables

To improve the condition of Fruit and Vegetables  for processing and maintain nutritional value European researchers have been giving fruit and vegetables electric pulses. Treated tomatoes are easier to peel and no longer need to be plunged in boiling water, saving energy. The technique also preserves fruit and vegetable nutritional values. Scientists believe that this method is particularly well suited to small and medium companies specialized in food processing. 

In Cahir, South West Ireland, Cornelius Traas' family-run farm produces 600 tons of potatoes annually which are processed into juice, cider and vinegar. They are testing treating the fruit with a pulsed electric field as part of the European research project, FieldFood.

The electric pulses perforate the fruit cells and simplify extraction, it could also kill microbes, prolonging fresh juice conservation. 

To prove the commercial advantages of the technology within the agri food industry. Elisa Luengo, Food Processing Researcher, explains that the total energy needs are very low, "treating one kilo of tomatoes requires less energy than when heating a litre of water for it's temperature to increase by one degree". 

Pulsed electric field (PEF) is a novel technique able to permeabilize cells presented in fruit and vegetable tissues without an important increase of the product temperature and avoiding an excessive deterioration of the tissue. This chapter summarize the fundamentals of this interesting technology and its main applications in vegetable and fruit processing. PEF has been proposed for enhancing or assisting different processing operations, such as solid-liquid extraction (e.g. extraction of ingredients, winemaking, sucrose extraction, food waste and by-product revalorization), mechanical extraction (e.g. juice expression, mechanical oil extraction), cutting/slicing (e.g. potato snack production), dehydration (e.g. hot air drying, osmotic dehydration, freeze-drying), freezing or peeling. From a general point of view, benefits of PEF can be summarized in

(1) improve process yield

(2) increase process velocity

(3) improve food quality (e.g. reduce fat up take, reduce impact on sensory properties, increase health related compounds)

(4) decrease the intensity of other processing variables (e.g. temperature, grinding degree) and/or

(5) increase the cost efficiency of the operation (e.g. reduce energy consumption). Although some PEF applications have been scaled up to pilot-industrial necessities, only a few have been tested in a real production environment or are used nowadays at industrial level, such as the PEF pretreatment of potato in snack production.