PEF technology for mild preservation of liquid foods and beverages

Pulsed Electric Field (PEF) processing inactivates micro-organisms in juices without affecting valuable compounds such as vitamins and proteins.

Pulsed Electric Field (PEF) processing for fresh juices is an efficient nonthermal food processing technique using short, high voltage pulses. These pulses induce poration of microbial cells, leading to microbial inactivation.

PEF processing is an excellent technology for mild preservation of liquid foods and beverages. PEF inactivates micro-organisms in juices, but leaves valuable compounds, such as vitamins and proteins, unaffected. The Pulsemaster PEF systems have treatment capacities from 50 liters (14 US gallon) up to 5,000 liters (1320 US gallon) per hour per system for microbial inactivation.

The required treatment time is less than a second. The pulses are applied at repetition rates of up to a maximum of 1000 pulses per second to allow sufficient treatment of all volume elements. By exposing the cell to a pulsed electrical field the cell membrane becomes punctured. The membrane is punctured with small pores of 50-100 nanometer each. This effect is called electroporation, which is the loss of the cell’s barrier function allowing access to the cell’s valuable contents. Loss of cell membrane barrier function causes microbial death. Electroporation takes places after 1 microsecond (µs). The process is quick, flexible, energy-efficient and because heat is minimized, products have a longer shelf life whilst maintaining better nutritional value than with traditional food processing techniques.

The Pulsemaster PEF systems can also be applied to improve other drying, cutting, peeling and pressing processes. Examples are the drying of sweet peppers and grapes, the peeling and cutting of tomatoes and the pressing of fruits, vegetables and olives.