PEF: How It Works

Pulsed Electric Field Processing: An Efficient Technique

Pulsed electric field (PEF) processing is an efficient, non-thermal food processing technique that utilizes short, high-voltage pulses. These pulses induce poration in plant, animal, and microbial cells, leading to cell disintegration and microbial inactivation. A higher treatment intensity is necessary for microbial inactivation than for mere cell disintegration.

Pulsed Electric Field Technology Explained

Pulsed electric field technology involves the application of microsecond high voltage pulses that induce pores in cell membranes, causing a loss of barrier function, leakage of intracellular content and loss of vitality. Possible aplications are cold extraction and pressing, and drying and freezing enhancement

This technology involves applying microsecond, high-voltage pulses ranging from 10 to 60 kV. These pulses create pores in cell membranes, leading to a loss of barrier function, leakage of intracellular contents, and loss of vitality.

Continuous Treatment in a Chamber

The treatment occurs continuously in a chamber with multiple electrodes. For microbial inactivation of liquids and semi-viscous liquids, the pulse generator is combined with a PEF treatment chamber. Products, whether liquids, semi-viscous liquids, or solids, are pumped or transported through the chamber, exposing them to high-voltage pulses. The treatment time is less than a second, with pulses applied at rates up to 500 pulses per second. Factors such as electrical parameters, product temperature, and recipe impact treatment intensity.

Pulsemaster Conditioner: An Advanced Solution

Pulsemaster’s Conditioner represents an advanced, energy-efficient PEF concept. It can easily integrate into existing lines due to its continuous process and low space requirements. The new equipment offers improved pulse treatment with a compact, modular pulse generator. For solid cell disintegration, it combines a robust, hygienic transport system with a PEF treatment chamber.

Proven Track Record in the Food Industry

Pulsemaster’s pulse generators have a proven track record in the food industry and research. The Marx solid-state typology, used in all industry PEF systems for producing French fries and crisps, originated from Pulsemaster’s German engineering expertise. This typology ensures better pulse control and high reliability. Pulsemaster offers a range of robust PEF systems, covering power ranges up to 100kW per system, adhering to regional certification requirements and built for continuous operation.

Puncturing the Cell Membrane: Electroporation

Electroporation of plant and animal raw materials enhances mass transport processes such as extraction, drying, freezing and pressing, saving time and money and increasing value.

The cell membrane, a thin semi-permeable phospholipid bilayer, acts as a barrier for ion and macromolecule transport. Exposure to a pulsed electric field punctures this membrane, creating small pores (50-100 nanometers each), a process known as electroporation. This quick, flexible, and energy-efficient process, minimizes heat, extending shelf life and maintaining nutritional value better than traditional methods.

PEF: A Targeted and Clean Process

Results of PEF processing are enhanced drying, extraction and pressing, fresher food products with a higner nutritional value and longer shelf life, and the saving of time, energy and water.

PEF, or electroporation, punctures cell membranes of any size. This targeted, gentle, and clean process leads to increased yield and better preservation of pigments, antioxidants, and vitamins. It helps in making healthier products last longer. Cells typically measure 20-100 micrometers, bacteria 2-10 micrometers, and pores created are 50-100 nanometers. More pulses create more stable pores. Pulsemaster’s Conditioner can operate at a maximum of 500 pulses per second.

Impact on Cell Membranes and Microbial Death

Membrane disruption occurs when the induced potential exceeds 1 V in many cellular systems, corresponding to an external electric field of about 10 kV/cm for E. coli. Electroporation becomes irreversible above a certain threshold. Despite its targeted effect on membranes, PEF does not affect vitamins, flavors, or proteins, allowing microbial decontamination of heat-sensitive liquids without compromising their sensory and functional values.

Influence of the Food Matrix

The dielectric strength of the food matrix has a significant influence on the applicability of pulsed electric field technology

The food matrix’s dielectric strength significantly influences PEF’s applicability, as dielectric breakdown must be avoided. Air bubbles, which can’t withstand high electric fields, should be removed, especially for microbial inactivation. Vacuum degassing or pressurizing the treatment media during PEF processing helps minimize air bubble presence. For solid foods, removing air encapsulations is necessary to prevent electric discharges, and foam-forming products may be unsuitable for PEF treatment.