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Pulse Electric Field (PEF)

General Information


Pulse electric field technology have been under research for almost 50 years. First appeared as potential way to pasteurize milk in the food industry. The equipment needed is similar to radar, the development of radar technology has play a role in the development of PEF. The developments in electronics and energy technology enables high potential for the development of this close to the market food technology. In the year 2000 the commercialization of solid state pulsed power systems leads to better access to the technology in the food industry.

(Muredzi, 2012)


  • The technology enables cold processing of food keeping the nutritional value and most of the properties of the product.
  • Economical and efficient improve of energy use.
  • It provides microbiologically safety and enables minimally processed food.
  • Mass transfer rates are also improvement.
  • Pretreatment of food in an ecological and gentle way is enabled.
  • No correlation with thermal or not thermal treatments (potential synergic strategies with conventional methods)

(Toepfl, Siemer, Saldanaña & Heinz 2014)


  • Most Enzymes and spores are not affected, therefore there is a need of refrigeration.
  • Limitation on the peak power generation capacity
  • Electric arcing producing unwanted products due to gas bubbles (pressurization needed).
  • Voltage limitation for not liquid products due to the arching voltage of air (oil filled chamber recommended)
  • Complexity and high cost of pulses. High initial investment.
  • Insufficient kinetics and inquorate treatment delivery assessment.

(Muredzi, 2012)


The base of the technology is the electroporation phenomena. The electric field enlarge the pores of the cells membranes killing the cell and realising their content.

(Muredzi, 2012)

Electroporation Steps:

1) Increase in the transmembrane potential. The cell membrane is consider as a capacitor filled with dielectric material of low electrical conductance. Accumulation of appositive polarity charges in each of the two sides of the membrane leads to perpendicular transmittance of about 10mV.

2) Start of the pore formation. The number of pores depends on transmembrane potential and other influencing factors being the electric field strength one of the most important. Others are temperature and membrane fluidity. Electro compression forces produced at both sides of the membrane due to the attraction of appositive charges leads to an increase of permeability, but not all the cells are electro pored at the same time point out the formation of hydrophilic porous.

3) Evolution in the in the number and size of the pore formed.

4) Recovery of membrane´s integrity after EP or circulation of molecules across the envelope if the electroporation is irreversible. There are two phases: First one about reducing the size till 0.5 rp taking from micro seconds to minutes and the second phase, the complete resealing taking from minutes to hours.

(Toepfl, Siemer, Saldanaña & Heinz 2014)

Description of techniques

  • The fundamental technique are brief pulses of a strong electric field. The substance is between two electrodes. The generation of PEF requires a high discharge of energy in short period of time.
  • Typical ranges: 10 ns – 0.02ns, 35-50 kV/cm
  • Above 15 kV/cm vegetable cell are killed (35KV/cm are used for disinfection.
  • Cell membrane permabilization from stress induction at 1-2kJ/kg to plant cell permeabilization at 1-10kJ/kg with continuous operability in this short time.
  • Waste free, cost effective food reservation without losing the high level of quality, lower operating temperatures, short resident time, cut quality improvement, raw material usability and energy savings.

(Muredzi, 2012)

  • System Components:

Pulse Forming Network (power supply with the ability to charge voltage up to 60kV, switches, capacitors, inductors, resistors and treatment chamber).

The treatment chamber has a major role concerning its level of electric resistance (influenced by the geometry of the chamber); it can be batchwise or continues flow operation (parallel plates most effective).

(Toepfl, Siemer, Saldanaña & Heinz 2014)

Flow chart: Controlling and Monitoring System, High Energy pulse generator, treatment chamber, pump, temperature controls, Cooling coil (starting from Raw materials and finishing with treated product)

(Muredzi, 2012).

PEF Flow chart.jpg

PEF Flow chart. Source: Intech, 2015

There are two main configurations, batch wise and continuous treatment.

Batchwise: Flow energy possibility 110 V AC pulses of 2 micro seconds and up to 100 KV/cm high voltage and circular treatment chamber.

Continuous treatment: 30 kV DC generator, coaxial chamber, devise for pumping, flow control and recording (cooling jackets are sometimes needed), 180 l/h max capacity.

  • Process variables: Electric field (wave form, strength and distribution), temperature (35-50°, organisms more tolerant at lower temperature, exothermic process, growth temperature is reference for low level), pressure (inhibit formation of bubbles above 20 KV/cm) , time of exposure (1000 times/sec flowing through several chambers, static treatment for solids is possible, balance between processing time and exposure) and high power sources (depends on the voltage wave form and the available elements in the electric system; basic pulse power system, circuits with voltage multipliers, pulse forming circuits, network with pulse forming circuits).

(Muredzi, 2012)

  • Treatment medium factors: Conductivity (high conductivity make the voltage peak required difficult to reach), pH (influence on the regenerative capacity of the cell, low pH can be beneficial for some cells).

(Toepfl, Siemer, Saldanaña & Heinz 2014)

Changes in process (Operation Unit Applications)


PEF in pasteurization is most effective with vegetative bacteria, yeast and molds, enabling up to 70% more yield than conventional methods and additional to the benefits of avoiding high temperatures and long processing times. (Muredzi, 2012)

More lethal under parameter of low ionic strength, low conductivity and high resistivity. Antimicrobials synergies are possible. Sampedro et al (2013) have calculated the PEF pasteurization about 40% more expensive than the conventional one, having the larger cost related with the initial capital investment (Griffiths & Walking-Ribeiro 2014).

Juice processing results: Carrot almost 70% more yield (less than 15% for orange) and 15% more dry matter, 520 V/cm and 100 microseconds (Muredzi, 2012).


High intensity pulsed electric fields or thermal treatments effects on the amino acid profile of a fruit juice-soymilk beverage during refrigeration storageOriginal Research Article

Innovative Food Science & Emerging Technologies, Volume 16, October 2012, Pages 47-53

M. Morales-de la Peña, L. Salvia-Trujillo, T. Garde-Cerdán, M.A. Rojas-Graü, O. Martín-Belloso


Applications for Juice, sugar and oils in an easy way. The processing time reduction is the major advantage due to the improved mass and heat transfer capacities (60% less time needed in some cases).

(Griffiths & Walking-Ribeiro 2014)


Effect of pulsed electric fields and high voltage electrical discharges on polyphenols and proteins extraction from sesame cake

Júlia Ribeiro Sarkisa, Nadia Boussettab, Christelle Blouetb, Isabel Cristina Tessaroa, Ligia Damasceno Ferreira Marczaka, Eugène Vorobievb


With many of the drying operations in place quality deterioration is observed either due to high processing temperatures or slow drying rates. PEF enhances the mass transfer enabling a faster processing together with a higher level of quality (avoiding thermal degradation).The yield in fruits around 30 % when exposed to low electric fields. There are also successful results for meat and fish (about 30% improvement in mass transfer), reducing the residence time, i.e. red peppers from 360 to 220 minutes. Use about 10 KJ/kg

(Toepfl, Siemer & Heinz 2014)


Comparative evaluation of the effects of pulsed electric field and freezing on cell membrane permeabilisation and mass transfer during dehydration of red bell peppers.

Innovative Food Science & Emerging Technologies, Volume 4, Issue 2, June 2003, Pages 177-188

B.I.O. Ade-Omowaye, K.A Taiwo, N.M. Eshtiaghi, A. Angersbach, D. Knorr


PEF technology could be used in the food industry to improve the aromatic quality due to the low effect in volatile compounds.

(Garde-Cerdán et al. 2013)

Other heating processes/Peeling and Cutting

PEF has a softening effect that reduce the energy needed for cutting, avoiding pre heating processes and less intense post treatment due to enzymes inactivation. This also leads to a higher level of quality avoiding by avoiding thermal degradation.

(Toepfl, Siemer & Heinz 2014)


Feasibility of using pulsed electric field processing to inactivate enzymes and reduce the cutting force of carrot (Daucus carota var. Nantes)Innovative Food Science & Emerging Technologies, Volume 26, December 2014, Pages 159-167

Sze Ying Leong, Lena-Katrin Richter, Dietrich Knorr, Indrawati Oey


The color extraction can be achieved at lower temperature. Preservation of color is also a highlight.

(Toepfl, Siemer & Heinz2014)


Color and viscosity of watermelon juice treated by high-intensity pulsed electric fields or heat

Innovative Food Science & Emerging Technologies, Volume 11, Issue 2, April 2010, Pages 299-305

Ingrid Aguiló-Aguayo, Robert Soliva-Fortuny, Olga Martín-Belloso

Energy Savings

In a general way, energy savings are enabled in the operation due to the enhanced mass and heat transfers in the different processes in which PEF technology is used. As the power is higher but for shorter time, the driving force of the process can be enhanced and the energy use maximized, the problem will be on the capacity of the system to generate the power peaks of the pulses.

(Muredzi, 2012)

The best energy performance for potatoes processing with PEF with about a low residence time and the lowest level of KJ per Kg.

(Toepfl, Siemer & Heinz 2014)

Extraction process of sugar cane shows energy saving of 50%. Use about 10 KJ/kg

(Toepfl, Siemer & Heinz 2014)

Figure Energy required for cell disintegration of potato, (Toepfl et al. 2014, p.105)

Recent Cases:

Cost analysis of commercial pasteurization of orange juice by pulsed electric fields

Innovative Food Science & Emerging Technologies, Volume 17, January 2013, Pages 72-78

F. Sampedro, A. McAloon, W. Yee, X. Fan, H.Q. Zhang, D.J. Geveke

Change in Energy Distribution

Substitution of thermal operation for PEF operation, reducing the demand of thermal energy and raising the one of electric energy. This lead to lower temperature use in the process leading to use of less intense thermal energy. The generation of pulsed electric field may imply a major demand of electricity power but the magnitude of this demand is highly depended on the configuration of the pulse generation system. Reaching the peak power needed is the major challenge and the main cost issue. Typical average power of PEF units is 30-400kW. The actual demand of power relies on the design of the generator of the discharge. For industrial applications 40-100 kV and 100 A – 5kA. Life time of 10^12 pulses for semiconductors at optimal operation conditions (out of this conditions, it can be drastically lower).

(Toepfl, Siemer, Saldanaña & Heinz 2014)

The system transform electrical power from a low, utility level into pulsed high intensity electric field. Slow charging and fast discharging, the electric strength depends on the distance between the electrodes.

(Toepfl, Siemer, Saldanaña & Heinz 2014)


  • Garde-Cerdán, T., González-Arenzana, L., López, N., López, R., Santamaría, P., López-Alfaro, I. (2013) 'Effect of different pulsed electric field treatments on the volatile composition of Graciano, Tempranillo and Grenache grape varieties', Innovative Food Science & Emerging Technologies, 20(October), pp. 91-99.
  • Griffitths M. W., Walking-Ribeiro, M. (2014) ' Part II: Chapeter 7 Pulse Electric Field processing, in Sun, D. (ed.)Emerging Tehcnologies for Food Processing. UK: Academic Press, pp. 115-138.
  • INTECH (2015) EPG DIAGRAM , Available at: (Accessed: 15th March 2015).
  • Muredzi, P. (2012) 'Chapter 2: Pulse Electric Field processing', in Aleman, M. (ed.) Emerging Non-thermal Food Processing Technologies. USA: CBH books, pp. 19-57.
  • Sampedroa, F., McAloonb A., Yeec W., Fand X., Zhange H.Q., Geveke D.J. (2013) 'Cost analysis of commercial pasteurization of orange juice by pulsed electric fields',Innovative Food Science & Emerging Technologies, 17(January ), pp. 72–78.
  • Toepfl S., Siemer, C., Heinz V. (2014) ' Part II: Chapeter 8 Pulse Electric Field processing, in Sun, D. (ed.)Emerging Tehcnologies for Food Processing. UK: Academic Press, pp. 147-152.
  • Toepfl S., Siemer C., Saldanaña G., Heinz V. (2014) ' Part II: Chapeter 6 Pulse Electric Field processing, in Sun, D. (ed.)Emerging Tehcnologies for Food Processing. UK: Academic Press, pp. 93-108.