Pulsed Electric Field Food Processing Research Articles

Upscaling from benchtop processing to industrial scale production: More factors to be considered for pulsed electric field food processing

Pulsed electric field (PEF) processing of juice has been intensively studied with benchtop scale experiments. However, there is still limited information regarding critical factors to be considered for PEF efficacy in microbial reduction with PEF processing during pilot or commercial scale production of juice. In the present study, continuous benchtop (3.6–7.2L/h) PEF processing systems with co-field treatment chambers and bipolar square waveform pulses were used and simulated production conditions were tested for pomegranate juice. Microbial reductions of Escherichia coli, as affected by PEF process conditions (field strength, pulse width, pulse frequency, total treatment time, input energy), production conditions (flow rate, juice holding time and temperature), and juice properties (pH, conductivity, particulate), were investigated. Flow rate, PEF process parameters, production conditions, type of target microorganism, and properties of juice significantly affected microbial reductions by PEF treatments. E. coli ATCC 35218, a non pathogenic surrogate bacterium, exhibited higher resistance to PEF treatments than E. coli O157:H7 and E. coli K12 in pomegranate juice. Increase of a single PEF parameter (field strength, pulse width, pulse frequency, total treatment time, or energy input) is insufficient to achieve maximum microbial reduction. Optimal PEF treatment conditions for maximum microbial reduction depend on multiple factors including PEF processing parameters, production conditions and product properties. This study demonstrates that scale-up and validation studies in a specific PEF system for specific products are very important and necessary before successful commercial application of this novel technology is possible.

Pulsed electric field food processing –industrial equipment design and commercial applications

Pulsed electric field food processing –industrial equipment design and commercial applications

Condition monitoring of pulsed electric field food processing systems

Condition monitoring of pulsed electric field food processing systems

Pulsed Electric Field food treatment - scale up from lab to industrial scale

By pulsed electric field (PEF) application a permeabilization of plant, animal and microbial cells is achieved. The work has focused on identification of suitable processing and equipment parameters for a scale-up of PEF food processing as well as equipment design. Following the principles of process design, the principle action and the impact of processing parameters were identified. By modeling of inactivation kinetics and intensity distributions design guidelines for pulse generators and treatment chambers have been derived. Different treatment chamber configurations have been evaluated with regard to field homogeneity, flow pattern as well as cleanability. Equipment with an average power level of 5, 30 and 80kW was developed, allowing a treatment capacity of up to 10.000 l/h.The techniques scalability to an industrial level was shown. Along with application examples, the equipment design will be discussed.

Pulsed Electric Fields: Processing System, Microbial and Enzyme Inhibition, and Shelf Life Extension of Foods

Pulsed electric field (PEF) nonthermal food processing has been of growing interest owing to because of its excellent potential in providing consumers with microbiologically safe and fresh quality foods. Application of high-voltage electric fields at a certain level for a very short time by PEF not only inhibits pathogenic and spoilage microorganisms but also results in the retention of flavor, aroma, nutrients, and color of foods. This paper provides the most current information about PEF food processing. It reviews the systems for PEF processing and its effects on the inhibitions of microorganisms and enzymes and sensory and nutritional properties of foods. Regulatory issues of PEF processing are discussed as well

Use of circuit analysis simulations in pulsed electric fields food processing

In pulsed electric field (PEF) technology, treatment intensity during food preservation is defined by two processing variables: electric field and treatment time. These variables are evaluated by high voltage and current sensors located in the PEF system. Proper sensor location is very important in obtaining valid processing variables. This paper investigated the use of circuit analysis aided by PSpice™ (OrCAD™, Demo Version 9.1, Beaverton OR) software to evaluate the impact of voltage and current sensor location on the accuracy of electric field, pulse width, and energy calculations during PEF food processing. PSpice™ software was used to conduct the circuit analysis of a typical PEF electrical circuit and to analyze the behavior of the electrical transient delivered by the PEF circuit to a coaxial food treatment chamber. A saline solution ( σ=0.47 S/m at 20 °C) was used to verify the effect of sensor location in a PEF pilot plant-scale electric circuit. A pulse generator delivering slightly overdamped transients with charging voltages from 30 to 40 kV was used. Of the three electrical parameters, the most affected by improper placement of voltage sensors was the electric field, which can be measured at up to ∼10% higher than that experienced by the food in the PEF treatment chamber gap. Also, good agreement between the PSpice™ simulation and experimental results was verified. If the electrical behavior of the PEF system is not known and the sensors are inappropriately placed far from the PEF chamber, the validity of kinetic data and conclusions drawn on the effectiveness of certain processing conditions will be significantly limited.

Critical factors determining inactivation kinetics by pulsed electric field food processing

The potential to commercialize the non-thermal pulsed electric field (PEF) technology as a new method to preserve food products has caught the attention of the food industry that wishes to fulfil consumers demands for fresh products. In recent years, numerous research groups have demonstrated the possibility to inactivate a range of microorganisms both in buffer systems and in food products using different PEF systems. In this review, we survey the critical process factors and main characteristics of food products that determine the microbial inactivation kinetics.