Technology for healthier hot chips

Hot chips (aka French fries) may become healthier and more environmentally friendly if a three-month trial of German Pulse Electric Field (PEF) technology at the University of Otago proves successful.

The pilot program trial is a part of a Ministry for Business and Innovation funded Food Industry Enabling Technology program worth $16.8 million over a six-year period, ending in 2021.

What is PEF processing?

PEF processing is an efficient non-thermal food processing technique where very short (microseconds) high-voltage pulses in the order of 10 to 60 kV are applied to products. The high-voltage pulses applied induce pores in cell membranes, causing a loss of barrier function, leakage of intracellular content and loss of vitality.

PEF processing is quick, flexible, energy efficient and, because heat is minimised, products have a longer shelf life while maintaining better nutritional value than with traditional food processing techniques.

Despite its targeted effect on cell membranes, PEF does not affect vitamins, flavours or proteins. This allows microbial decontamination of heat-sensitive liquids while retaining their sensory qualities and functional value.

As PEF processing affects the cell membrane it can be used to enhance the extraction of pigments or bioactive compounds from food, increasing their yield and quality or to kill microorganisms as an alternative to the pasteurisation of bulk liquids, such as fruit juices and milk.

PEF, potatoes and the University of Otago

Sending electric pulses through the chip, it is claimed that PEF technology will result in raw fries being bendier and unbreakable, reduced potato wastage and less fat absorption as the chips cook.

Elea PEF processing equipment is to be put to the test for large-scale French fries production at the University of Otago.

The electric field being pulsed through uncut potatoes during processing alters their microstructure, which results in a more controlled release of sugar, more uniform colouration and reduced oil uptake. It also enhances processing as the softer texture makes the potatoes easier to cut, meaning there is less waste, the ability to develop new shapes (such as lattice cut) and increased knife durability (up to 60%).

Using PEF systems instead of preheaters has several advantages for potato processing. PEF treatment improves cut quality and significantly reduces French fries breakage. Water and energy consumption are reduced; blanching, drying and pre-fry times are shortened. Furthermore, the leaching of sugars is improved. The treatment can also reduce frying oil absorption and fat content up to 50%.

PEF benefits for French fries manufacturing

• Replacement of thermal preheater
• Instant start-up and shutdown
• Continuous, minimum energy consumption
• Less starch in process water
• Smaller footprint
• Reduced blanching and frying time
• Reduced ambient heat.

PEF benefits for French fries quality

• Texture softening
• Higher yield (less breakage)
• Longer fries
• Reduced oil uptake
• Smoother cut
• Increased knife durability
• Possibility to develop new cuts and shapes.

PEF technology is not limited to potato processing but has a wide variety of applications across many food processing industries.

Image credit: ©stock.adobe.com/au/marcelokrelling