Non-Thermal Processing Techniques in Food Preservation

Non-thermal processing techniques are an expanding field in food preservation, seeking to extend shelf life and ensure safety while maintaining nutritional and sensory qualities. Conventional heat treatments can degrade heat-sensitive vitamins, proteins and flavours; non-thermal approaches, by contrast, rely on physical forces—such as high hydrostatic pressure, pulsed electric fields, pulsed light or ultrasound—to inactivate microorganisms and enzymes. Pulsed electric fields employ microsecond bursts of high voltage to permeabilise cell membranes, leading to microbial inactivation with minimal heating. High hydrostatic pressure subjects packaged foods to pressures up to 600 MPa, inactivating pathogens by disrupting cellular structures. Pulsed light and cold plasma offer rapid, surface-oriented microbial control via intense light or ionised gases, respectively. Ultrasound utilises cavitation effects to disrupt microbial cells and enhance mass transfer. These methods can be applied to a broad range of products—from fruit juices and dairy to meat and seafood—supporting global demands for safe, fresh-like foods. Furthermore, integrating multiple non-thermal processes can yield synergistic effects, reducing treatment intensity and energy consumption while achieving regulatory targets for microbial safety.

Research from Nature Portfolio

Recent studies have elucidated the structural targets of pulsed electric fields at the nanoscale. One seminal investigation combined atomic force microscopy and electron microscopy to show that PEF not only permeabilises bacterial cell membranes but also induces disorganisation of the cell wall in vegetative cells and partial destruction of spore coat proteins. These findings reveal that electro-induced cell wall alterations are central to microbial inactivation and suggest tailored field parameters to address spore-forming pathogens. Such mechanistic insights inform optimisation of PEF protocols for diverse food matrices and enhance predictions of microbial resistance.

Non-Thermal Processing Techniques in Food Preservation publication trend

The graph below shows the total number of articles in non-thermal processing techniques in food preservation across all publications each year (not limited to Nature Index journals).

Technical terms

Non-thermal processing: Techniques that inactivate microorganisms and enzymes without elevated temperatures by using physical or mechanical forces.

Pulsed electric fields (PEF): Application of short, high-voltage pulses to food placed between electrodes to permeabilise microbial cell membranes.

High hydrostatic pressure (HHP): Uniform application of very high pressures to packaged food to disrupt cellular structures and inactivate pathogens.

Pulsed light (PL): Exposure of food surfaces or packaging to intense, short bursts of broad-spectrum light for microbial inactivation.

Membrane permeabilisation: The formation of transient or permanent pores in cellular membranes, leading to loss of viability in microorganisms.

References

1. Sustainable food chains designed for optimised resource use: Optimising downscaled food chains for sustainable resource use: A comprehensive case study on tomato juice. Journal of Cleaner Production (2024).
2. Cell wall as a target for bacteria inactivation by pulsed electric fields. Scientific Reports (2016).
3. Non-thermal Technologies for Food Processing. Frontiers in Nutrition (2021).
4. Applications of Pulsed Light Decontamination Technology in Food Processing: An Overview. Applied Sciences (2020).