IN Brief:
- An August review examines cold plasma as a non-thermal processing technology for plant-based foods.
- Reactive oxygen and nitrogen species can inactivate microorganisms but may also modify proteins, lipids, carbohydrates, and other food components.
- Commercial adoption requires improved treatment uniformity, scale-up, process control, and product-specific safety and quality validation.
A new review published through NFS Journal examines cold plasma as a non-thermal treatment for plant-based foods, assessing its potential for microbiological control alongside the process and quality challenges that still restrict wider industrial use.
The paper, Cold plasma treatment in plant-based food processing: A non-thermal strategy for microbiological safety and quality preservation, was made available in August and focuses on the interaction between plasma-generated reactive species, microorganisms, and food components.
Cold plasma is produced by energising a gas so that it contains electrons, ions, excited molecules, and reactive oxygen and nitrogen species without raising the entire treated product to the temperatures associated with conventional thermal processing.
Those reactive species can attack microorganisms through several mechanisms at the same time, damaging membranes, proteins, genetic material, and other cellular components. The multi-target effect is one reason plasma has attracted sustained research interest as a possible decontamination technology.
The appeal to food processors is straightforward. Heat remains one of the industry’s most dependable controls for microorganisms and enzymes, but thermal exposure can also change flavour, colour, texture, vitamins, proteins, and other sensitive components.
A process capable of reducing contamination without applying comparable bulk heat could therefore be useful for products where fresh characteristics or heat-sensitive ingredients are important. Plant-based foods span particularly diverse matrices, however, and that diversity makes a universal treatment setting unlikely.
A leafy vegetable presents a very different surface from a protein powder, grain, fruit, plant-based milk, or meat analogue. Shape, moisture, composition, particle size, surface roughness, and product depth all affect how reactive plasma species reach the target.
Operating conditions are equally influential. Treatment time, voltage, power, frequency, gas composition, gas flow, humidity, electrode configuration, and distance between the plasma source and food can change both the quantity and type of reactive species produced.
The result is a process in which greater treatment intensity is not automatically better. Reactive species capable of damaging microorganisms can also react with proteins, lipids, carbohydrates, pigments, vitamins, and flavour compounds if exposure is excessive.
That gives processors a narrow optimisation problem: achieve the microbiological or functional effect required while keeping oxidation, discolouration, texture change, nutrient loss, and other unwanted reactions within the finished-product specification.
Plant proteins demonstrate both sides of the technology. Recent studies have examined cold plasma as a way to modify protein solubility, emulsification, foaming, gelation, and digestibility, potentially changing how an ingredient performs during formulation.
Those changes result from chemical and structural modification rather than a neutral physical treatment. Oxidation or nitration of amino-acid residues may alter protein structure and functionality, meaning an apparently useful processing effect still needs nutritional, toxicological, sensory, and shelf-life assessment.
Plant-based milk analogues provide another application area. Current research has considered plasma for microbial control and for modifying functional properties in systems containing dispersed plant proteins, but performance varies with the raw material and operating conditions.
Scale-up remains one of the most persistent barriers. Laboratory experiments typically treat small, well-positioned samples under carefully controlled exposure. A commercial line may need to handle kilograms or tonnes of irregular product while keeping treatment intensity uniform across the entire flow.
A plasma source positioned above a conveyor, for example, has to treat products despite differences in orientation, surface topography, loading depth, moisture, and line speed. Any shadowing or uneven exposure creates the possibility that some areas receive insufficient treatment while others experience excessive chemical modification.
Equipment integration introduces further requirements. High-voltage components, gas handling, guarding, hygienic design, cleaning access, controls, maintenance, and operator safety all have to fit within a production environment where uptime and sanitation are as important as the laboratory treatment result.
Different plasma-generation systems also produce different treatment geometries. Dielectric barrier discharge, plasma jets, corona systems, and other configurations vary in how energy and reactive species are delivered, making equipment selection product-specific rather than interchangeable.
Commercial adoption may consequently emerge through narrow applications before cold plasma becomes a general preservation technology. Surface decontamination, treatment of selected dry ingredients, packaging applications, or modification of specific protein functionality may be easier to validate than attempting to replace thermal treatment across an entire category.
Safety evidence will have to develop alongside the engineering. Processors need to know what reaction products are formed, how long reactive species persist, whether treatment alters allergens or nutrients, and what happens to the product through storage and digestion.
The research base increasingly supports cold plasma as a technically active food-processing tool, but activity is not the same as industrial readiness. Earlier reviews have similarly identified uniform treatment and scale-up as major challenges, particularly when moving away from controlled laboratory samples.
The latest review sharpens the same industrial question. Cold plasma can generate chemistry capable of reducing microorganisms and modifying plant-derived ingredients without conventional bulk heating, but factories need considerably more than proof that the chemistry works.
Routine adoption depends on delivering that treatment safely, uniformly, repeatedly, and economically at commercial throughput while proving that the food leaving the process has not acquired a different quality or safety problem in exchange for the one plasma was intended to solve.
