1. The study tested plasma-activated fog, not every cold-plasma process

Cold atmospheric plasma (CAP) covers multiple gas, device, and treatment configurations that generate reactive species without relying primarily on heat. The cited 2026 experiment specifically tested plasma-activated fog (PAF), not a universal CAP treatment. It examined five Listeria monocytogenes strains isolated from human, animal, and food sources, alone and in mixtures, first on nonselective agar and then on fresh-cut lettuce. Those materials and organisms define the evidence; the experiment does not establish effects against Salmonella, norovirus, or all food surfaces.

2. Reductions differed between agar and lettuce

On agar, a 30-second PAF exposure produced statistically significant reductions, ranging from complete inhibition to about 2.69 log CFU per plate depending on strain and tested concentration. The food test used artificially contaminated fresh-cut iceberg and romaine lettuce. After 10 minutes, the reported reductions were about 1.29 and 0.87 log CFU/g, respectively. The smaller reductions on lettuce illustrate why results from a laboratory medium do not predict performance on food. A measured reduction in an inoculation experiment is not proof that every pathogen was eliminated or that a product is safe.

3. Treatment also changed the fog’s chemical properties

Long-lived reactive oxygen and nitrogen species accumulated as treatment time increased, alongside acidification. The abstract reports nitrate rising from roughly 40 to 700 mg/L and pH falling from about 4.5 to 2.5 over the tested duration range. These observations make a blanket “no residue” or “only membrane damage” description inappropriate. Any effect of these chemical changes on flavor, texture, nutrients, packaging compatibility, or residues requires measurement in the specific food and process.

4. Expert perspective: microbial reduction is not process validation

A review of CAP combined with light-based treatments describes matrix-dependent efficacy and limited penetration as constraints, and notes that quality and long-term stability data remain scarce. The PAF researchers likewise call for further work across pathogens and food surfaces. The present result is therefore a reduction of Listeria on defined lettuce samples under laboratory conditions. It does not demonstrate a validated commercial sterilization process, compliance with a regulatory lethality target, control of cross-contamination, or a general consumer-safety guarantee.

Sources: Impact of decontamination by plasma-activated fog on Listeria monocytogenes mono- and mixed cultures on agar medium and foods / Integration of cold atmospheric plasma and light-based technologies for surface decontamination in nonthermal food safety applications