Plasma-activated water (PAW) is generated by treating water with cold atmospheric plasma (CAP) using controllable parameters, such as plasma-forming voltage, carrier gas, temperature, pulses, or frequency as required. PAW is reported to have lower pH, higher conductivity, and higher oxygen reduction potential when compared with untreated water due to the presence of reactive species. PAW has received significant attention from researchers over the last decade due to its non-thermal and non-toxic mode of action especially for bacterial inactivation. The objective of the current review is to develop a summary of the effect of PAW on bacterial strains in foods as well as model systems such as buffers, with a specific focus on fruit and vegetables. The review elaborated the properties of PAW, the effect of various treatment parameters on its efficiency in bacterial inactivation along with its usage as a standalone technology as well as a hurdle approach with mild thermal treatments. A section highlighting different models that can be employed to generate PAW alongside a direct comparison of the PAW characteristics on the inactivation potential and the existing research gaps are also included. The mechanism of action of PAW on the bacterial cells and any reported effects on the sensory qualities and shelf life of food has been evaluated. Based on the literature, it can be concluded that PAW offers a significant potential as a non-chemical and non-thermal intervention for bacterial inactivation, especially on food. However, the applicability and usage of PAW depend on the effect of environmental and bacterial strain-based conditions and cost-effectiveness.

Two low equivalent weight perfluorosulfonic acid (PFSA) polymers (825 EW and 733 EW) were successfully electrospun into nanofibers by adding as little as 0.3 wt% of high molecular weight poly(ethylene oxide) as a carrier polymer. The electrospun fiber morphology transitioned from cylindrical filaments to flat ribbons as the total concentration of PFSA + carrier in solution increased from 5 wt% to 30 wt%. PFSA nanofiber mats were transformed into defect-free dense membranes using a four-step procedure: (i) annealing the PFSA polymer during which time intersecting fibers were welded to one another at cross points (ii) mechanically compacting the mats to increase the volume fraction of nanofibers to ∼75%, (iii) imbibing an inert polymer, Norland Optical Adhesive (NOA) 63, into the mats (to fill entirely the void space between nanofibers) and then crosslinking the NOA with UV light, and (iv) removing the poly(ethylene oxide) carrier polymer by boiling the membrane in 1.0 M H₂SO₄ and then in deionized water. The resulting membranes exhibited higher proton conductivities than that of commercial Nafion 212 membrane (0.16 S/cm at 80 °C and 80% relative humidity and 0.048 S/cm at 80 °C and 50% relative humidity for a membrane with 733 EW nanofibers), with low water swelling (liquid water swelling of 18% for membrane with high conductivity). The proton conductivity of both EW nanofiber composite membranes increased linearly with the PFSA nanofiber volume fraction, whereas gravimetric water swelling was less than expected, based on the volume fraction of ionomer. There was a significantly improvement in the mechanical properties of the nanofiber composite membranes, as compared to recast homogeneous PFSA films.