# Processing Fresh-Cut Potatoes Using Non-Thermal Technologies and Edible Coatings
## 5 Emerging Processing Technologies: Operating Principles and Examined Parameters
### Miscellaneous Technologies
#### 5.5.3 Plasma Treatment  
Non-thermal plasma (NTP) decontamination technology has emerged as a prominent and verified non-thermal processing method for microbial inactivation. NTP is a state of ionized gas characterized by the presence of electric fields, charged particles, ultraviolet photons, and reactive species, including reactive oxygen species (ROS) and reactive nitrogen species (RNS) [171]. The generation of plasma occurs when electrical energy is applied to a gas present or flowing between two electrodes with a high electrical potential difference, leading to gas ionization as a result of free electrons colliding with gas molecules [172]. Various methods are employed for generating plasma in food processing, and these methods are broadly classified into dielectric barrier discharge (DBD), plasma jet (PJ), corona discharge (CD), radiofrequency (RF), and microwave (MW) [172; 173]. ROS and RNS are identified as the primary bactericidal agents in plasma inactivation [174]. These components contribute to the breakdown of cell membranes, DNA, and microbial proteins [175; 176; 177]. NTP offers several advantages for food processing, including low application costs, short treatment times, and broad applicability across various food types, including packaged foods. Additionally, NTP is considered an environmentally sustainable technique, as it avoids the use of chemicals and requires minimal energy, making it a promising technology for enhancing microbiological quality, decontaminating packaging materials, and sterilizing food contact surfaces [177]. In an industrial setting, plasma treatment can be used for surface sterilization of fresh-cut potatoes, reducing microbial contamination and enzymatic browning. It is particularly effective when combined with other methods to further enhance shelf life. However, there are disadvantages to plasma treatment as well. One challenge is the potential for oxidative damage to the sensory and nutritional quality of certain foods due to the high reactivity of ROS and RNS, which can affect the texture, color, and flavor of delicate food products. Furthermore, the effectiveness of plasma can be limited by its penetration depth, as it primarily acts on the surface, making it less effective for foods with complex shapes or dense structures [178]. This technology has been explored for the decontamination of various fresh fruits and vegetables, including grapes, tomatoes, vegetable leaves, strawberries [179; 180; 181; 182]. Plasma-processed air (PPA) is an indirect non-thermal plasma treatment involving remote exposure. This treatment is produced by a discharge device and then indirectly supplied to the samples undergoing exposure. [PERSON] et al. (2017) explored the potential application of PPA in fresh-cut potatoes and found that the activity of PPO and peroxidase (POD) was reduced by 77% and 89%, respectively, after exposure of fresh-cut potatoes to PPA for 10 min [94]. Cold plasma (CP) is formed when ionized gas is generated with relatively low energy (1-10 eV) and electronic density (up to 10\({}^{10}\) cm\({}^{-3}\)) [183]. In CP, there exists a thermodynamic non-equilibrium between electrons and heavy species, causing a temperature difference between them due to the significantly lighter nature of electrons compared to ions and neutral molecules. The gas maintains a low temperature as the cooling of ions and uncharged molecules is more effective than energy transfer from electrons [184]. [PERSON] et al. (2019)examined the effect of microwave CP treatment on the inactivation of PPO in potato. The study identified the optimal conditions for PPO inactivation, achieving the highest rate (49.5%) at a CP generation power of 900 W and a treatment duration of 40 min [110]. The direct exposure of water to NTP results in the generation of Plasma-Activated Water (PAW) process, with relevant antimicrobial properties that persist for long periods of time [185].