## 1 Introduction  
The sources of contamination along the entire value chain of fresh and fresh-cut products are numerous and diverse (raw materials, processing tools, surfaces in contact with food, lack of hygiene among employees). A contaminated product will most likely lead to a negative impact along the entire production chain. Therefore, the internal process hygiene is especially monitored, and not only traditional, commercial measures are taken into account; new, innovative techniques are also gaining more and more attention. Non-thermal plasmas (non-equilibrium plasmas) are plasmas in which the cooling of ions and uncharged particles is more effective than the transfer of energy from energetically excited electrons to the latter particles. This has the effect that the gaseous environment does not heat up, which is usually the case in thermal plasmas [1]. Non-thermal plasmas are now used in some areas of medicine and other industries. Their high antimicrobial potential in combination with a non-thermal application is very advantageous [2]. Biofouling, a problem caused by microbial biofilms, leads to high resource and economic losses, especially in the food industry. Causes for the formation of biofilms can be the microbiological contamination of processed products such as meat, fish, vegetables or fruit [3], but also abiotic materials such as processing surfaces due to increased corrosion, increased fluid friction resistance and heat flow [4]. Normally, the typical microbial life cycle begins with adhesion to solid surfaces, and through subsequent multiplication this leads to the formation of three-dimensional, multicellular aggregatescalled biofilms, which finally and protectively embed themselves in a self-generated extracellular matrix (ECM; [5; 6]). In particular, microorganisms such as _Candida albicans_, which can be responsible for product spoilage and food-related illnesses, preferentially form biofilms on abiotic materials such as stainless steel, aluminum, glass, polytetrafluoroethylene (PTFE) seals and polyamide (PA). These materials are typically found in food processing plants [7; 8; 9]. For example, _Candida_ spp. has often been isolated from conveyor belts in the food and beverage industry [10; 11]. Economic losses in the food and health sector and a more sensitive public awareness are bringing food safety to the fore. For this reason, uniform guidelines for good manufacturing practice (GMP) and the Hazard Analysis Critical Control Point (HACCP) for the food industry have been introduced within the European countries. Nevertheless, the European Food Safety Authority has identified 49,950 food-borne outbreaks in 2016, resulting in illness, 3869 hospitalizations and 20 deaths [12]. There are also various hygiic standards in food production worldwide, but 841 food-borne disease outbreaks have been reported in the United States (USA), for example, resulting in 14,481 illnesses, 827 hospitalizations and 20 deaths in 2017 [13]. Conventional methods (high-pressure cleaners, brushing, wiping), which are supposed to help reduce biofilms, do lead to a loss of biomass, but not efficiently and sustainably enough. If a reduced biofilm remains after mechanical cleaning, it will most likely grow back with increased resistance and resilience [14; 15]. Currently, the majority of sterilization and disinfection methods are based on wet chemical processes (e.g., peracetic acid, hydrogen peroxide, chlorine dioxide, chlorine, active oxygen, ammonium compounds, isopropanol, phosphoric acid, formic acid or nitric acid), which are not only highly effective but can also promote the development of new resistances [16]. Despite the integration of cleaning and disinfection cycles in numerous process chains for the removal of organic (proteins, lipids, carbohydrates) and inorganic (salts) contaminations, it remains a major challenge to develop new and uniform safety standards. Alternative, innovative techniques and concepts can help to overcome the existing economic, political and social barriers in the future.