## 3 Results and Discussion
Further investigations are necessary and will provide a better insight into the chemical and biochemical processes underlying the antimicrobial effects observed and assumed in the present work. The high quality and safety of food is achieved by the high hygiic standard in its production. The importance of production hygiene and quality assurance increases with the level of microbiological requirements to be met. In the food industry in particular, inadequate hygiene leads to health risks for consumers due to food-borne diseases and leads to economic risks due to high production losses. The high nutrient content and relatively high pH value (pH 5.5 to 7) of some fruit and vegetable varieties can promote the growth of pathogens [52]. Bacterial and fungal contamination of food itself or of the production environment, as well as interrupted freezing and cooling chains, can be a cause of food-borne diseases, as well as production and quality losses. _L. monocytogenes_, _Salmonella_ sp., _Clostridium_ sp., _E. coli_, _Staphylococcus aureus_ and _Aspergillus_ sp. are human pathogens typically found on and in food. Phyto-pathogens include many molds (e.g., _Fusarium_ sp. ), Oomycetes, _Xanthomonas_ sp., _Erwinia_ sp. and _Pseudomonas_ sp. These can have a negative effect on product quality. Regular cleaning and disinfection cycles of production facilities and rooms to reduce the microbiological load can mean high costs, lower productivity, possibly heavily contaminated waste water and material damage for the food producer. Therefore, there is a great need for innovative cleaning concepts in the food industry, which supplement or replace existing plants with resource-saving, versatile and efficient technologies. Against this background, the use of the plasma-based PTW/PPA decontamination process investigated in this study seems promising. The functionalization of air and water to fungicidal and antimicrobial agents by non-thermal plasma leads to a fast acting decontamination agent without leaving toxic residues on food or production surfaces and can be applied in adjustable, product-specific process windows at room temperature. These advantages, coupled with an on-demand application and easy integration into existing cleaning processes, make cold plasmas particularly attractive for decontamination in food processing [53; 54]. As mentioned above, microorganisms such as _C. albicans_ can contribute to biofilm formation on surfaces. The essential step of biofilm formation is the transition from a reversible attachment of the cells on surfaces to irreversible adhesion [55; 56]. Therefore, fungicidal and antimicrobial cleaning and inactivation can make a positive contribution to biofilm prevention. In addition to the observed antagonistic, additive and synergistic inactivation effects, another important point for the combined treatment of _C. albicans_ and the previously published bacteria and endospores was observed [44]. In disinfection and sterilization processes, deviations from the exponential inactivation kinetics are often found. In the semi-logarithmic representation, these deviations can show concave curves up to the so-called tailing instead of the expected linear relationship. In the case of tailing, the inactivation strives towards a lower limit value, which thus represents a process limit that cannot be overcome even by a massive extension of the process times. The reasons for the non-exponential inactivation kinetics can be manifold and have been discussed in the literature for a long time with no agreement having been reached up to now. [PERSON] (1977) provides a good review of this topic [57]. Under certain conditions, tailing can also occur in the two plasma processes described here. Therefore, it is of crucial importance for an economic use of the process to take measures to reduce or eliminate tailing completely. In the combination of the two processes, it was shown in our work that this is possible under certain parameters.