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The Cold Atmospheric pressure Plasma (CAP) technology is an emerging technology used for conditioning and microbiological decontamination of biomaterials including food. A novel tool for inactivation of juice background spoilage microorganisms, as well as high count of inoculated yeast while maintaining physicochemical properties in tomato juice - CAP technology was utilized in this study. Dry matter content and pH were not significantly influenced by CAP generated in GlidArc reactor. Small increase of lycopene, and slight loss of vitamin C content were observed.

The paper presents the results of an experiment on the effect of pre-sowing stimulation of seeds with atmospheric pressure plasma jet operating with dielectric barrier discharge (DBD plasma jet) on the process of germination of Thuringian Mallow (Lavatera thuringiaca L.). Five groups of seeds characterized by a different exposure times (1, 2, 5, 10 and 15 minutes) as well as untreated seeds-control were used. Pre-sowing plasma stimulation of seeds improved germination parameters such as: germination capacity and germination energy for all tested groups relative to control. The highest germination parameters were obtained for seeds stimulated with plasma for the exposure times of 2 and 5 min. The analysis of the contact surface angle indicated the decrease of its' mean values upon seed stimulation while no statistical effects were observed. Analysis of the SEM scans revealed the increase in seed pattern intensity which could be attributed to removing of the surface parts of cuticle possibly covered with wax upon short time-2 and 5 min plasma treatment. Such a phenomenon can act similarly to mechanical scarification of seeds. Longer exposure of seeds to plasma resulted in affecting the deeper zone of cuticle and damage or fracture of some parts of the cuticle. Lower germination parameters of seeds upon longer exposure times to plasma may indicate mechanical damage of the seeds.

In the technological processes requiring mild treatment, such as soft materials processing or medical applications, an important role is played by non-equilibrium plasma reactors with dielectric barrier discharge (DBD), that when generated in noble gases allows for the effective treatment of biological material at a low temperature. The aim of this study is to determine the operating parameters of an atmospheric pressure, radio-frequency DBD plasma jet reactor for the precise treatment of biological materials. The tested parameters were the shape of the discharge (its length and volume), current and voltage signals, as well as the power consumed by the reactor for various composition and flow rates of the working gas. To determine the applicability in medicine, the temperature, pH, concentrations of H2O2, NO2− and NO3− and Escherichia coli log reduction in the plasma treated liquids were determined. The obtained results show that for certain operating parameters, a narrow shape of plasma stream can generate significant amounts of H2O2, allowing for the mild decontamination of bacteria at a relatively low power of the system, safe for the treatment of biological materials. [ABSTRACT FROM AUTHOR]

This paper presents an experiment using a radio frequency atmospheric pressure plasma jet to generate cold plasma for pre-sowing stimulation of Wolska onion seeds. Impact of the He + N2 afterglow plasma on germination was investigated. Eight groups of seeds characterized by different exposure times (2, 5, 10, 15, 60, 120, 240, and 480 s) and distance from the electrodes (20 mm and 50 mm) were used. Pre-sowing plasma stimulation of the seeds improved the germination capacity and germination energy for all tested groups, relative to control. The impact of radio frequency plasma on the onion seed germination parameters was statistically significant. The highest germination parameters were obtained for seeds stimulated for 240 s at a distance of 50 mm. No significant differences in physical and morphological properties of onion seeds were found. [ABSTRACT FROM AUTHOR]

The gliding arc discharge plasma reactors are known as a source of non-equilibrium plasma at atmospheric pressure. In the present study, generation of dominant reactive oxygen and nitrogen species in gaseous and liquid phase in water by the compact gliding arc device (mini-GAD) and corresponding bactericidal effects were investigated. Water and phosphate buffer solutions were used as model liquids. Mini-GAD is a strong source of nitrogen oxides (up to 800 ppm NO and 200 ppm NO2) that result in high concentrations of nitrites and nitrates in water solutions. The highest bactericidal efficacy towards Escherichia coli was achieved for non-buffered water solution. [ABSTRACT FROM AUTHOR]

For some applications of plastic materials, such as polystyrene, an important role is played by the wettability of the material. One of the methods of modifying material properties such as water contact angle is using nonthermal plasma. In this study, a radio-frequency atmospheric-pressure plasma jet source has been applied to the surface modification of a high-impact polystyrene film. The measurements show a dependence between the change in the water contact angle and the operating parameters of a nonequilibrium plasma treatment, such as the composition of the working gas, the flow rate, the distance from the plasma zone, and the discharge power. [ABSTRACT FROM AUTHOR]

Wettability is an important feature in describing the physicochemical surface properties of material surfaces. It can be determined by measurements of the contact angle. A plasma jet reactor with dielectric barrier discharge (DBD) was used to modify the contact angle of selected polymeric materials. [ABSTRACT FROM AUTHOR]

The paper presents experimental results concerning pre‐sowing stimulation of Thuringian Mallow (Lavatera thuringiaca L.) seeds with non‐thermal plasma generated in GlidArc reactor (dry nitrogen, atmospheric pressure) and its effect on the germination process. Five groups of seeds characterized by different exposure times were used. The effect of cold plasma on seeds was analyzed by investigation of microscopic pictures of carbon coated seed surfaces registered by means of electron scanning microscope. Visible changes in the seed surface structure could enhance the formation of micro‐pores which may be involved in water absorption, thus facilitating faster seed germination. Pre‐sowing plasma stimulation of seeds improved germination parameters such as germination capacity and germination energy for all tested groups, relative to control. The highest germination parameters were obtained for seeds stimulated with plasma for the exposure times of 2 and 5 min. [ABSTRACT FROM AUTHOR]

The application of RF-powered atmospheric-pressure plasma jet (APPJ) for changing the surface properties of rubber-modified styrenic polymers on the example of high-impact polystyrene (HIPS) is investigated. We have utilized a 0-D chemical kinetic model to identify the dominant particle species generated by our device in experimental conditions. Ozone is found to be an important species in the plasma, and in higher concentrations, it can also contribute to oxidative degradation of the specimen. Basic properties of APPJ, such as electrical characteristics and outlet gas temperature measurement results, are presented. Influence of the plasma treatment on HIPS surface wettability is discussed. [ABSTRACT FROM AUTHOR]

Cold Atmospheric pressure Plasma (CAP) is a non-thermal method used in food processing. CAP generated with the use of nitrogen in a Glide-arc device for 300 to 600 s exhibited high potential for microbial decontamination and did not induce substantial changes in the physicochemical properties of NFC tomato juice. Samples exposed to cold atmospheric plasma had mostly an intact structure, as revealed by digital microscopy. The investigations indicate that CAP can be applied for biological and chemical waste-free decontamination of food and extension of its shelf life. [ABSTRACT FROM AUTHOR]