The formation of hydroxyl radical and long-living chemical species (H ₂ O ₂ , O ₃ , NO 3 − and NO 2 − ) generated in the liquid phase of a water falling film dielectric barrier discharge in dependence on the gas atmosphere (air, nitrogen, oxygen, argon and helium) was studied. The chemical molecular probe dimethyl sulfoxide was employed for quantification of ˙ OH, and the influence of hydroxyl radical scavenging on formation of reactive oxygen and nitrogen species was investigated. In addition to liquid analysis, plasma diagnostics was applied to indicate possible reaction pathways of plasma–liquid interaction. The highest ˙ OH production rate of 1.19 × 10 ⁻⁵ mol l ⁻¹ s ⁻¹ was found when water was treated in oxygen, with a yield of 2.75 × 10 ⁻² molecules of ˙ OH per 100 eV. Formation of hydrogen peroxide in air, nitrogen and argon discharges is determined by recombination reaction of hydroxyl radicals, reaching the highest yield of about 0.7 g kWh ⁻¹ when distilled water was treated in argon discharge. Ozone formation was dominant in oxygen and air discharges. Strong acidification along with formation of reactive nitrogen species was detected in water treated in air and nitrogen discharges.

Rosemary (Rosmarinus officinalis L.) is a plant worldwide cultivated mainly for essential oils, extracts, and as a spice. Up-to-date results showed diversity in composition of the essential oils, which may influence their quality, biological activity, and thermal properties. Therefore, the aim of this study was to investigate the chemical composition, antimicrobial activity, and thermal properties of the rosemary essential oils originating from Serbia and Russia. Additionally, oils were added to the sunflower oils in order to investigate possible antioxidant activity during the frying. Investigation of the chemical profile marked α-pinene, eucalyptol, and camphor as the most abundant compounds in both oils. However, overall composition influenced in such manner that Russian oil showed significantly higher antimicrobial activity, while Serbian oil proved to be better antioxidant agent in case of frying of sunflower oil. This would significantly influence possible application of the oils, which could be used as an antioxidant agent for extension of the food shelf life, or antimicrobial agent for protection against different microbial strains.