Decontamination of peppermint distillate using spark plasma: microbiological and physicochemical evaluation.

Microbial contamination of herbal distillates is one of the crucial problems that the market is commonly facing. Spark plasma can be proposed as a potential emerging solution for the decontamination of liquids even with the sensitive aromatic compound like peppermint (Mentha piperita L.) distillate. However, its probable effects on the physicochemical properties of distillate is the main area of concern which will be discussed in the current paper. According to our results, spark plasma with an energy of 2 J/pulse is able to achieve a 4-log reduction in Pseudomonas aeruginosa counts after 4 min of treatment. Various assessments including pH analysis, color measurement, evaluation of essential oil content and composition are employed to determine the likely side effects of the method on the final product. The results show that the plasma processing does not make any sensible changes in the peppermint distillate acidity and color. According to the results, the peppermint essential oil content decreases only about 4% in the samples affected by the plasma, however, content of menthol as the main compound of peppermint distillate reduces about 17%.

Elimination of diazinon insecticide from cucumber surface by atmospheric pressure air-dielectric barrier discharge plasma.

The food industry is in a constant search for new technologies to improve the commercial sterilization process of agricultural commodities. Plasma treatment may offer a novel and efficient method for pesticide removal from agricultural product surfaces. To study the proposed technique of plasma food treatment, the degradation behavior of diazinon insecticide by air-dielectric barrier discharge (DBD) plasma was investigated. The authors studied the effect of different plasma powers and treatment times on pesticide concentration in liquid form and coated on the surface of cucumbers, where the diazinon residue was analyzed with mass spectroscopy gas chromatography. Our results suggest that atmospheric pressure air-DBD plasma is potentially effective for the degradation of diazinon insecticide, and mainly depends on related operating parameters, including plasma treatment time, discharge power, and pesticide concentrations. Based on the interaction between reactive oxygen species and electrons in the plasma with the diazinon molecule, two degradation pathway of diazinon during plasma treatment are proposed. It was also found that produced organophosphate pesticides are harmless and less hazardous compounds than diazinon.