Determination of the Effect of Low and Atmospheric-Pressure Cold Plasma Treatments and Pressure Conditions on Piperine and Volatile Oil of Black Pepper Seed (<i>Piper nigrum</i> L.)

This study aimed to assess the impact of atmospheric and low-pressure cold plasma treatments on the volatile oil and piperine content of black pepper. Raw black pepper was dehydrated and subjected to cold plasma treatment using an atmospheric gliding arc plasma discharge (760 mmHg, 250 V) and low-pressure cold plasma discharge (0.165 mmHg, 300 W). Hydrodistillation was used to extract volatile oils, and the constituents of the isolated volatile oils were examined utilizing gas chromatography–mass spectrometry and gas chromatography–flame ionization detection. Pepper oleoresin was extracted by solvent extraction, and the piperine content in the extracted oleoresin was estimated using the ultraviolet spectrophotometric method. There was no statistically significant difference (P > 0.05) between the volatile oil content and piperine contents in oleoresins of the atmospheric and the low-pressure cold plasma-treated sample. The relative concentrations of the main monoterpenes were lower, and the caryophyllene concentration was higher in low-pressure cold plasma-treated samples.