Influence of Cold Plasma Processing on the Stability of Phenolic Compounds of Araça-Boi (Eugenia stipitata) Juice

Abstract

Knowledge of the chemical changes caused during plasma treatment is essential to enhance food quality. In this work, the influence of two cold plasma technologies, dielectric barrier discharge plasma and glow discharge plasma, on the phenolic profile of araça-boi (Eugenia stipitata) juice was investigated and assessed by gas chromatography coupled to mass spectrometry. Eight phenolic compounds were identified in araça-boi, with cinnamic acid being the major phenolic compound of the fruit juice, followed by protocatechuic acid. The effects of excitation frequency and plasma flow rate were evaluated because these are the main operating conditions that can be set for plasma treatments. The phenolic profile slightly changed due to the reaction of the phenolics with the reactive plasma species produced during the treatment, with the highest increase in phenolic content observed in the dielectric barrier discharge plasma operating at 1000 Hz. Both plasma systems increased the bioavailability of phenolic compounds in the juice, which could be increased by up to 201% using the dielectric barrier discharge plasma. Plasma application increased the concentration of cinnamic, hydrocinnamic, benzoic, and p-coumaric acids. Overall, plasma treatment improved the bioavailability of the phenolic compounds and resulted in slight changes to the phenolic profile of araça-boi juice. Thus, the technology showed a positive effect on araça-boi juice. This work advanced our further understanding of the changes induced by cold plasma treatment on phenolic compounds and characterization of araça-boi (Eugenia stipatata).