Evaluation of the Ochratoxin A Reduction and Physicochemical Properties of Green Coffee Beans Following Atmospheric Nonthermal Plasma and Plasma-Activated Water Treatments

Abstract

Nonthermal plasma (NTP) is a novel nonthermal technology with many potential applications in the food industry because of its promising effects on food decontamination, including mycotoxin decontamination. In this study, atmospheric NTP and plasma-activated water (PAW) were used to evaluate ochratoxin A (OTA) reduction and the quality of green coffee beans. Artificially contaminated green coffee beans were subjected to atmospheric NTP, PAW, atmospheric NTP-PAW, and PAW-atmospheric NTP treatments for 2 min, and OTA was then analyzed using liquid chromatography with tandem mass spectrometry before and after each treatment. NTP-based treatments significantly reduced OTA concentration in green coffee beans by 37.66%–51.80%. The maximum reduction efficiency was found in PAW-atmospheric NTP treatment. Furthermore, no negative effects were observed in terms of color, caffeine content, total phenolic content, total flavonoid content, and DPPH scavenging activity, except for atmospheric NTP treatment, which exhibited distinct color changes. In addition, a minimal decrease in the aroma of green coffee beans was observed following atmospheric NTP and PAW treatments, whereas a minimal increase was observed when both treatments were combined. NTP-based treatments provide new approaches for mitigating mycotoxin in the food industry as well as important implications for the use of atmospheric NTP and PAW in the coffee industry.