The effect of cold plasma treatment on the phenolic and flavonoid content and antioxidant activity of whole buckwheat grain and flour.

Atmospheric cold plasma (ACP) is a novel non-thermal technology which increases shelf-life of food. The aim of this research to evaluate the effects of ACP treatment on antioxidant activity (AOA), total phenol content (TPC), total flavonoid content (TFC) and rutin and quercetin levels of Common buckwheat (Fagopyrum esculentum Moench) flour (BF) and grain (BG). Whole buckwheat grains and flour were subjected to a dielectric barrier discharge plasma reactor for 5 and 10 min at 50 and 60 kV. Results demonstrated the significant impact of ACP treatment on phenolics, flavonoids, especially rutin, and antioxidant activity. BF sample treated at 50 kV-10 min (S2), and BG sample treated at 60 kV-5 min (S3) showed the most AOA (92.25 ± 0.03, 89.69 ± 0.04% by DPPH and, 48.09 ± 0.05, 42.88 ± 0.03 mmol Fe/mg DW by FRAP), TPC (83.99 ± 0.07, 80.47 ± 0.03 mg GAE/g DW), TFC (96.60 ± 0.03, 91.53 ± 0.07 mg RE/g DW), and rutin (3.6 ± 0.06, 2.7 ± 0.02 mg/kg) levels, respectively. Results indicated that optimum ACP treatment can increase TPC, TFC, and AOA of buckwheat.