Effect of Cold Plasma and Plasma Activated Water on Polyphenols, Vitamins, and Volatile Compounds in Fresh‐Cut Carrots

This study aimed to evaluate content of bioactive compounds (polyphenols and vitamins B2 and B3 by HPLC‐MS/MS and spectrophotometric analysis, ascorbic acid by HPLC‐DAD and the volatile profile by HS‐SPME‐GC–MS) in fresh‐cut carrots treated with CP and PAW for 5‐10‐20‐30 min. The polyphenol content was affected mostly by PAW; the ascorbic acid content statistically increased by CP and PAW, especially after 10 min of treatment; nicotinamide decreased in both treatments, while nicotinic acid increased in CP‐treated samples. The volatile profile was also influenced by the application of CP and PAW: CP applied for 5 min slightly increased the abundance of volatile compounds whereas the PAW treatment completely changed the volatile profile. Finally, spectrophotometric analysis revealed the highest TPC value in CP‐treated carrots for 20 min and PAW‐treated for 5 min; the TFC value instead was higher in CP‐treated carrots for 5 min and with PAW for 20 min; antioxidant activity was higher in carrots treated with CP for 5 min and with PAW for 20 min. In conclusion, this study shows that both CP and PAW treatments contribute to altering the chemical composition of fresh‐cut carrots, with the PAW treatment having a greater impact on the content of some bioactive compounds, especially for polyphenolic compounds. In fact, a reduction of polyphenolic content of 29% and 26% was found in samples treated with CP for 10 and 30 min, respectively; while in PAW treated samples the reduction was around 70% regardless of the treatment time.