Inactivation of Yeast on Grapes by Plasma-Activated Water and Its Effects on Quality Attributes

Plasma-activated water (PAW) is a promising nonthermal technology in food preservation and food safety. The inactivation efficacy of PAW was investigated against Saccharomyces cerevisiae CICC 1374 inoculated on grape berries. PAW30 and PAW60 were obtained by activating water with plasma for 30 and 60 min, respectively. Grapes were directly treated with PAW, and a 0.38- to 0.53-log CFU/ml reduction of S. cerevisiae was achieved in a time-dependent manner (P < 0.05). The oxidation-reduction potential and pH values of PAW30 and PAW60 were also in a time-dependent manner (P < 0.05). Grape quality assessment demonstrated no significant change in surface color and total anthocyanin content after 30 min of PAW60 treatment (P > 0.05). Although grape quality was unaffected by PAW in this study, this technology should be optimized to enhance inactivation efficiency.