Effect of Non-Thermal Plasma-Activated Water on Fruit Decay and Quality in Postharvest Chinese Bayberries

Abstract

Recently, non-thermal plasma-activated water (PAW) became a relatively new concept developed in the food industry. The effects of PAW on fruit decay, microbial loads, and quality of postharvest Chinese bayberry were investigated. Chinese bayberries were treated by PAW for 0.5, 2, or 5 min and then stored at 3 °C for 8 days. Experimental results show that all PAW treatments could reduce fruit decay by around 50 % compared to control at the end of storage. There was no dose-effect relationship between PAW treatment time and fruit decay. Meanwhile, a 0.5-min PAW treatment could remarkably decrease microbial population on Chinese bayberries during storage, and the maximum reductions reached around 1.1 log CFU/g both for bacteria and fungi at the end day of storage. Scanning electron microscopy results reveal that PAW could significantly change the morphology of microbial cells on Chinese bayberries. Moreover, physicochemical properties analysis of PAW demonstrates that the microbial inactivation of PAW is mainly attributed to the combined action of high oxidation reduction potential and low pH. Additionally, PAW-treated fruits exhibited markedly higher firmness, color index of red grapes, and total soluble solids than the control did at the eighth day. These results indicate that PAW might be a promising strategy to control fruit decay and maintain quality of Chinese bayberry during postharvest storage.