The inactivation effects of yeast by spray and bubbler cold plasma

Abstract

Abstract Liquid foods such as juice are typically prone to contamination by spoilage yeasts. In this study, different cold plasma reactors (spray and bubble) were designed and tested for the removal of osmotolerant yeasts in apple juice. Factors influencing the deactivation of osmotolerant yeasts were studied by altering the reactor discharge voltage and working gas flow rate. The results indicate that both reactor discharge voltage and working gas flow rate significantly affect yeast deactivation efficiency. Compared with the bubble reactor, the spray reactor can increase the deactivation efficiency by about 10%, and the working gas flow rate has a more considerable impact on the deactivation efficiency of the bubble reactor. Both reactors can deactivate microorganisms by damaging their cell membranes. Furthermore, these two plasma applications did not affect the apple juice’s physical and chemical characteristics or its volatile compound’s significantly.