(464d) Liquid-Phase Electrical Discharge Plasmas Rapidly Inactivate Pathogenic and Spoilage Microorganisms in Water

This work seeks to reduce food wastage caused by microbial spoilage through the development of an energy efficient and effective food sterilization technology applicable to the liquid foods manufacturing sector.

We have developed an energy efficient plasma technology that can rapidly achieve 5-log or greater reduction of food spoilage organisms in water. The technology, which creates plasma directly in a liquid, sterilizes microorganisms by combinations of chemical (hydrogen peroxide and oxidative oxygenated species), physical (shockwaves and UV light), and electrical effects.

Through the manipulation of plasma chemistry, we were able to reduce the treatment time for selected microorganisms from 30 min to ~ 50 sec while achieving greater than 5-log reduction, and have noted differences in optimal plasma chemistries for different organisms of interest. The extent of sterilization appears to be determined by the plasma reactor design, input power, plasma electrode material, and electrode polarity. The work also discusses the mechanism of sterilization and investigates the possibility of using the technology to treat fruit juices.