Non-Thermal Fresh Food Sanitation by Atmospheric Pressure Plasma

Date

2016-07-10

Journal Title

Journal ISSN

Volume Title

Publisher

46th International Conference on Environmental Systems

Abstract

The Non-Thermal Sanitation by Atmospheric Pressure Plasma (NTSAPP) system was developed for sanitizing fresh food on long-duration space missions. Plasmas are ionized gases generated by electrical discharges and composed of electrons, positive/negative ions, neutrons, and other neutral species. Plasma processes are known to be highly effective in promoting oxidation, enhancing molecular dissociation, and producing free radicals and other types of high energies. Non-thermal plasmas provide an effective way to generate extremely reactive species and initiate a variety of chemical reactions of use in surface sanitation of fresh fruit and vegetables. The system operates by passing a carrier gas through plasma jet reactors. The generated plasma then flows with the air through a rotating food sanitation chamber. After passing around the material to be sanitized the carrier gas flows through a scrubber to break down any harmful components prior to being returned to the environment. The system prototype was designed to meet the interface and safety requirements for ISS hardware, including EMI emissions requirements. The antimicrobial efficacy of the system prototype was tested with several process gases, food items, and microbes. Testing showed that performance with bottled gas mixtures was not significantly better than performance with lab air as the process gas, which has the benefit of operation without pressurized gas lines and with minimal consumables. Tests performed with samples of lettuce, tomato, and radish inoculated with E. coli and Salmonella showed that fifteen minutes of sanitizing resulted in a 3.7 log reduction of E. coli on lettuce and tomato, a 3.2 log reduction of E. coli on radish, a 3.6 log reduction of Salmonella on lettuce and tomato and a 3 log reduction of Salmonella on radish. Testing with trained sensory analysis panelists showed the process had no significant impact on taste, olfactory or appearance quality.

Description

United States
Orbital Technologies Corporation
204
ICES204: Bioregenerative Life Support
Vienna, Austria
The 46th International Conference on Environmental Systems was held in Vienna, Austria, USA on 10 July 2016 through 14 July 2016.
Ross W. Remiker, Orbital Technologies Corporation, USA
Robert C. Morrow, Orbital Technologies Corporation, USA
Robert J. Surdyk, Orbital Technologies Corporation, USA
Magesh Thiyagajaran, Glasram Technologies, USA

Keywords

Fresh Food, Sanitation, Plasma, Antimicrobial Efficacy, Long Term Mission

Citation