2002 Annual Report
Research
Non-Thermal Discharge Plasma System for Liquid Pasteurization and Sterilization
Roger Ruan, Professor
Paul Chen, Senior Research Associate
Hongbin Ma, Post-Doctoral Associate
Xiangyang Lin, Research Fellow
Shaobo Deng, Research Fellow
Blanca Martinez, Scientist
Funding Source
SOTA Tec Funds
Objective
The objectives of the research are to (1) investigate the effectiveness
of the non-thermal plasma process on selected pathogenic microorganisms;
(2) study the effect of gas introduction, pH, temperature, and discharge
energy input on the killing of the microorganisms; and (3) evaluate the
energy consumption characteristics of the process. The project will also
involve extensive system development.
Project Description
Thermal processes have been traditionally used for pasteurization and
sterilization of spoilage and pathogenic microorganisms in foods. The
major disadvantage of these thermal processes is that the heat damages
the sensory quality and nutritional values of food products. In this project,
we will develop non-thermal plasma (NTP) reactors for non-thermal pasteurization
of liquid foods. Highly reactive NTP species including energetic electrons,
atoms, and free radicals are generated through electrical discharge at
ambient temperatures and kill microorganisms through rapid and vigorous
plasma-induced reactions. We will evaluate the feasibility of this new
technology and the effects of key variables on the effectiveness of the
process.
Results
New types of reactors have been developed and tested with water and liquid foods. Five logs reduction in bacteria were achieved. A patent has been filed to protect the invention.