Non-Thermal Plasma Technology for Almond Disinfection

Roger Ruan, Professor
Paul Chen, Senior Research Associate
Shaobo Deng, Research Fellow
Xiangyang Lin, Research Fellow
Yuhong Li, Assistant Scientist
Hanwu Lei, Research Assistant
Chul Kyoon Mok, Visiting Professor

Funding Source

Almond Board of California

Objectives

1. Investigate the effectiveness and efficiency of using Non-Thermal Plasma (NTP) technology for almond disinfection;
2. Compare the different discharge reactors and determine and optimize the working conditions such as plasma parameters and treatment time; and
3. Study the quality changes in almonds after NTP treatment (e.g. peroxide value, free fatty acids) as a function of treatment conditions and storage time.

Need or Impact

Almonds are California’s largest tree nut crop in total dollar value and acreage. A salmonella outbreak occurred on May 21, 2004, sickened about 25 people, and prompted a nationwide recall of more than 13 million pounds of almonds. Finding a method to disinfect raw almonds is critical. Non-thermal plasma may be an excellent alternative.

Project Status

In progress. Initial experimental results show that NTP is very effective on almond disinfection. The most significant achievement of this research is that a set of NTP processing parameters has been established which permits 5-log reduction of E. coli and salmonella.