99E-18

S. DENG¹, R. Ruan², G. Huang³, C. K. Mok⁴, and P. Chen¹. (1) Dept. of Biosystems and Agricultural Engineering, Univ. of Minnesota, 1390 Eckles Ave., Saint Paul, MN 55108-6005, (2) Dept. of Biosystems and Agricultural Engineering, Univ. of Minnesota, 1390 Eckles Ave., 206 Biosystems and Agricultural Engineering Bldg., Saint Paul, MN 55108-6005, (3) Almond Board of California, 1150 9th St., Ste. 1500, Modesto, CA 95354, (4) Dept. of Food and Bioengineering, Kyungwon Univ., San 65 Bokjeong-dong, Sujeong-gu, Seongnam, 461-701, South Korea

Almonds are California's largest tree nut crop in terms of total dollar value and acreage. Approximately 6,000 almond growers produce nearly 100 percent of the commercial domestic supply and more than 75 percent of worldwide production. Almonds have an image that is both healthful and indulgent, with a rich, subtle flavor that makes them suitable with both savory and sweet foods. Recently almonds have been reported as a source of several SE PT30 infections. Therefore, finding a proper method to disinfect almonds is critical. Non-thermal plasma may be a good alternative. The objectives of this study were to investigate the effectiveness and efficiency of using Non-Thermal Plasma (NTP) technology for almond disinfection, and study the quality changes in almonds after the NTP treatment. In this research, a dielectric barrier discharge non-thermal plasma reactor was developed. The system contained two electrodes covered by epoxy resin plates that served as the dielectric barrier material. 20-30kV high voltage power was applied to the electrodes. For each batch treatment, 15 grams of almonds in a single layer were placed in the discharge chamber. The results show that non-thermal plasma was capable of killing E. Coli, and Salmonella inoculated on the almond samples. Bacterial kill increased with increasing discharge voltage, frequency and treatment time, and more than 5-log reduction was achieved for both E. Coli, and Salmonella within 30 seconds of NTP treatment. These results suggest that non-thermal plasma is a good method to disinfect almonds with minimal damage to their quality. It has great potential to compete with the current disinfection methods.

Session 99E, Nonthermal Processing: General II
8:30 AM - 12:00 PM, Wednesday AM Room Hall I-2

2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana