Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 9/1/2005
Publication Date: 9/17/2005
Citation: Niemira, B.A., Alvarez, I., Annous, B.A., Gutsol, A., Fridman, A. 2005. Antimicrobial efficacy of cold atmospheric pressure plasma applied to inoculated food surfaces. IFT-NPD Meeting, September 15-16, 2005, Wyndmoor, PA. Interpretive Summary:
Technical Abstract: Cold, atmospheric pressure plasma (CAPP) has previously been shown to effectively eliminate bacteria, including human pathogens, from inert surfaces. A series of experiments were conducted to evaluate CAPP efficacy on food products that represent important classes of surfaces for potential treatment: apples (hydrophobic, organic, smooth), cantaloupe (hydrophilic, organic, rough) and eggs (hydrophilic, mineral, smooth). The surfaces were spot-inoculated with either Listeria innocua ATCC 51742 (non-pathogenic surrogate for L. monocytogenes) or E. coli ATCC 25922 (surrogate for Salmonella). The inoculated products were treated with CAPP, using two plasma generation technologies: gliding arc discharge (GA) and dielectric barrier discharge (DBD). DBD treatments were 20kV@ 12kHz with varying time of exposure, GA treatments varied with voltage and exposure time. Populations of L. innocua on apples were reduced by 0.3 log10 cfu (115mA for 2 min.), 0.6 - 1.1 log10 (150mA for 2 or 4 min.) or 1.6 log10 (260mA for 2 min.). DBD (1 min.) reduced L. innocua by 2.0 log10. GA reduced E. coli 25922 on treated cantaloupe by 1.0 (260mA for 1 min.) or 1.3 logs (260mA for 3 min.). DBD (2 min.) reduced E. coli 25922 by 1.0 log10. GA reduced E. coli 25922 on treated eggs by 0.4 log10 (260mA for 1 min.) or 1.0 log10 (260mA for 2 min.). DBD reduced the surviving populations of E. coli 25922 by 1.0 log10 (0.25min) or 1.3 log10 (1 min.). The more aggressive treatments were associated with increases in surface temperature of the product (17-26C). Under optimized treatment conditions, the appearance of the foods was maintained. The results of these initial studies indicate that the CAPP tested herein have potential for adaptation to surface sanitization of food products.