29G-14 |
Novel atmospheric pressure, room temperature plasma approach for an efficient disinfection of inorganic and organic polymer surfaces involved in food processing technologies |
F. S. DENES1, S. Manolache2, A. C. L. Wong3, Y. Wang2, H. Jiang2, and B. Dong2. (1) Dept. of Biological Systems Engineering, Univ. of Wisconsin, Madison, 460 Henry Mall, Madison, WI 53706, (2) Center for Plasma-Aided Manufacturing, Univ. of Wisconsin, Madison, 1410 Engineering Drive #101, Madison, WI 53706, (3) Food Research Institute, Univ. of Wisconsin, Madison, Dept. of Food Microbiology & Toxicology, 1925 Willow Dr., Madison, WI 53706 The active species of non-equilibrium discharges have energy levels, which are comparable with the energies of common chemical bonds and as a result, the structure of materials exposed to cold-plasma can be altered in a controlled manner regardless of their chemical nature. The Array Electrode Reactor (AER), atmospheric-pressure plasma technique opens up novel ways for the development of low cost, efficient, and in-line disinfection technologies for surfaces of processing equipment, such as cutting blades, conveyor-belt systems, log feeders, etc., that are in contact with ready-to-eat (RTE) meat and poultry products during processing. The objectives of this research, is to develop plasma-aided technologies that will allow to reduce significantly pathogen and toxins-based contamination levels and biofilm formation during RTE meet preparation, and an efficient sterilization of packaging materials. Surface sterilization processes were carried out using AER plasma technologies. This original plasma tool is provided with a specially designed multi-cylinder/wire configuration electrode array system, which allows the processing of gases or gas mixtures at atmospheric pressure and surfaces exposed to the fluxes of plasma species (low temperature atmospheric plasma jet) under batch- or continuous-flow-system operation mode. It has been demonstrated that artificially developed biofilms from 5-strain cocktail of Listeria monocytogenes on 2.5 cm2, 304 (# 4 finish) stainless steel coupons and exposed to AER-air-plasma environments reduced the biofilm population by 78 and 91% after 30 sec and 1 min treatment, respectively. AER-oxygen-plasma conditions exhibited even higher disinfection efficiency. The biofilm population was reduced in this case by 95 and 92%, after 30 sec and 1 min plasma-exposure. Spores could also be inactivated by this approach. The number of Bacillus stearothermophilus spores, air-dried on stainless steel substrates was reduced by 72 and 93% after a two minutes air- and oxygen-plasma treatment, respectively. These results suggest that atmospheric-plasma techniques could play a very important role in the future in the development of efficient disifection technologies with application in food–processing industries.
Session 29G, Food Microbiology: General
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