Plasma Sterilization of Polyethylene Terephthalate Bottles by Pulsed Corona Discharge at Atmospheric Pressure

Abstract

A pulsed power supply was used to generate a corona discharge on a polyethylene terephthalate bottle, to conduct plasma sterilization at atmospheric pressure. Before generating such a discharge, minute quantities of water were attached to the inner surface of the bottle and to the surface of a high voltage (HV) electrode inserted into the bottle. Next, highvoltage pulses of electricity were discharged between electrodes for 6.0s, while rotating the bottle. The resulting spore log reduction values of Bacillus subtilis and Aspergillus niger on the inner surface of the bottle were 5.5 and 6 or higher, respectively, and those on the HV electrode surface were each 6 or higher for both strains. The presence of the by-products gaseous ozone, hydrogen peroxide, and nitric ions resulting from the electrical discharge was confirmed.

Cold Physical Plasmas in the Field of Hygiene—Relevance, Significance, and Future Applications

“…Depending on the type of microorganism, plasmas achieved this condition within a few seconds to 30 min of treatment time . Surfaces in the foods manufacturing process including packaging materials or bottles can also be decontaminated with plasma. A high voltage dielectric barrier discharge (DBD) reduced biofilm‐resident Pseudomonas aeruginosa by 5.4 log within 60 s and completely within 300 s of exposure time .…”

Killing of adherent oral microbes by a non-thermal atmospheric plasma jet

“…Furthermore, UV irradiation, ions and electrons are emitted in the plasma discharges, which also interact with biological material or tissues (Laroussi & Leipold, 2004;Vleugels et al, 2005). In medicine, plasmas are used to sterilize surgical instruments and consumables (Masaoka, 2007). Another important medical application is argon-plasma coagulation (Manner, 2008).…”

Rapid eradication of bacterial phytopathogens by atmospheric pressure glow discharge generated in contact with a flowing liquid cathode

“…To the best of our knowledge, no dc‐APGD‐based plasma‐reaction system working in a flow‐through mode has been proposed until now for eradication of bacterial phytopathogens. Former applications of APPs sources mainly involved eradication of human pathogens or microbial contaminants of food present on surfaces of Petri and quartz plates, seeds, plastic bottles, animal skin, or model materials imitating, for example, nails or hoofs (Butscher et al, ; Ermolaeva et al, ; Gabriel et al, ; Lu et al, ; Masaoka, ; Xiong et al, ). According to our best knowledge, Lu et al () were the first to use an APP source, in this case DBD, to inactivate with nearly 100% efficacy a plant pathogenic fungus Cladosporium fulvum .…”

“…Such measures could involve atmospheric pressure plasma (APP) sources of antimicrobial properties due to generated electrons, ions, heat, UV light, electric field, and various active species, and radicals (Ikawa, Kitano, & Hamaguchi, ). APP can be produced with the aid of various sources, including dielectric barrier discharges (DBDs) (Butscher, Van Loon, Waskow, Rudolf von Rohr, & Schuppler, ; Lu, Liu, Song, Zhou, & Niu, ; Miao & Yun, ; Shen et al, ; Tiede, Hirschberg, Viöl, & Emmert, ; Xiong, Roe, Grammer, & Graves, ; Yong et al, ), corona discharges (Kuwahara, Kuroki, Yoshida, Saeki, & Okubo, ; Masaoka, ), radio frequency discharges and plasmas (Akitsu, Ohkawa, Tsuji, Kimura, & Kogoma, ; Laroussi et al, ; Li et al, ; Matan, Puangjinda, Phothisuwan, & Nisoa, ; Ohkawa et al, ), microwave discharges (Gabriel et al, ; Park et al, ), and glow discharges (GD) (Dzimitrowicz et al, ,; Ikawa et al, ). To the best of our knowledge, DBD (Lu et al, ; Tiede et al, ; Xiong et al, ) and radio frequency discharges and plasmas (Laroussi et al, ; Ohkawa et al, ) have been implemented for microbiological and biomedical applications so far.…”