Real-time in situ measurements of free radicals during Plasma sterilization

2016 Fiscal Year Final Research Report

• Project/Area Number: 26286071
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Plasma electronics
• Research Institution: Nagoya University
• Principal Investigator: Ishikawa Kenji 名古屋大学, 工学(系)研究科(研究院), 教授 (60417384)
• Co-Investigator(Renkei-kenkyūsha): OHTA Takayuki 名城大学, 理工学部, 准教授 (10379612) ; TANAKA Hiromasa 名古屋大学, 大学院工学研究科, 特任講師 (00508129)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: プラズマ滅菌 / 電子スピン共鳴

Outline of Final Research Achievements

The low-temperature plasma sterilization have advantages for applications. However, complexity of plasma processes arises from the involvement of a myriad of species including: electrons, ions, radicals, and photons. Such plasma components are needed to be measured and analyzed for fine-tuning the process. To determine the best practice for the sterilization, plasma diagnostics were conducted on clarifying the relationship between the control parameters and the plasma parameters.
Penicillium digitatum spores, which causes green mold on citrus, are inactivated by contribution of extracellular reactive oxygen species (ROS). The stable free radical as semiquinone in the spores decreases during oxygen atom irradiation observed using real time in situ electron spin resonance (ESR). The plasma electrical discharge induce metabolic modification. Also, intracellular metabolites induce the inactivation of spores. These understanding provides the development of plasma sources.

Free Research Field

プラズマエレクトロニクス