Plasma sterilization. Methods and mechanisms

Abstract

Utilizing a plasma to achieve sterilization is a possible alternative to conventional sterilization means as far as sterilization of heat-sensitive materials and innocuity of sterilizing agents are concerned. A major issue of plasma sterilization is the respective roles of ultraviolet (UV) photons and reactive species such as atomic and molecular radicals. At reduced gas pressure (£10 torr) and in mixtures containing oxygen, the UV photons dominate the inactivation process, with a significant contribution of oxygen atoms as an erosion agent. Actually, as erosion of the spore progresses, the number of UV photons successfully interacting with the genetic material increases. The different physicochemical processes at play during plasma sterilization are identified and analyzed, based on the specific characteristics of the spore survival curves.

Effect of low-pressure cold plasma on surface microflora of meat and quality attributes

“…UV radiation, charged particles and reactive species are responsible for plasma sterilization, because they can interact with the bacterial cells. Inactivation of microorganisms may be due to destruction by UV irradiation of the DNA of microorganism, erosion of the microorganism, atom by atom, through intrinsic photodesorption or etching (Moisan et al 2002). Mentioned antimicrobial agents are produced in dependence on the adjusted parameters like gas composition, flow rate, moisture, temperature and excitation properties as a consequence of physical and chemical processes inside cold plasma (Ehlbeck et al 2011).…”

Cold atmospheric plasma manipulation of proteins in food systems

“…It may be categorized as thermal or non-thermal plasma, depending on its density and electron temperature (Zhu et al, 2011). All types of plasma---including high, atmospheric, and low-pressure plasmas, have a broad spectrum of applications in different fields, such as textile (Huang et al, 2013;Malshe et al, 2013), electronics (He et al, 2013), life sciences (Pröfrock and Prange, 2012), packaging (Guillard et al, 2010;Pankaj et al, 2014a), dental applications (Hoffmann et al, 2013;Kim et al, 2014), sterilization (Lerouge et al, 2001;Moisan et al, 2002;Akitsu et al, 2005;Lee et al, 2006;De Geyter and Morent, 2012;Klämpfl et al, 2012;Kim et al, 2013;Ziuzina et al, 2013;Cui et al, 2016), plasma medicines (Weltmann et al, 2012;Laroussi, 2014), and food processing (Banu et al, 2012). Thanks to the special features of low-temperature (cold) atmospheric plasma technology---including cost-effectiveness, ability to achieve a moderate temperature in the vacuum-free systems, and flexibility in practice---many studies have recently been conducted on cold plasma applications (Oh et al, 2011).…”

Antibacterial Activity and Physical Properties of Edible Chitosan Films Exposed to Low-pressure Plasma

“…Therefore, non-thermal, green technologies are being looked for by the researchers. Cold plasma is known as one of this novel method and its effectiveness in sterilization process was confirmed (Moisan et al 2002). Some advantages of low-pressure plasma such as the large treatable area, even distribution in vacuum chamber, uniformly treatment and low temperature of process are especially beneficial in meat industry.…”