감압 플라즈마를 이용한 Escherichia coli 살균

목철균¹^,^*, 송동명¹

Low-Pressure Plasma Inactivation of Escherichia coli

Chulkyoon Mok¹^,^*, Dong-Myung Song¹

¹경원대학교 식품생물공학과

¹Department of Food Science and Biotechnology, College of Engineering, Kyungwon University

^*Corresponding author: Chulkyoon Mok, Department of Food Science and Biotechnology, College of Engineering, Kyungwon University, San 65 Bokjeong-dong, Sujeong-gu, Seongnam-si, Gyeonggi-do, 461-701, Korea, Tel: +82-31-750-5403; Fax: +82-31-750-5273, E-mail: mokck@kyungwon.ac.kr

ⓒ Copyright 2010 Korean Society for Food Engineering. This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Received: Mar 25, 2010; Revised: Jun 21, 2010; Accepted: Jul 05, 2010

Published Online: Aug 31, 2010

Abatract

Low-pressure plasmas (LPPs) were generated with different gases such as air, oxygen and nitrogen, and their inactivation effects against Escherichia coli were compared in order to evaluate the potential as a non-thermal microbial disinfection technology. Homogeneous plasmas were generated under low pressure below 1 Torr at gas flow rate of 350 mL/min regardless the types of gases. Temperature increases by LPPs were not detrimental showing less than 10°C and 25°C increases after 5 and 10 min treatments, respectively. The smallest temperature increase was observed with air LPP, and followed by oxygen and nitrogen LPPs. More than 5 log reduction in E. coli was achieved by 5 min LPP treatment but the destruction effect was retarded afterward. The LPP inactivation was represented by a biphasic first order reaction kinetics. The highest inactivation rate constant was achieved in air LPP and followed by oxygen and nitrogen LPPs. The small D-values of the LPP also supported its potentialities as a non-thermal food surface disinfection technology in addition to the substantial microbial reduction of more than 5 logs.

Keywords: low-pressure plasma; air; oxygen; nitrogen; E. coli; inactivation; kinetics