Role of charge exchange collision on generation of active species for cold plasma food processing

Abstract

Charge exchange collision (CXC) is well known in solar and space plasmas. In this work, we present how the CXC between N2+ and N2 can be exploited to overcome major challenges in cold plasma food processing (CPFP). CPFP is an emerging application of glow discharge plasmas for physicochemical modifications to achieve shelf-life enhancement, preservation, surface activation for germination, antimicrobial treatment, surface cleaning, etc. The commercial application of CPFP is in its infancy and it faces two major challenges. The first challenge is the difficulty in generating the desired active species for the required modification, and the second is the very high processing cost. In this paper, with the help of numerical modeling for nitrogen discharge, we show that the CXC between N2+ and N2 can be utilized to generate active species selectively, enhance energy efficiency, and possibly eliminate the processing gas cost. The modeling is followed by experimental demonstration and validation of the proposed concept. This work may lead to a new direction of transdisciplinary research towards the commercial application of CPFP.