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. 2022 Jun 28;32(6):768-775.
doi: 10.4014/jmb.2203.03056. Epub 2022 Apr 15.

Optimization of Atmospheric Cold Plasma Treatment with Different Gases for Reduction of Escherichia coli in Wheat Flour

Jeongmin Lee  1 , Seul-Ki Park  1 , Darren Korber  2 , Oon-Doo Baik  1
Affiliations

Optimization of Atmospheric Cold Plasma Treatment with Different Gases for Reduction of Escherichia coli in Wheat Flour

Jeongmin Lee et al. J Microbiol Biotechnol. .

Abstract

In this study we aimed to derive the response surface models for Escherichia coli reduction in wheat flour using atmospheric cold plasma (ACP) with three types of gas. The jet-type atmospheric cold plasma wand system was used with a 30 W power supply, and three gases (argon, air, and nitrogen) were applied as the treatment gas. The operating parameters for process optimization considered were wheat flour mass (g), treatment time (min), and gas flow rate (L/min). The wheat flour samples were artificially contaminated with E. coli at a concentration of 9.25 ± 0.74 log CFU/g. ACP treatments with argon, air, and nitrogen resulted in 2.66, 4.21, and 5.55 log CFU/g reduction of E. coli, respectively, in wheat flour under optimized conditions. The optimized conditions to reduce E. coli were 0.5 g of the flour mass, 15 min of treatment time, and 0.20 L/min of nitrogen gas flow rate, and the predicted highest reduction level from modeling was 5.63 log CFU/g.

Keywords: Escherichia coli; Non-thermal treatment; atmospheric cold plasma; response surface method; wheat flour.

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Conflict of interest statement

Conflict of Interest

The authors have no financial conflicts of interest to declare.

Figures

Fig. 1
Fig. 1. Schematic diagram of the atmospheric cold plasma (ACP) treatment system with carrier gas.
A, plasma generator; B, gas nozzle; C, plasma jet; D, wheat flour sample; E, vortex mixer; F, customized sample treatment container; G, gas flow meter; H, gas inlet; I, power supply; J, gas bombe.
Fig. 2
Fig. 2. Response surface (3D) plots of the reduction values of Escherichia coli (log CFU/g) with three gases.
Each row is arranged with three types of gas used. A-C, Argon; D-F, Air; G-I, Nitrogen. The figure order by row; the effect of time × mass, flow rate × mass, and flow rate × time.
See this image and copyright information in PMC

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