Eco-Friendly Non-Thermal Inactivation of Escherichia coli in Wheat Flour Using Cold Plasma Technology
Date
2025-05-12
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
ORCID
0000-0002-0538-4029
Type
Thesis
Degree Level
Masters
Abstract
This study investigated the application of atmospheric cold plasma (ACP) for reducing Escherichia coli in wheat flour and explored its effects on various quality attributes. Initially, response surface models (RSM) were developed to optimize ACP treatment for E. coli inactivation using three different gases: nitrogen, air, and argon. The analysis identified sample mass and treatment time as critical factors, with nitrogen gas proving the most effective, achieving a maximum reduction of 5.55 log CFU/g under optimized conditions. Subsequently, the study assessed the impact of ACP treatment on microbial dynamics, dough ripening, rheological properties, and sensory quality of wheat flour. Using optimized RSM parameters, ACP treatment resulted in a 3.10 log CFU/g reduction in E. coli without inhibiting the growth of lactic acid bacteria, suggesting a synergistic effect for pathogen control. Fungal growth was significantly reduced, corroborating ACP's efficacy in microbial inactivation. Dough fermentation times remained unaffected, while texture profile analysis (TPA) indicated that adjustments in moisture content could modulate changes in dough texture. Sensory evaluations revealed no significant consumer-perceived differences in pancakes made from treated versus untreated wheat flour, implying only subtle alterations in dough properties. This research highlights ACP as a promising non-thermal technology for enhancing food safety in wheat flour while maintaining its baking functionality. Future work should focus on scaling up the technology through the development of a dielectric barrier discharge (DBD) system for indirect treatment under vacuum conditions, aiming for efficient, homogeneous processing of large flour quantities, as preliminary designs and tests have indicated potential improvements in treatment efficacy and uniformity.
Description
Keywords
Atmospheric cold plasma (ACP), Escherichia coli, Wheat flour, Response surface models (RSM), Nitrogen gas, Microbial inactivation, Food safety, Non-thermal inactivation
Citation
Degree
Master of Science (M.Sc.)
Department
Chemical and Biological Engineering
Program
Biological Engineering