Advanced Non-Thermal Processing: Combined Cold Plasma and Pulsed Electric Field for E. coli Inactivation in Milk

By:
Kimia Taki, Bahram Hosseinzadeh Samani, Shirin Ghatrehsamani
Date:
2026

This original research developed and optimized a combined atmospheric cold plasma–pulsed electric field (ACP-PEF) system as a non-thermal alternative to conventional milk pasteurization. Using response surface methodology, the study optimized electric field strength, exposure time, argon-to-air ratio, and plasma jet nozzle angle to maximize microbial inactivation while preserving milk quality. Under optimal conditions (10 kV/cm, 35 s, argon-to-air ratio 0, nozzle angle 53.87°), the system achieved a 4.656-log reduction (99.9978%) of Escherichia coli. Compared with thermal pasteurization, ACP-PEF caused substantially smaller reductions in pH, fat, protein, lactose, solids-not-fat, and fat-free portion, and produced no visually detectable color change (ΔE = 0.81). The findings demonstrate that ACP-PEF offers an energy-efficient, scalable, and nutritionally protective approach for producing microbiologically safe milk without heat-induced quality degradation.