Optimization and evaluation of venturi tube reactors for non-thermal milk pasteurization using CFD method

Abstract

© 2026 Taki et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. With growing demand for preserving food’s nutritional and sensory qualities, non-thermal pasteurization methods like hydrodynamic cavitation in Venturi tubes offer an effective alternative to heat-based techniques. This study optimizes a Venturi reactor for milk pasteurization using computational fluid dynamics (CFD) with the k-ε turbulence model and response surface method (RSM). By adjusting throat diameter (4.91mm), length (13.15mm), and convergence/divergence angles (19.2°/8.31°), the design maximized turbulent kinetic energy (TKE) (0.2438 m2/s2 peak, 0.0305 m2/s2 average) and minimized energy loss (viscous dissipation 2.69 W, pressure drop 3483 Pa). Experiments confirmed a 2.91 log-reduction in E. coli, with negligible impact on milk’s fat, protein, and lactose, ensuring safety and quality.