Application of electromagnetic fields to mitigate fouling in ultra-high temperature processing of calcium-fortified milk containing monoglyceride: industrial efficacy and mechanistic insights

Fouling of heat exchanger surfaces during ultra-high temperature (UHT) processing of calcium-fortified milk is a significant industrial challenge. This study investigated continuous in-line electromagnetic field (EMF) treatment (105–110 kHz, 0.8 T) to mitigate fouling in calcium-fortified milk containing monoglyceride at industrial scale (20 m³/h) during UHT processing (140 °C, 4 s). EMF pretreatment reduced fouling deposition rate by 96.2% (from 1.06 to 0.04 g/m2·h, p < 0.001), virtually eliminating macroscopic fouling. Mechanistic studies revealed that EMF reduced ionic calcium by 12% (from 2.18 to 1.92 mmol/L) and restored casein micelle zeta potential from −14.1 mV to −19.5 mV, comparable to non-fortified controls. Particle size analysis showed that monoglyceride converted particle size distribution from bimodal to monomodal, eliminating large fat aggregates (>10 μm). Six-month storage stability confirmed sustained fouling inhibition. To our knowledge, this is the first demonstration of continuous in-line EMF pretreatment for fouling mitigation in calcium-fortified UHT milk at industrial scale, providing a clean-label, energy-efficient (1.2 W) physical alternative to conventional chemical additives.Industrial relevance This physical approach offers a clean-label, industrially scalable solution with negligible energy consumption (1.2 W) for producing stable calcium-fortified UHT dairy products while dramatically reducing operational costs associated with fouling-related downtime and cleaning.