Non-Thermal Milk Decontamination by Ionic Modulation: A Deionization-Based Alternative to Pasteurization

The dairy industry requires effective non-thermal processing strategies capable of ensuring microbial safety while preserving the nutritional and bioactive quality of milk. This study describes a novel milk decontamination approach based on selective ionic removal by dialysis, resulting in a controlled reduction in ionic strength. Milk deionization significantly reduced the microbial load in raw bovine milk to levels comparable to those achieved by conventional thermal pasteurization, while largely preserving its physicochemical composition. Ionic depletion enhanced the antimicrobial effectiveness of endogenous milk components; this effect was abolished when native salt concentrations were maintained, highlighting the key role of ionic modulation in microbial control. Major milk constituents, including proteins, fat, and solids-not-fat, were not substantially affected by deionization, whereas low-molecular-weight solutes such as lactose and urea were partially removed. Deionized milk also exhibited improved stability during refrigerated storage, as evidenced by delayed acidification compared with raw and pasteurized milk. Overall, these results demonstrate that milk deionization represents a feasible proof-of-concept non-thermal alternative to pasteurization based on ionic modulation, with potential applications in dairy processing and human milk preservation, where maintenance of bioactive components is particularly desirable.