Exploring the Synergistic Effects of Ultrasound, Ultraviolet, And Ozone Treatments On Milk Quality

Abstract

Objective: This study aims to evaluate the synergistic effects of three prominent non-thermal techniques; Ultrasound (US), Ultraviolet (UV) and Ozone (O3) on milk quality. The objective is to determine whether this hurdle-based approach can enhance the functional, structural, and nutritional properties of milk, without compromising the nutritional integrity, thereby offering a clean-label alternative to the conventional thermal techniques. Methodology: Raw milk was subjected to combined US-UV-O3 treatments under optimized conditions. Microbial load was performed using total plate count method. The functional changes were analyzed by measuring curdling time at room temperature. Advanced analytical techniques such as Confocal Laser Scanning Microscopy (CLSM) for microstructural imaging, Differential Scanning Calorimetry (DSC), and Fourier Transform Infrared Spectroscopy (FTIR), were performed to assess structural and molecular alterations. Result & Conclusion: The synergistic (US-UV-O3) treatment led to a significant decrease in microbial load up to 4.2 log₁₀ CFU/mL log cycle, signifying a strong combined efficacy compared to individual methods. Interestingly, the curdling time enhanced from 6 to 12 hours. CLSM revealed the fragmented and evenly dispersed structure of milk lipids, with a more compact casein structures, which demonstrates improved emulsion stability under the synergistic treatment. DSC analysis demonstrated a 2.5 °C increase in onset denaturation temperature, indicating improved thermal stability of milk proteins. FTIR analysis suggested no major structural disruption in the characteristic amide and lipid bands, elucidating that the hurdle technology maintained the chemical integrity of milk components. This technology thus offers a clean-label, energy efficient and much better alternative to conventional pasteurization.