A Comparison of the Sustainability of Thermal, High Pressure, and UV Milk Pasteurization Technologies Using Multi-criteria Decision-Making

Conventionally used thermal milk pasteurization methods such as high-temperature short-term (HTST) and low-temperature long-term (LTLT) treatment are associated with flavour and nutritional defects. This has given rise to an increased interest in non-thermal pasteurization techniques such as high-pressure processing (HPP) and ultraviolet (UV) processing. However, there is limited research comparing their sustainability. Therefore, this study compared the sustainability of LTLT, HTST, HPP, and UV pasteurization technologies using PROMETHEE II multi-criteria decision-making framework, utilizing data collected from previous studies, with the pasteurization unit as the defined system boundary. Based on an overall net outranking flows, UV processing was determined to be the most sustainable method. The study also used uni-criterion preference flow analysis to evaluate each criterion separately, and it showed that UV processing performed better than the other techniques in terms of reducing water consumption, auxiliary equipment requirement, and impact on flavour. Sensitivity analysis was also carried out to determine the criterion that wielded the most significant influence on the final decision. The results highlighted that percentage change in fatty acids is the most sensitive criterion, further highlighting its critical role in the selection of an optimal pasteurization method. The results of the study emphasize the growing acceptance of non-thermal technologies, with UV processing emerging as the most suitable way for pasteurizing milk, due to its superior performance in terms of a number of sustainability criteria. It provides useful information for the dairy industry's decision-making process.