Effects of heat treatment on liquid milk quality and safety: nutritional changes, hazardous substances and control strategies

Heat treatment is a critical process in liquid milk, effectively ensuring microbiological safety while inevitably inducing complex physicochemical alterations. Although extensive research has documented quality modifications during milk processing, there remains a critical knowledge gap regarding the effects of heat treatment on the major components and the formation of hazardous substances. Understanding the changes in major components during heat treatment, along with the sensitive detection and effective control of hazardous substances are crucial for enhancing the quality and safety of liquid milk and protecting consumer health. In this review, the induction mechanism of heat treatment on protein denaturation, lipid oxidation and hydrolysis, lactose isomerization, micronutrient loss, Maillard reaction (MR) and other physical and chemical reactions is comprehensively analyzed. Additionally, the detection of hazardous substances in liquid milk and various feasible control strategies are elaborated in detail, which provides valuable information and insights to guide production practices in dairy industry.