Heat treatment of milk

Abstract

Heat treatment is the most widely used processing technology in the dairy sector to guarantee product safety and longer shelf-life. It includes treatments such as thermisation (57-68°C/30 min - 15 s), low-temperature-long-time (LTLT)pasteurisation (63°C/30-40 min), high-temperature-short-time (HTST)-pasteurisation (72-80°C/15-30 s), ultra-high temperature (UHT) treatment (135-150°C/10-1 s) combined with aseptic packaging, and in-container sterilisation. In recent years, extended shelf-life (ESL) processing either with a combined process bactofugation-plus-HTST-pasteurisation or microfiltration-plus-HTST-pasteurisation or with a one-step ultra-pasteurisation (120-140°C/10-1 s), and usually combined with very clean packaging technology, is increasingly applied in many countries. ESL processing intends to combine the advantages of HTST-pasteurisation, such as no cooking flavour and low protein denaturation, with the advantage of a longer shelf-life of UHT treated and aseptically packed milk. This publication provides an overview of the different heat treatments applied to milk for direct consumption or prior to further processing, and their verification procedures.