What is UHT milk?

Ultra Heat Treatment Milk is a generally used technique in the processing of milk by milk
production facilities to ensure the food safety of the milk. In the UHT process, milk is heated to
extremely high temperatures for a short period of time while retaining its nutritional value in
order to eradicate any undesirable and harmful bacteria that may be present in raw milk. Milk is
heated by ultra-high temperature of 135-145°C and kept for 2-4 sec. for sterilization.
The higher temperatures that are used in this process help to ensure that milk is not only safe to
consume, but also shelf-stable when packaged. This allows the finished product to be kept in its
sealed and unopened packaging at ambient room temp. for extended periods of time. The UHT
process is a kind of pasteurization process, although it's carried out at higher temperatures as
compared to pasteurized milk.
Pasteurization is a low-temperature sterilization method invented in 1865 by French named
Pasteur. Pasteurization is that the process of heating milk for a predetermined time at a
predetermined temperature to destroy pathogens. The thermal destruction process is logarithmic,
and bacteria are killed at a rate that’s proportional to the number of bacteria present.
Pasteurization improves a product’s safety and extends its time period by killing pathogenic and
rotting organisms. Pasteurization kills most disease-causing organisms and prevents fermentation
in milk, beer, and other liquids by sterilizing them partially or completely. The Pasteurization
process heats milk to 72 0 C for 15 seconds, inactivating or killing organisms that grow rapidly in
milk.
UHT milk has a shelf life of many months and doesn’t need to be refrigerated until the package
is opened. The shelf life of UHT milk is not limited by growth of microorganisms but instead by
physical, chemical and enzymatic changes within the milk, like browning reactions, cream
separation, and sediment or gel formation. “Fresh milk” is usually used by consumers to describe
milk that is distributed under chilled conditions.
Nutrition competition
The nutritive value of UHT milk and fresh milk are the same when it comes to the main nutrients
in milk, similar as protein, calcium and Vitamin D. Some heat-sensitive nutrients, like vitamin C,
may be reduced during UHT processing. The immunologically active protein in milk is
denatured by high temperatures, and UHT milk has a greater nutritional loss of protein than
pasteurised milk. Second, after being sterilised at a high temperature, the soluble calcium in milk
will change into insoluble calcium that is difficult for the body to absorb. Nutrients in milk will
gradually be lost during storage. Therefore, pasteurised milk is a better option from a nutritional
point of view.