O UHT milk (Ultra High Temperature), also known as Long Life, is obtained by the Ultra High Temperature Pasteurization process. Milk is homogenized and submitted to a temperature of 130 to 150º, between 2 and 4 seconds, and immediately cooled to a temperature below 32ºC.
The thermal shock that the milk goes through was named Pasteurization, this process allows to eliminate the bacteria, thus the properties of milk are preserved without the need for refrigeration, hence the name "long life".
The packaging, in which UHT milk is confined for sale, is aseptic (inhibits the development of microorganisms). The moment the package is opened, the milk is already subject to contamination and therefore it is recommended that, after opening, the product is stored in the refrigerator and consumed within 3 days. The unopened package has a shelf life of 180 days.
The composition of long-life milk can vary in relation to the percentage of fat, let's see:
UHT Whole Milk: consists of 3.0% total fat, 2.0% saturated fat, 3.0% protein and 4.5% carbohydrate. Each 100g of product contains about 58 Kcal.
UHT semi-skimmed milk: has less fat: 2.0% total fat, 1.2% saturated fat, 3.1% protein and 4.6% carbohydrate. Each 100g provides about 50 Kcal.
UHT skimmed milk: the fat content cannot exceed 0.5%, so the product has a maximum of 0.5% of total fat, 0% of saturated fat, 3% of protein and 4.5% of carbohydrates.
As the name implies, in the process of obtaining skimmed milk, the cream (higher concentration of fat) is removed, each 100g provides only about 30 kcal.
*These data are related to the requirements of the Nutritional Value of milk and are inspected by the Sanitary Surveillance.
By Líria Alves
Graduated in Chemistry
Source: Brazil School - https://brasilescola.uol.com.br/curiosidades/composicao-leite-uht.htm
