Do you know the differences between pasteurized milk and UHT milk? Both pasteurization and upgrading are sterilization treatments that increase milk’s shelf life. In addition, they destroy pathogenic microorganisms that can inhabit them and cause harm to humans.
Both methods consist of heating the milk for a certain period, cooling it, and packaging it. However, they show differences in heating times and organoleptic and nutritional changes.
In any case, these sterilization methods are not only used in the dairy industry. They are common in the brewing and manufacturing of many canned food, such as packaged sausages.
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How is pasteurized milk different from UHT milk?
Pasteurization
It results in fresh milk. It is a process by which milk is heated to a temperature between 55 and 75 ºC for 17 seconds. This process helps to eliminate pathogenic bacteria, maintaining the quality and properties of the product.
It allows, therefore, to respect a good part of its natural flora. However, this flora can alter the milk in a short time; For this reason, it is advisable to keep the product cold even if the container is not opened.
UHT milk
This is a more aggressive heat treatment. On the one hand, we have Uperized milk that is heated by injection with steam and then quickly cooled. On the other hand, there is UHT milk, which is subjected to temperatures of 138ºC for a few seconds.
It has been speculated that this type of treatment could produce waste products that are harmful to health. However, its innocuousness has been demonstrated. This is stated in an article published in the “European Journal of Clinical Nutrition” magazine.
This thermal process is a continuous flow and direct contact, which produces a minimum alteration of the product and allows it to be kept in perfect condition, even at room temperature. However, it must be consumed within a maximum period of 3 days once it has been opened.
Said treatment makes it possible to destroy the pathogenic organisms and sporulated forms. In any case, it is a relatively recent sterilization method. This is because, technologically, the industry ran into two problems: first, how to heat and cool milk quickly; and second, finding a sterile container for its conservation. The first problem was solved by applying steam and pressure variations, and the second with the invention of the tetra Brik.
Influence on nutritional properties
During pasteurization, there are practically no changes. DurPhotosensitivetamins, such as vitamin A or riboflavin, may be lost.
H during storage; however, things change in the case of UHT milk. As it is a more aggressive treatment from a thermal point of view, there is a loss of vitamins. The levels of ascorbic acid and vitamins B1 and B12 are reduced.
In addition, during prolonged storage, other vitamins, such as A and B6, may be lost. Proteins and amino acids will remain unchanged in both thermal processes.
These sterilization processes have allowed milk to reach homes with excellent safety and quality. It improves the conservation of the product and reduces its microbiological risk. However, the influence of UHT milk consumption on intestinal microflora has been studied in recent years. However, according to an article published in the journal “Nutrients,” no significant effects have been found, and no effective results were found.
Despite not reaching evidence A, the conclusions are that consuming this milk modifies the flora and increases inflammation. Therefore, it is recommended to prioritize the consumption of fresh milk over that of UHT milk.
UHT and pasteurized milk are two good foods
Both processes increase the milk’s shelf life and improve its hygienic safety. However, they have several differences:
- Pasteurized milk must be kept cold at all times. However, UHT milk can remain at room temperature until the container is opened.
- Pasteurized milk expires four days from its packaging, while UHT milk lasts months.
- Pasteurized milk presents organoleptic characteristics that are more similar to raw milk in terms of smell, flavor, and color. It has been subjected to a lower temperature than UHT milk.