Various technologies exist to produce dairy products. They are either physical (thermal, mechanical etc), chemical (acidification) or biological (enzymatical, fermentation.). Several technologies can be used in succession but the impact, in particular in relation to the nutritional value of the proteins, is nevertheless relatively minor. For example, the proteins are able to undergo modifications of their spatial structure (denaturation) with generally positive effects on their digestibility and their allergenicity. These treatments could also lead to interactions between proteins and other components in milk such as vitamins, lipids, carbohydrates* etc.
* The Maillard reaction between proteins and carbohydrates (after heating) leads to browning of the milk, releasing of odour molecules, but also to a decrease of the availability of certain amino acids (lysine in particular).