Dairy products play an important role in human nutrition, with milk occupying a fundamental place in the Tunisian diet. Given its metabolisable energy content, milk has a high concentration of basic nutrients such as high-quality proteins, carbohydrates, lipids and vitamins, with a high energy value, making it a complete and balanced food containing essential minerals. The dairy sector also plays a very important role and is essential to Tunisia's economy and society. Like all foodstuffs, dairy products can be a serious source of infection, which is why consumer protection must be ensured. To ensure the high quality of UHT milk and guarantee the satisfactory production of products such as yoghurt, butter, Raieb and UHT milk, physical, chemical and microbiological analyses are carried out systematically.