In this process, the food is deprived of the water available to it in order to stabilize the product, depriving the harmful organism of a base necessary for it and thus extending the shelf life. In addition, the dehydration makes heat necessary, which consequently leads to a change in quality and often also to a change in shape and structure. Heat-sensitive nutrients and vital substances (macro- and micronutrients) are particularly affected, so that the content of vitamins C, A and beta-carotene must be viewed very critically. Vitamins B2, B6 and folic acid are also among the heat-sensitive vitamins. Excessively high temperatures greatly minimize their content in food. Vitamin C losses, for example, are between 10 and 50% and vitamin A losses between10 and 20%. Water extraction results in the loss of essential, water-soluble vitamins in particular, such as the B vitamins, folic acid, biotin and niacin.
