7. Vitamins

7.1 Presentation

Vitamins are essential nutrients with a functional role. They exist as such in foods, and unlike the other groups, they do not undergo significant changes in the TD. Because humans have lost the ability to synthesize them, while plants and microorganisms have retained it, vitamins are often found in plant foods. Lastly, in keeping with their role, vitamins have no protein or energy value, and must be present in the diet in low doses.

From a chemical point of view, vitamins have a wide variety of chemical formulas, but they are small molecules as opposed to food macromolecules with repetitive motifs (polyosides, proteins). The frequent presence of one or more heterocyclic rings in their structure is related to the difficulty of their biosynthesis....