Baking bread and other pasta also entails losses of important ingredients as a result of water extraction. This is because during the baking process, water is extracted from the outer part of the crust in particular, due to the high temperatures in the oven and the long baking times – up to four hours. On the one hand, water-soluble vitamins are lost along with the reduction in liquid, and on the other hand, the proportion of heat-sensitive nutrients and vital substances (macro- and micronutrients) decreases. In the case of vitamins B1 and B6, losses of up to 20% occur in the total bread, but these can be much higher in the crust alone. Particularly long baking times favor and increase crust formation and the resulting losses of vital nutrients. In the case of “pumpernickel”, the long exposure to heat results in a relatively thick crust, which causes vitamin B1 and B2 losses of 75%. In our body, this can quickly cause a vital substance deficiency, with vitamin B6 deficiency causing further vitamin, mineral and trace element losses. If there is too little of the vitamin in the body, this lowers the vitamin C level in the blood, the zinc level in the plasma and the iron status. The deficiency can even cause calcium, copper and vitamin B12 absorption to be blocked. Niacin could be inhibited in its formation. The changes in the crust of the bread also include the formation of brown condensation products, which can attack the proteins (protein) in our body and decrease its biological value.