Thiamine and riboflavin are lost during both wet and dry methods of cooking. Vitamin C is readily destroyed by heat, the losses being less with deep-frying. Starchy foods are digested better after cooking. The biological value of proteins is generally increased by wet methods of cooking. Protein value of pulses increases when subjected to heat because of the destruction of trypsin inhibitors.
Fats deteriorate in nutritive value when subjected to prolonged heat combined with exposure to air.
Changes in fat quality are less with baking, in bread, puddings etc. Fermentation and sprouting can compensate for the above losses by bringing about increase in vitamin content of foods. Fermentation makes cereals and pulses more suitable for children in the post-weaning period. It improves digestibility of the food. During fermentation, the microorganisms secrete enzymes that facilitate the partial degradation of starch, protein, etc.