Thiamin (vitamin B1) and thiamin phosphate esters in five cereal grains during maturation

► Developing grains of wheat, triticale, rye, oats, and barley. ► Content of thiamin and its phosphate esters in grains at different growth stages. ► During grain maturation, total thiamin content in cereals dry mass is nearly constant. ► Non-phosphorylated thiamin increased and thiamin diphosphate decreased continuously. ► Phosphorylated thiamin isomers convert into less highly or non-phosphorylated forms.