Alpha and beta amylase enzymes found in malted barley (also found in your mouth and small intestine) are used to break down the starch present in the kernel into maltose and maltotriose, which are chains of two or three linear glucose molecules, respectively.
However, most grains are made up of the carbohydrates called «amylose» and «amylopectin», the former is a linear chain of glucosemolecules (similar to Maltodextrin) and the latter is an amylose backbone with amylose branches.