Rye grain is refined into a flour. Rye flour is high in gliadin but low in glutenin. It therefore has a lower gluten content than wheat flour. It also contains a higher proportion of soluble fiber. Alkylresorcinols are phenolic lipids present in high amounts in the bran layer (e.g. pericarp, testa and aleurone layers) of wheat and rye (0.1–0.3% of dry weight). Rye bread, including pumpernickel, is made using rye flour and is a widely eaten food in Northern and Eastern Europe. Rye is also used to make crisp bread.