Reaction catalyzed by beta-amylase (3.2.1.2)

		+		H2O	=			+
	(alpha-D-glucopyranosyl-(1-4))n-alpha-D-glucopyranose	+		H2O	=		(alpha-D-glucopyranosyl-(1-4))n-2-alpha-D-glucopyranose	+		alpha-D-glucopyranosyl-(1-4)-beta-D-glucopyranose