ABSTRACT
World production of isolated starch, in the form of grains and products made from them, is of the order of 20 million tonnes. Amylopectin differs from amylose in having many more branches, and the branching enzyme is relatively more involved. It has been clear for a long time that there are a number of branching enzymes, which broadly accounts for the differences between different species in the extent of branching in their amylose and amylopectin. Starch has a number of applications, and a substantial proportion of it is used in non-food ways, and these applications can depend crititically on the relative levels of amylose and amylopectin. The enzymes that degrade starch are some of the most commercially important in biotechnology both as crude isolates and in vivo in the various brewing processes based on cereals. Classical biochemistry was almost entirely concerned with enzymes acting on substrates in solution in which enzymes attack lumps like starch grains.
