ABSTRACT
Introduction Cereals contain a mixture of different protein classes. The earliest classification by Osborne (1907) separated the proteins into four main groups based on solubility: albumins (soluble in water), globulins (soluble in dilute salt solution), prolamins (soluble in aqueous ethanol), and glutelins (partially soluble in dilute acid and alkali and forming the residue after sequential extraction of the other groups). The Osborne classification has proved valuable for the development of cereal protein chemistry. It is difficult, however, to obtain a sharp separation of different protein groups based on solubility because different classes tend to overlap. As a result, recent techniques such as high-performance liquid chromatography (HPLC; discussed in Chapter 10) are able to give a sharper resolution of the fractions.
