Enzymic Hydrolysis and Industrial Importance of Barley β‐Glucans and Wheat Flour Pentosans

Abstract

AbstractMixed linkage β‐glucane and pentosanes (mainly arabinoxylanes) are the major endosperm cell‐wall polysaccharides of barely and wheat respectively. These polysaccharides, although minor components of the whole grain, significantly affect the industrial utilization of these cereals. The modification of barley corns during malting requires the dissolution of the β‐glucane in the cell‐wall of the starch endosperm. High β‐glucane concentration in wort and beer effect the rate of filtration and can also lead to precipitate or gel formation in the final product. In a similar manner, pentosane is thought to cause filtration problems with wheat starch hydrolysates by increasing viscosity and by producing gelatinous precipitate which blocks filters. Ironically, it is this same viscosity building and water binding capacity which is considered to render pentosanes of considerable value in dough development and bread storage (anti‐staling functions). In the current paper, some aspects of the beneficial and detrimental effects of pentosanes and β‐glucane in the industrial utilization of wheat and barley are discussed. More specifically, enzymic methods for the preparation, analysis and identification of these polysaccharides and for the removal of their functional properties, are described in detail.