NON-STARCHY POLYSACCHARIDES OF CEREAL GRAINS: VII. PRELIMINARY STUDY OF PENTOSAN ENZYMOLYSIS

Abstract

Preliminary investigation, using rye arabo-xylan as substrate, indicates that degradation with the enzymes of ungerminated barley involves attack on internal linkages in the molecule, giving rapid diminution in viscosity with slow development of free reducing groups, though this action—when prolonged—leads to the production of a series of pento-oligosaccharides including xylobiose. Simultaneously, there is rapid initial production of free arabinose, whilst free xylose is present in the products of prolonged action. Raw barley also contains an enzyme or enzymes causing solubilization of initially insoluble pentosan hemicelluloses. Transarabinosylation must be considered as one possible factor among others in solubility changes, though the evidence suggests that transarabinosylation may be more significant in wheat than in barley.