Structure of heteroxylans from vitreous and floury endosperms of maize grain and impact on the enzymatic degradation

Hetemxylans (HX) from vitreous and floury parts of maize endosperm were isolated. Structural analysis showed a xylan backbone with few unsubstituted xylose residues (<9%) demonstrating the high content in side chains in both fractions. HX from floury endosperm contained more arabinose and galactose than vitreous HX. The mono-substitution rate was 15% higher in the vitreous endosperm HX. Similar amounts of uronic acids were present in both fractions (similar to 7% DM). Galactose in the floury endosperm HX was present exclusively in terminal position. A xylanase preparation solubilized more material from floury (40.5%) than from vitreous endosperm cell walls (15%). This could be a consequence of the structural differences between the two fractions and/or of the impact of structure on the interaction abilities of these fractions with other cell wall polysaccharides. Our study advances the understanding of cell wall polysaccharides in maize endosperm and their role in enzymatic susceptibility of maize grain.

Automated summary

Hetemxylans (HX) were isolated from vitreous and floury parts of maize endosperm, with structural analysis revealing differences in side chain content between the two fractions. Xylanase was more effective at solubilizing material from floury endosperm cell walls compared to vitreous endosperm, suggesting varying enzymatic susceptibility based on structural differences between the fractions.