Effects of xylanase on starch isolation and functional properties of waxy wheat flour

Abstract

Waxy wheat starch is difficult to be extracted from waxy wheat flour (WWF) due to the weak gluten quality and the existence of arabinoxylan (AX). The objective of this study was to understand effects of xylanase on starch isolation and functional properties of WWF. WWF with addition of xylanase had a lower water retention capacity, shorter dough development time, and longer dough stability time when compared to the one without xylanase. Addition of xylanase to the WWF dough decreased its viscoelasticity and bound water, increased its extensibility and immobilized water, and transformed it from the elastic to the extensible texture. The xylanase hydrolysis of water-unextractable AX promoted quick formation of gluten and the release of starch granules during wet milling of WWF. Results suggested that WWF could be wet-milled without any challenge by adding xylanase. A role of AX in the dough and during wet milling of WWF was proposed and illustrated.