Chemical and rheological characterization of arabinoxylan isolates from rye bran.

Background: Rye arabinoxylans (AXs) might be used as baking improvers for gluten-free (GF) bread. However, their extraction process still needs to be improved. Objective and methods: The aim of this study was to simplify AX extraction of rye bran by varying temperature and pH and evaluate its chemical and rheological properties for application in GF bread. Results and conclusion: The results demonstrated that higher amounts of AX and impurities were extracted with the increasing pH and temperature. AX yield reached values up to 3.3 g AX/100 g bran. Highest ferulic acid (FA) content (117.27 ± 1.46 mg/100 g) was achieved at the mildest extraction conditions (30 °C and 0.17 M NaOH). A/X ratio of isolates ranged between 0.53 and 0.57 and the gluten content between 81.30 and 216.78 ppm. Rheological measurements revealed typical pseudoplastic behavior of isolates. AX extracted at 30 °C and 0.17 M NaOH showed a slightly higher initial viscosity in comparison with the other isolates but was still inferior to carboxylmethylcellulose (CMC) and hydroxypropyl methylcellulose (HPMC). [ABSTRACT FROM AUTHOR]