Changes in the structure and gelling properties of maize fiber arabinoxylans after their pilot scale extraction and spray-drying

The effects of pilot scale extraction and spray-drying on structure (molecular weight, hydrodynamic radius, branching and phenolic compounds) and gelation capacity of maize fiber arabinoxylans (AX) were assessed. A control extract was obtained at laboratory scale and freeze-dried (ctrl-AX). The AX obtained at pilot level were either freeze-dried (AX (-)) or spray-dried (AX (+)). Total carbohydrates, molecular weight and sugar linkages were not affected by the scale extraction. Ctrl-AX formed more viscous solutions (3.5 times), had higher ester-linked ferulic acid (e-FA) (1.5 times) and smaller hydrodynamic radius (1.3 times) compared to those extracts obtained at the pilot scale. All AX gels showed elastic behavior in creep-recovery tests, but as indicated by their measured complex viscosity (eta* = 32-40 Pa s) and maximum creep compliance (Jcmax = 0.4-0.06 1/Pa) extracts obtained from pilot scale were weaker compared to ctrl-AX = (eta* = 216 Pa s, Jcmax = 0.01 1/Pa). A better understanding on the relationships between the AX structure and its gelling properties was obtained; likewise, useful aspects to consider for scaling up AX extraction from maize fiber are presented in this manuscript. (C) 2016 Elsevier Ltd. All rights reserved.