To further depict the interaction mechanism of wheat arabinoxylan (AX) and gluten proteins upon thermal processing, AX was enzymatically tailored with defined substitution patterns and the impact on the heat-induced polymerization behavior of gluten was comparatively studied. The results showed that tailormade AX promoted the formation of glutenin-glutenin and glutenin-gliadin macrocrosslinks upon heating, with the optimal effect detected for AX depleted of Araf of disubstituted Xylp. The tailormade AX, especially AX depleted of monosubstituted Xylp, facilitated the polymerization ability of α-gliadin into glutenin compared with untailored AX. The unfolding process of gluten was partially impeded by AX upon heating, while the tailormade AX promoted the unfolding process. AX could bury Trp and Tyr upon polymerization of glutenin and gliadin and induced the change of the disulfide bridge conformation to a less-stable state, while the effect was alleviated with tailormade AX. The enhanced polymerization with tailormade AX strengthened the gluten network and induced more heterogeneously distributed large protein aggregates.
Keywords: AX; enzymatically tailored; gluten; heat-induced polymerization.