Effect of extraction conditions and oxidative cross-linking on the chemical structure and microbial fermentability of arabinoxylans

Abstract

The aim of this thesis project was to obtain corn bran AX of varying structure by using different extraction conditions, oxidatively cross-link them, and determine the microbial fermentability of both the non-cross-linked and cross-linked samples. To reach this goal the following objectives were defined: *Determine the influence of NaOH concentration used for AX extraction on structural characteristics of extracted AX. *Determine the influence of a post extraction procedure, ball milling, on the structural characteristics of extracted AX. *Cross-link differently extracted AX by using laccase and oxygen. *Determine the effects of ferulate cross-linking on fermentability in an in vitro fermentation experiment and analyze fermentation end products (pH, gas volume, and SCFAs). *Determine the release/formation of phenolic metabolites by gut microorganisms as well as the percentage of original FA being metabolized by gut microbiota.