“…However, many of the ferulates remain in their original monomeric form ( Bunzel, 2001 ), and key characteristics of AX, particularly those related to enzymatic digestibility and microbial fermentation, are mediated not only by ferulate dimers’/higher oligomers’ crosslinking of cell wall polymers, but also by the abundance and structural complexity of their monomeric feruloylated side-chain substituents. For example, many arabinofuranosidases cannot cleave even the most simple feruloylated side-chain, feruloylated arabinose (FA; 5- O - trans -feruloyl- l -arabinofuranose; see Figure 1 ), from the xylan backbone ( Wood and McCrae, 1996 ; Luonteri et al, 1999 ; Rémond et al, 2008 ; Schendel et al, 2016a ). A study focused on the maize grain fraction resistant to mild acid pretreatment and subsequent enzymatic saccharification found that feruloylated oligosaccharides made up 39% of the enzyme-resistant oligosaccharides, and most of these feruloylated oligosaccharides contained either the complex, feruloylated trisaccharide side-chain FAXG (α- l -galactopyranosyl-(1 → 2)-β- d -xylopyranosyl-(1 → 2)-5- O - trans -feruloyl- l -arabinofuranose; see Figure 1 ) or the feruloylated disaccharide FAX (β- d -xylopyranosyl-(1 → 2)-5- O - trans -feruloyl- l -arabinofuranose; see Figure 1 ) side-chains ( Appeldoorn et al, 2013 ).…”