Oxidative gelation of feruloylated arabinoxylan as affected by protein. Influence on protein enzymatic hydrolysis

The oxidative gelation of wheat water extractable arabinoxylan (WEAX) with or without protein (bovine serum albumin, BSA) was investigated by dynamic rheometry and diferulate formation analysis. The G′ moduli of the WEAX or WEAX–BSA gels were not strictly correlated to the diferulate formation as (i) maximal diferulate content coincided only to half G′ increase (ii) BSA strongly impaired G′ increase without any change in the diferulate accumulation. These features suggest that the covalent diferulate cross-linking could only partly explain the G′ increase. The WEAX gel was shown to protect the embedded BSA against pepsin proteolysis. The proteolysis of BSA can be reduced by 30% to 60%, depending on the WEAX–BSA ratio. This protective effect still occurred in thermally treated WEAX–BSA gel.