Arabinoxylan from Canna edulis Ker by-product and its enzymatic activities

Arabinoxylan (AX) was extracted and purified from Canna edulis Ker by-product. Through column chromatography, AX was further separated, leading to the isolation of two single compounds, namely, AXI and AXII. Moreover, the structures of AXI and AXII were characterized by GC, GC-MS and NMR. The result indicated that arabinose and glucuronic acid occurred at 1,4-linked xylose units as backbone at positions 3 and 2 in both AXI and AXII with varying ratios, respectively. Furthermore, the effects of AX on enzymatic digestibility of β-lactoglobulin and tributyrin hydrolysis by lipase were evaluated. The results showed that AX had obvious inhibition effects on pepsin and lipase activities, and decreased β-lactoglobulin digestibility and tributyrin hydrolysis as well. It indicates that C. edulis AX could be used as a functional food ingredient.