Soluble dietary fiber from Canna edulis ker by-product and its enzymatic and antioxidant activities.

摘要

Soluble dietary fiber (SDF) was prepared from Canna edulis Ker by-product by physical-enzymatic method and its structure was characterized using GC, FT-IR, 1H-NMR, and solid 13C-NMR spectroscopy. The results exhibit that SDF is mainly composed of polysaccharides with minor phenolic compounds. Moreover, influences of SDF on protease hydrolysis of beta-lactoglobulin ( beta-lg) and lipase hydrolysis of tributyrin (TBG) were determined. The results indicate that SDF promotes N release of beta-lg by pepsin, despite it inhibiting the enzymatic activity of pepsin. Inversely, tryptic hydrolysis of beta-lg is inhibited by the addition of SDF, which has no obvious effect on tryptic activity. SDF also inhibits lipase hydrolysis of TBG and the inhibition rate increases with increasing SDF concentration. Furthermore, antioxidant activities of SDF were evaluated by six different modes, and the relationship between concentration and activity was discussed. The results indicated different activities determined by different methods, suggesting that antioxidant mechanisms of SDF are complicated