Structural characteristics of dietary fiber (Vigna radiata L. hull) and its inhibitory effect on phospholipid digestion as an additive in fish floss

The insoluble and soluble dietary fiber were enzymatically extracted from the by-product of Vigna radiata L. and their structures were characterized by scan electronic microscope, Fourier transform infrared spectroscopy, and X-ray diffraction. The distinctive surface and chemical structural features endow the dietary fiber good absorbing capacity and antioxidant acitivity. Afterwards, a popular snack, fish floss, was fortified with the proposed dietary fiber. The recently developed rapid evaporative ionization mass spectrometry was successfully applied to study the effect of dietary fiber on fish floss digestion in the term of phospholipid. The results showed that the hydrolysis rate of phospholipids increased as the degree of unsaturation of the fatty acyl chain increased, while the addition of soluble dietary fiber (SDF) and insoluble dietary fiber (IDF) effectively slowed down the digestion rate of phospholipids. This study can guide for comprehensive utilization of byproduct of Vigna radiata L. and designing novel weight control diets.