亲水胶体对不同蛋白质消化吸收特性的影响研究

Protein’s digestibility is one of the important factors commonly used to evaluate protein and related products quality. The combined techniques of in vitro and in vivo digestion models were employed to investigate the influence of three different soluble dietary fibers (xanthan gum, guar gum and locust bean gum) viscosities on whey protein isolate (WPI) and soybean protein isolate (SPI)’s digestion and absorption. By adjusting the viscosity of the three different dietary fibers (DF) to be the same before subjecting them to digestion conditions, it was discovered that the viscosities became different following the exposure to the digestion conditions. This subsequently impacted differently on the digestibility of the protein in each DF system demonstrating the influence of DF rheological properties on protein digestion. DF with higher viscosity in the gastrointestinal tract recorded lower digestibility of the protein material in the system. In contrast, the protein digestibility under in vivo digestion models showed less difference between groups. For the in vitro digestion model, xanthan gum and guar gum in high viscosity system reduced the digestibility of SPI to 64.3% and 70.9% in the control group. In the animal experiment, 10% xanthan-gum group and 10% guar-gum group reduced the digestibility of SPI to 82.6% and 84.1% in the control group. The less variability in utilization among groups in the animal mode in comparison with the in vitro models could be attributed to the longer length of the animal small intestine, which could probably increase following long -term feeding. For example the length of small intestine were 110cm,130cm and 144cm that corresponds to control group, high-viscous guar gum group and high-viscous xanthan gum group, as a result the rats of high viscous groups could digest and absorb protein more sufficiently, due to the possible reduction of the inhibitory effect of protein digestion caused by the addition of dietary fibers.