Understanding the role of Radix Paeoniae Alba polysaccharide for corn starch gel amelioration: Physicochemical, structural, and digestive properties

To ameliorate the limitations of corn starch (CS) processing, Radix Paeoniae Alba polysaccharide (RPAP) was used to modulate the physicochemical and digestive properties of CS. The main purpose of this paper is to investigate the effects of RPAP on the pasting, rheological, thermal, structural, and digestive properties of CS. The results show that the addition of RPAP could increase the peak viscosity and final viscosity of CS gel, and RPAP could increase the apparent viscosity, storage modulus, loss modulus, hardness, and strength of CS gel, implying that RPAP can effectively improve the pasting and viscoelasticity properties of CS. Moreover, RPAP could be bound to CS through non-covalent interaction, and RPAP could improve the relative crystallinity and thermal stability, whereas decreased the spin relaxation time (T2) of CS from 312.16 to 203.25 ms. The microstructure of CS-RPAP gels showed a honeycomb-like porous structure, and RPAP could increase the pore size and thickness of CS-RPAP gels. Furthermore, RPAP could inhibit the digestibility of CS, while increased the resistant starch (RS) content. The findings can provide important references for expanding the application of starch-based products in various fields including food industry, pharmaceuticals, textiles, papermaking, and biodegradable materials.