Physicochemical Properties and Storage Stability of Radix Cynanchi bungei Starch Gels: Pasting, Retrogradation, and Texture.
Abstract
Starch gels derived from various plant sources have a wide applications in multiple fields. Radix Cynanchi bungei (RCb), a traditional medicinal plant, has gained attention as a novel starch source, yet little is known about the characteristics of RCb starch gels and the factors affecting the gel stability and functionality. In this study, two cultivars of RCb starch (YW201501 and BW201001) were gelatinized into gels. The pasting, rheological, retrogradation, texture, and storage and freeze-thaw stability of RCb starch gels were investigated. YW201501 had a higher amylose content and more short branches (A and B1 chains), while BW201001 had larger granule sizes and more long branches (B2 and B3 chains). Gel properties for YW201501 exhibited lower pasting temperature and higher peak and final viscosity, whereas BW201001 showed lower breakdown and setback at low water content. Rheological analysis revealed pseudoplasticity of RCb starch gels, where YW201501 showed more pronounced shear-thinning behavior. With prolonged storage, the gels showed intensified retrogradation, increased hardness, decreased cohesiveness and transparency, and conversion of bound water to free water. YW201501 gels exhibited better freeze-thaw stability with lower syneresis, whereas BW201001 gels showed lower digestibility, characterized by a higher resistant starch and a lower digestion rate. Practical Application This study supports the innovative design and wide application of sustainable products involving Radix Cynanchi bungei starch gels, and ultimately promoting the development of healthy starchy foods.