Effects of sweet potato starch on the physicochemical properties and edible qualities of instant fresh rice noodles.

Instant fresh rice noodles (IFRNs) on the market suffer from issues such as undesirable gel hardness and poor extensibility after high-temperature sterilization and rehydration, significantly compromising their mechanical properties and overall edibility. This research aimed to improve the quality of IFRNs by incorporating sweet potato starch (SPS) into rice flour. The physiochemical properties and multi-scale structural properties of the IFRNs with SPS were then characterized by differential scanning calorimetry, texture profile analysis, wide-angle X-ray diffraction, Fourier transform infrared spectroscopy, small-angle X-ray scattering, and scanning electron microscopy. Adding SPS significantly decreased the enthalpy changes, and long- and short-range ordered structures, while increasing the crystalline layer thickness and forming a more regular and ordered network structure in IFRNs. Furthermore, the addition of 30 % SPS greatly improved the IFRN tensile properties and edibility. Compared to the control IFRNs, the tensile strain and gel springiness were increased from 63.93 % and 0.86 to 170.38 % and 0.92, respectively. The tensile stress, gel hardness, and chewing hardness were decreased from 174.47 Pa, 1283.52 g, and 273.27 g to 113.03 Pa, 871.42 g, and 90.30 g, respectively. Therefore, the addition of SPS is a simple, convenient, and low-cost method for producing high-quality IFRNs.