Influence of sand rice (Agriophyllum squarrosum) flour substitution on the physicochemical properties, bioactive activities, and in vitro digestibility of wheat bread

Sand rice (Agriophyllum squarrosum), as the seed of an annual spermaphyte, is generally concerned for its highly valuable nutrients. This study aimed to evaluate the effects of sand rice (SR) supplementation on the physicochemical properties, bioactive activities, and in vitro digestibility of wheat flour bread. Results showed that the addition of SR could significantly increase the total phenolic, flavonoid content, and antioxidant activity. Moreover, the SR-added bread had lower pasting viscosity and enthalpy of gelatinisation. In vitro starch digestion assay showed a higher slow digestion starch content and performed a lower digestibility rate in SR bread, while, in terms of 20% or higher addition levels, bread quality was negatively affected by SR regarding aspect ratio, specific volume, colour profiles, texture properties, and sensory evaluation. Overall, these results indicated that sand rice flour could be a fine replacement for wheat flour in bread formulations to increase the product's nutritional values and functional properties.