Effect of extrusion feeding moisture on dough, nutritional, and texture properties of noodles fortified with extruded buckwheat flour

Buckwheat flour was extruded with different feeding moistures (FMs). It evaluated changes of dough, nutritional, and textural quality of noodles fortified with extruded buckwheat flour (EBF). Results indicated that EBF had significantly lower viscosities and was more resistant to retrogradation than control. EBF (30% FM) fortification remarkably prolonged composite dough stability time and reduced attenuation degree. Noticeable enhancement was observed in cooked noodles nutritional quality when EBF (18%~30% FM) fortification was employed. Compared with control, EBF (30% FM) fortification resulted in significantly higher content of total phenolics, total flavonoids, rutin, and kaempferol, as well as antioxidant capacity of cooked noodles. Furthermore, highest hardness, cohesion, springiness, and chewiness of noodles was achieved when fortified with EBF (30% FM), while the cooking loss was not reduced in contrast to control. Fortification with buckwheat flour extruded properly would improve both nutritional and texture quality of staple noodles. Practical applications Recently, chronic diseases frequently occur in the world, and staple food prepared from only wheat could not cater for consumers' desire for health. Buckwheat contains abundant phenolics (especially flavonoids) that possess numerous bioactivities, such as antioxidant capacity. It is essential to investigate staple noodles based on wheat–buckwheat composite flour. Thermal processing could improve the bioactive phenolics level and antioxidant capacity of many cereal products (e.g., wheat, corn, and oat). Besides, it contributes to the desirable texture formation of staple foods by modifying the starch–gluten network, and could alter the processing property (e.g., flour viscosity). Therefore, it is worth considering the application of extrusion (a typical thermal processing technique) in staple industry.