Defatted tigernut flour as a novel substitute for wheat flour: impact on physicochemical and rheological properties during frozen dough storage

Abstract

SummaryThis study analysed the impact of adding different amounts (5–25%) of defatted tigernut flour (DTF) to frozen wheat dough at different freezing periods. The chemical composition and freeze–thaw stability of the composite flour, as well as the physicochemical properties (e.g., textural, tensile, and rheological properties) of the dough after being frozen, were assessed. It was found that the addition of DTF enhanced the nutritional value of the dough and improved quality characteristics such as texture and tensile properties of the dough after it had been frozen and thawed. With increasing DTF, the content of dietary fibre (8.69–9.63%) and ash (0.54–1.05%) increased significantly, but the content of starch (58.56–54.96%) and protein (11.03–10.35%) decreased as compared to that of wheat flour alone. The thermal and freeze–thaw stability of composite flour was greatly improved with increasing amounts of DTF, and the retrogradation of the dough was delayed. DTF (5–15%) proportionately delayed deterioration of springiness and retarded hardening of the frozen dough. In addition, the extensibility of the frozen dough was significantly increased by adding 10–25% DTF. The results suggest that DTF has the potential to positively influence the quality of frozen wheat dough, while at the same time increasing the high‐value utilisation of tigernut.