Influence And Mechanism Of Purple Sweet Potato Powder On Baking Performance Of Wheat Dough

Low-gluten wheat flour (LWF) and high-gluten wheat flour (HWF) were substituted by purple sweet potato powder (PSPP) at different ratios, respectively. The rheological and thermal properties were measured by farinograph, texture analyzer and differential scanning calotimetry (DSC). The results were as follows.(1) The addition of PSPP increased water absorption and softness of LWF and HWF, and extended dough development time and stability time. It was found that there was a strong positive correlation between farinograph parameters and addition amount of PSPP (Pearson’s r>0.978,P<0.01). Overall, dough stability was improved, but mixing performance was reduced.(2) There was a significant trend of increase for the hardness, adhesiveness, gumminess. chewiness and resilience of blended dough (P＜0.01), as the addition of PSPP increased.(3) PSPP reduced extensibility of blended dough and increased resistance to extension and R/E ratio, but extension area presented no obvious change rule. As a whole, the tensile properties of dough reduced and the strength increased after the additon of PSPP.(4) To, Tc, Tp and ΔHgel of blended flour showed an increasing trend with the increase of PSPP content from0%to30%. PSPP was easier to gelatinize than LWF and HWF. The addition of PSPP increased the difficulty of flour gelatinization. The assessment results of PSPP cakes suggested that the color and smell of cakes became better with the increase of PSPP addition, while expanding degree and mouthfeel declined. Furthermore, the increase of PSPP addition resulted in a grudual decrease of water content and specific volume, and an increase of the hardness and adhesiveness of cake. The corresponding texture parameters between cakes and dough had a good correlation. The correlation coefficients of hardness and adhesiveness were0.956,0.961, respectively (P＜0.01).