RVA analysis of mixtures of wheat flour and potato, sweet potato, yam, and cassava starches

Rapid visco analysis (RVA) was performed to study the pasting properties of mixtures of wheat flour and tuber starches, i.e., potato starch (PS), sweet potato starch (SPS), yam starch (YS), and cassava starch (CS), at 10-50% starch in the mixtures. Lower phosphorus and higher amylose contents were observed in CS, followed by YS, SPS; and PS. The peak, breakdown, final, and setback viscosities of the control wheat flour were lower than those of the control PS, SPS, YS, and CS. The peak viscosity of wheat-PS mixtures was higher than those of the wheat-SPS, wheat-YS, and wheat-CS because of the higher phosphorus and lower amylose content of PS, which resulted in higher swelling of PS than that of SPS, YS, and CS. The breakdown viscosities increased as the starch content of the PS, SPS, and CS in the mixtures increased to up to the 50%, and the values tended to decrease in the wheat-YS mixture. The setback viscosities of wheat SPS, wheat YS, and wheat-CS increased significantly as the starch content increased from 10% to 50%, and that of wheat-PS dropped dramatically at 50%. The findings in this work provide evidence that tuber starches could be used as a partial substitute for wheat flour in some wheat-based products. (c) 2007 Elsevier Ltd. All rights reserved.