Study of physicochemical properties of normal and acetylated wheat and waxy corn starches and their effects on rheological properties of wheat flour dough

Physicochemical and rheological properties of native wheat starch (NWS), acetylated wheat starch (AWS), native waxy corn starch (NWCS) and acetylated waxy corn starch (AWCS) was investigated. Effects of incorporation of 5, 10 and 15% of those starches on rheological properties of wheat flour were determined by using a Rapid Visco Analyzer (RVA). Lower synersis and higher swelling power were observed in AWCS. The peak, breakdown, final, and setback viscosities of the control wheat flour were lower than those of the control NWS, AWS, NWCS and AWCS. The peak, Trough, breakdown and final viscosity of mixture of wheat with acetylated starches was higher than those of wheat with native starches because of the higher swelling power of acetylated starches than that of native starches whereas the setback viscosity of mixture of wheat with acetylated starches was lower than those of wheat with native starches. The peak and breakdown viscosity of wheat– NWCS and wheat- AWCS mixtures was higher than those of the wheat– NWS and wheat- AWS mixtures whereas the setback viscosity of wheat– NWCS and wheat- AWCS mixtures significantly was lower than those of the wheat– NWS and wheat- AWS.The peak, Trough, final,breakdown and setback viscosity increased as the starch content of the starches in the mixtures increased. The findings in this work provide evidence that acetylated starches specially WCS could be used as a partial substitute for wheat flour in some wheat-based products such as bread.