Physicochemical properties and salted noodle-making quality of purple sweet potato flour and wheat flour blends

The physicochemical properties of purple sweet potato flour (PSPF)-wheat flour blends and their effects on salted noodle-making quality were investigated. PSPF was substituted at levels of 5, 10, 15, 20, 25 and 30% for wheat flour. Addition of PSPF increased the gelatinization peak temperatures from 66.45 to 67.73C, but decreased paste viscosities at all substitution levels. Texture analysis showed that hardness of flour gels decreased as the amount of PSPF increased, while springiness reached the maximum value with 10% PSPF substitution. Farinographic tests indicated that dough stability decreased from 18.0 to 7.8min with the increasing levels of PSPF up to 30%. PSPF had a weakening influence on cooking and texture properties of noodles, but could be added to wheat flour under the level of 15% without drastically affecting salted noodle-making quality. PRACTICAL APPLICATIONS: Purple sweet potato flour (PSPF) could be served as a substitute for cereal flours, which enhanced products through color and nutrient. Salted noodles made by partially replacing wheat flour with 15% PSPF appeared the attractive color of pink redness and favorable cooking properties, which provided a basis to develop novel colored foods with good antioxidant capacity. © 2012 Wiley Periodicals, Inc.