Whole wheat flour (WWF) contains various kinds of functional ingredients, such as dietary fiber, resistant starch, minerals, etc., and bread containing WWF is in great demand in many countries because of its health benefits. Although dough with WWF often results in lower quality bread, previous studies suggested that this could be improved by the addition of suitable enzymes. This study investigated the effects of WWF substitution and enzyme treatments using α-amylase (AM) and hemicellulase (HC) on bread making qualities. Results showed that the addition of WWF produced dough with low gas retention of dough (GRD) and specific loaf volume (SLV). However, AM and HC drastically improved both GRD and SLV of WWF-substituted dough and bread by degrading damaged starch and hemicellulose. Thus, these results indicated that the treatments with suitable enzymes could drastically improve the bread making qualities of dough made with WWF.

Specialty breads substituted with non-wheat flour like purple sweet potato have been attracting attention because of their added nutrients, flavor, and color. Although the addition of non-wheat flour to specialty breads often results in lower loaf volume, this can be improved by enzyme treatments. In this context, this study investigated the effects of purple sweet potato powder (PSPP) substitution and enzyme treatments using α-amylase and hemicellulase on gassing power (GP), gas retention of dough (GRD), color and specific loaf volume (SLV) of bread. Results showed that the addition of PSPP produces bread crumbs with light purple color but low GRD and SLV of bread. On the other hand, α-amylase and hemicellulase improved the GRD, SLV and GP of PSPP-substituted bread by degrading the damaged starch and hemicellulose. Thus, these improved properties indicate acceptable quality of the bread.

Sweet potato is a nutritious, cost-effective and abundantly available food crop in Asia. In an effort to utilize sweet potato for food processing, the effects of purple sweet potato powder (PSPP)-supplementation on the quality of fresh pasta was determined. Results showed that PSPP-supplementation produced fresh pasta dark purple in color, attributable to the intrinsic anthocyanin content. Moreover, PSPP provided a higher amount of gelatinized starch, resulting in softer and more elastic raw fresh pasta; and the boiled fresh pasta showed a softer texture, as indicated by its hardness, rupture force and energy. However, PSPP-supplementation decreased the cooking weight gain of fresh pasta. Sensory evaluation rated the quality of boiled fresh pasta with 7.5% and 10% PSPP as more acceptable and equally acceptable as the control, respectively. Thus, this study suggests that PSPP-supplementation results in an acceptable noodle product, potentially increasing the utilization of purple sweet potato.