Dough-making performance of composite whole-grain sorghum and whole-grain wheat flours as assessed by a micro-doughLAB assay

Abstract

BACKGROUND AND OBJECTIVE :

Owing to its climate-smart agronomic characteristics and health-promoting attributes, there is great interest in using sorghum in bread and other dough-based food product making. The objectives here were to develop a small-scale (4 g) Micro-doughLAB instrument-based assay to assess the dough-making performance of whole-grain sorghum flours in sorghum-whole grain wheat composites and to assess grain/flour factors affecting sorghum dough-making performance. FINDINGS :

The optimal Micro-doughLAB assay conditions for 50:50 ratio sorghum:wheat composites were 64% water absorption (14% flour basis), 30°C mixing temperature, 120 rpm mixing speed, and an 87 mNm target peak torque (much lower than wheat flour). The assay showed excellent precision, well within the AACC DoughLAB method specification. Data from 23 white normal sorghum lines revealed significant (p < .05) differences in dough peak torque, development time, stability, and softening. Peak torque was highly significantly correlated (p < .001) with flour damaged starch. CONCLUSIONS :

This assay has revealed that although sorghum lines differ in dough-making quality, none approach the quality of bread wheat. Further, damaged starch plays a predominant role in sorghum dough-making performance. SIGNIFICANCE AND NOVELTY :

Because of its small scale, this assay is particularly useful for the assessment of the dough-making flour quality of new sorghum lines.