Linear and Nonlinear Creep-Recovery Analysis of Black Bean-Wheat Flour Blend System

Abstract

The creep-recovery test was used to analyze the rheological properties of black bean-wheat flour blends in linear and nonlinear viscoelastic regions. After adding black bean powder to wheat flour, the water absorption rate and development time of the dough were both increased, and the stable time of the dough showed a trend of increasing first and then decreasing. Creep and recovery data fitted well with the 4-element Burgers model (R2>0.94). During the creep time of 3、5、10 and 15 min, the λc、μc、Jcm、and Jmax of the dough gradually increased, the Jro and the recovery rate gradually decreased. Jco、Jro、Jcm generally showed a decreasing trend. After the deformation, the recovery rate of the dough in the recovery time of 3、5、10 and 15 min was 63.51%～73.6%. Under the shear stress of 150、250、500 and 1 000 Pa, the Jco、Jcm and Jmax of the dough gradually increased, μc、Jro、λr and recovery rate dropped from 89.99% to 32.36%. When the amount of black bean flour added in wheat flour was 10%, the weakening of the dough was the smallest and the stable time was relatively longer. The Linear creep-response analysis results showed that the dough had reached steady shear during the creep time of 3 min, prolonging of the creep time affected the elastic recovery and recovery speed of the dough, and the elastic network of the dough was broken partially; the recovery rate of the dough was 73.6% at the recovery time of 10 min. The nonlinear creep-analysis results showed that the dough was sensitive to shear stress outside the linear viscoelastic region, but it still had typical viscoelastic properties,improved the shear stress, reduced the steady shear viscosity of the dough, and accelerated the delayed elastic recovery.

Keywords

• wheat flour
• black bean powder
• creep-recovery
• viscoelasticity
• burgers model
• elastic network