黑豆粉-小麦粉共混体系的线性和非线性蠕变-回复分析

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

利用蠕变-回复测试分析黑豆-小麦粉共混体系在线性和非线性黏弹性区域的流变特性。小麦粉添加黑豆粉后,面团的吸水率、形成时间均有提高,而面团的稳定时间呈现先增大后减小的趋势。蠕变-回复数据与4-因素Burgers模型拟合良好(R2>0.94)。在蠕变时间3、5、10、15 min的范围内,共混体系的λc、μc、Jcm、Jmax逐渐增大,Jro和回复率逐渐减小,Jco、Jro、Jcm总体上呈减小的趋势;形变后面团在3、5、10、15 min的回复时间内的回复率为63.51%~73.6%;在150、250、500、1000 Pa的剪切应力下,共混体系的Jco、Jcm、Jmax逐渐增大,μc、Jro、λr逐渐减小,回复率由89.99%降至32.36%。当小麦粉中黑豆粉的添加量为10%时,面团的弱化度最小,稳定时间较长。线性蠕变-回复分析结果为面团经过3 min蠕变时间达到稳态形变,继续延长蠕变时间,影响面团的弹性回复和回复速度,且面团的弹性网络会发生部分断裂;回复时间10 min时面团的回复率是73.6%。非线性蠕变-分析结果为面团在线性黏弹性区域外对剪切应力比较敏感,但仍具有典型的黏弹特性,提高剪切应力,面团的稳态剪切黏度变小,延迟弹性回复时间缩短。

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.