茶多糖对小麦粉流变性的影响

Effect of Tea Polysaccharide on Rheology of Wheat Flours

利用胶体流变性的原理,分析了茶多糖和2种小麦粉的流变性及茶多糖对小麦粉流变性的影响,同时对小麦淀粉微观结构变化进行了分析。结果表明:小麦淀粉颗粒膨胀势随糊化温度的升高产生明显的变化,淀粉颗粒在70℃时开始出现破裂;当达到100℃时,几乎所有的淀粉颗粒破裂,膨胀率达到158.91%;蛋糕粉膨胀率上升趋势与面包粉基本相同,但略微大于面包粉的膨胀率。小麦粉的胶体溶液的表观粘度与浓度呈正相关,为假塑性流体;茶多糖在10%以下呈牛顿力学性质,为牛顿流体;茶多糖溶液浓度在10%以上为假塑性流体。当茶多糖的浓度达到4%时,小麦粉的表观粘度达到最大,但2种小麦粉加入茶多糖所呈现出表观粘度的变化有较大差异,蛋糕粉的粘度增长率要远远大于面包粉的粘度增长率。

The rheological properties of tea polysaccharide and two kind of wheat flour were analyzed as well as the wheat starch microstructure. The results indicated that the inflation trends of wheat starch at different temperature changed obviously. The starch granules began to inflate at 70℃. All starches pellet bro- ken when the temperature went up to 100℃, the expansion rate achieved 158.91%. The expansion trend of cake flour is similar to that of bread flour. The apparent viscosity of wheat flour was proportion to the content of wheat flour, belonged to non--Newtonian flow. The tea polysaccharide was Newtonian flow at 1%- 8%. When tea polysaccharide concentration above was 10% , it showed non--Newtonian flow. When the tea polysaccharide density was up to 4%, the apparent viscosity of wheat flour get to the maximum. The apparent viscosity in two kinds of wheat flour showed significant difference when adding tea polysaccharide. The increment of viscosity for cake flour was more than that of bread flour.