蛋白质和淀粉含量对小麦面团流变学特性的影响

以小麦强筋品种山农12和中筋品种山农11为材料，利用面团重组方法，在保持面粉中其他成分不变的情况下，配成不同蛋白质和淀粉含量的样品，研究了蛋白质和淀粉含量对面团流变学特性的影响。结果表明，当蛋白质含量依次为120%、140%和160%时，两品种面团的峰值高度和峰值宽度呈显著增加趋势(P<0.05)，最大抗延伸阻力山农12分别为40.7 CK）、49.8 g、59.0 g和71.6 g，山农11分别为20.6（CK）、29.5 g、32.1 g和36.0 g，呈增加趋势，而延伸性变化不大；当淀粉含量依次为85%、90%和95%时，两品种面团的峰值高度和峰值能量呈显著降低趋势(P<0.05)，延伸性山农12 分别为110.8 mm（CK）、68.8 mm、59.2 mm和36.5 mm，山农11分别为81.6 mm（CK）、75.8 mm、59.1 mm和50.3 mm，呈降低趋势，而最大抗延伸阻力变化不大。

Effect of Protein and Starch Contents on Wheat Dough Rheological Properties

Protein and starch are the abundant constituents in wheat flour and the major contributors for dough rheological properties.Most of the previous researches related to dough rhelolgical properties focused on the effect of protein and its components,but a very few on the effect of different protein and starch contents.It is well known that both protein and starch are important components to evaluate the quality of wheat flour,and closely related to dough rheological properties.In the present study,we used a strong gluten wheat cultivar Shannong 12 and a medium-strength wheat cultivar Shannong 11 to study the effect on dough rheological properties under different protein or starch percentage,in order to reveal the functions of protein and starch in dough and flour products,and therefore give advice on wheat breeding for quality.The fractionation and reconstitution method was adopted to make the flour samples have various protein and starch contents with a constant background composition.The results indicated that peak height(PH) and peak width(PW) of two kinds of dough were significantly increased(P<0.05) compared with those of control when protein content was increased from 100% to 120%,140%,and 160%,the maximum resistances(MR) were increased from 40.7 to 49.8 g,59.0 and 71.6 g in Shannong 12 and from 20.6 to 29.5 g,32.1 and 36.0 g in Shannong 11,respectively.However,the extensibilities (EX) of these two doughs changed not obviously compared with those of control.PH and peak work input(PWI) of two kinds of dough were significantly decreased(P<0.05) with the increase of starch content.When the starch contents were increased from 81.11%(Shannong 12) and 83.85%(Shannong 11) to 85%,90%,and 95%,the EX was decreased from 110.8 to 68.8 mm,59.2 and 36.5 mm in Shannong 12 and from 81.6 to 75.8 mm,59.1 and 50.3 mm in Shannong 11,respectively.However,the MR of these two doughs changed not too obviously compared with those of control.