Wx蛋白缺失对淀粉理化特性和面条品质的影响

 【目的】对Wx蛋白缺失影响小麦淀粉理化特性和面条加工品质的情况进行探讨。【方法】以6类Wx蛋白组成的14个品种为试材，测定其淀粉理化特性和面条品质，进行统计分析。【结果】Wx亚基的数目对其酶蛋白和直链淀粉含量有显著影响，随着Wx亚基数目的增加，Wx蛋白和直链淀粉含量相应升高，面粉膨胀势和峰值粘度呈现下降的趋势，但面条品质的变化并不表现完全一致。糯小麦绝大部分淀粉理化指标显著较低。不同Wx亚基对淀粉理化特性和面条品质的影响也存在一定的差异，缺失Wx-B1亚基对直链淀粉合成的影响最大，其次是Wx-D1亚基，缺失Wx-A1亚基作用最小。3类单一Wx亚基缺失材料中，Wx-B1亚基缺失品种直链淀粉含量最低，膨胀势和RVA峰值粘度最高，面条评分最高。【结论】从不同Wx亚基缺失类型小麦品种看，面条评分与直链淀粉含量、膨胀和糊化特性之间并不是简单的直线关系，尤其是直链淀粉含量，而是有一个合适的范围，在这个范围内随着直链淀粉含量的下降，膨胀势和峰值粘度升高，面条评分上升，超出这一范围面条评分下降。

Effects of Wx Protein deficiency on Starch Physiochemical Properties and Noodle Quality

The contents of enzyme and amylose, affected by Wx protein deficiencies significantly, were increased correspondingly with Wx protein number. In contrary, flour swelling power and starch pasting peak viscosity decreased, while noodle quality was not consistent with Wx protein lacking. Most starch physiochemical properties of waxy cultivars were lower significantly than that of other types. Different Wx subunit influenced starch physiochemical properties and noodle quality differently, and the Wx-B1 subunit lacking had greatest effect on amylose synthesis, then the Wx-D1 subunit lacking, and the Wx-A1 lacking least. The cultivar null in Wx-B1 subunit, with lowest amlose content and highest flour swelling power and peak viscosity, scored highest in noodle quality among three types with each subunit lacking. Conduced from the cultivars with different Wx protein composition, noodle score was not linear correlated to amylose content, flour swelling power and peak viscosity, especially for amylose content. Therefore, the cultivar suitable to make noodle should be confined in reasonable amylose content, and both flour swelling power and peak viscosity and noodle score increased with the decrease of amylose content between the confine, as well as noodle quality, while noodle score decreased beyond the confine.