小麦淀粉的粒度分布、组分及糊化特性对氮硫肥的响应

为明确氮硫肥对小麦淀粉粒度分布及主要理化特性的影响,以强筋小麦品种西农9718和中筋品种陕农138为材料,采用不同氮硫肥水平进行处理,系统分析了小麦A、B淀粉的粒度分布、淀粉组成、膨胀势及糊化特性对氮硫肥的响应。结果表明,强筋和中筋小麦品种的淀粉粒度分布基本一致。A淀粉粒体积分布占总淀粉的74.95%～75.43%,但淀粉粒数量远少于B淀粉粒。A淀粉的直链淀粉、峰值黏度、低谷黏度、崩解值、最终黏度以及回生值高于B淀粉,而B淀粉有更高的支链淀粉、膨胀势和糊化温度。不同氮硫肥处理改变了小麦淀粉的粒度分布,进而影响淀粉的组成和糊化特性。在施氮(230kg.hm-2)条件下,强筋品种西农9718和中筋品种陕农138的A、B淀粉分别在硫肥施用量为46和56kg.hm-2时有较低的直链淀粉含量、较高的膨胀势及较好的糊化特性。陕农138淀粉的粒度分布、组成及糊化特性对氮硫肥的响应比西农9718更敏感。适当的氮、硫肥配施有利于改善小麦的淀粉品质。

Effect of Nitrogen and Sulfur Fertilizer on Granule Size Distribution, Composition and Pasting Properties of Wheat Starch

In order to test the effects of nitrogen and sulfur fertilizer on granule size distribution and physical and chemical properties of wheat starch,Wheat cultivars Xinong 9718 and Shaannong 138,responsible for strong-and weak-gluten types respectively,were grown at different combinations of nitrogen and sulfur fertilizers,the effects of nitrogen-sulfur on granule size distribution,composition,swelling power and pasting properties of wheat starch were analyzed.The results indicated that granule size distribution of wheat starch of Xinong 9718 and Shaannong 138 were consistent.A-type granule made up to 74.95%～75.43% of the total starch volume,but much less than the number of B-type granule.The amylose content,peak viscosity,trough viscosity,breakdown,final viscosity and setback of A-type granule were higher than B-type granule,and B-type granule had higher starch amylopectin content,swelling power and pasting temperature.Different fertilizer treatments changed the distribution of different sizes of wheat starch,thereby affecting the composition and pasting properties of starch.When nitrogen fertilizer was 230 kg·hm-2,A-type granule and B-type granule starch of Xinong 9718 and Shaannong 138 had lower amylose content,higher swelling power and better pasting properties at sulfur fertilizer 46 kg·hm-2 and 56 kg·hm-2,respectively.Starch granule size distribution,composition and pasting properties of Shaannong 138 were sensitive to fertilization.Appropriate nitrogen and sulfur fertilization will help to improve the quality of wheat starch.