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.