红花甜荞籽粒淀粉的理化特性

摘要

为明确红花甜荞籽粒淀粉理化特性,选用12个红花甜荞品种为材料,分析了其淀粉颗粒形态、粒度分布特征、直链淀粉含量、溶解度、透明度及糊化特性以及品种间差异.结果表明,红花甜荞淀粉颗粒多为不规则多角形和球形,多角形多且颗粒较大,球形颗粒较少且颗粒小,淀粉粒径范围介于0.38~25.78μm；品种间淀粉粒径、直链淀粉含量、溶解度、透明度存在显著性差异(P<0.05)；起始糊化温度在62.80~72.60℃,峰值黏度在126.58~141.00 RU；品种间谷值黏度、最终黏度、破损值、回生值和峰值时间差异显著.定边甜荞谷值黏度大,为118.00 RU；破损值及回生值小,分别为13.00和57.33 RU；达到峰值时间最长,达5.80 min；淀粉糊稳定性好.因此,在进行优质专用品种选育和产品加工时,应根据不同目标选择不同的甜荞品种.%In order to understand the physicochemical characters of common buckwheat starch, 12 varieties of common buckwheat were planted in the research farm of the Yan’an Institute of Agricultural Sciences and the granule morphology, solubility, transparencies, gelatinization and viscosities of their starch granules were investigated in this study. The starch granules’shapes and sizes were examined by Scanning Electron Microscope (SEM). The starch granule diameters, amylase contents, solubility and transparencies were found to significantly differ among the different test varieties(P<0.05). The starch granules of the test varieties had irregular polygonous and global shapes and the granules of the varieties with the former shapes were larger and numbered more than their ones with the latter shapes. The granule diameters of the test varieties ranged within 0.38-25.78μm. The starch granules of Ning D07-1, Wuqi Honghuaqiao-2, Pingxuan 01-036, Dingbian Tianqiao and D07-2 were polygonous with clear-cut edges and the starch granules of Qingyang Honghuaqiao, Zhidan Honghuaqiao and Dingbian Tiaoqiao were global and smooth at high percentages. The starch granules of the varieties presented similar two-peak size distributions of which the first peak appeared at the granule diameter of 1 μm and the second peak appeared at the granule diameter of 15 μm and the former peaks were higher than the latter ones. Ning D07-3 had the highest amlyose content of 43.06% and Ning D07-2 had the lowest amlyose content of 36.63%, and the other varieties had amlyose contents that ranged between 36.82%-42.22%. The amlyose content of Ning D07-3 and Pingxuan 01-036 were significantly higher than those of the other varieties and the amlyose contents of Wuqi Honghuaqiao-1 and Ning D07-2 were significantly lower than those of the other varieties. The starch solubility of the varieties increased with increased temperatures and that significantly differed;and at 80 and 90℃, the starch solubility of Menggu 20, Wuqi Honghuaqiao-1, and Dingbian Tianqiao were significantly lower than those of Ning D07-1, Wuqi Honghuaqiao-2 and Qingyang Honghuaqiao. The starch paste transparencies of the varieties significantly differed, with Wuqi Honghuaqiao-2 presenting the highest transparency of 8.65%, and Menggu 20 presenting the lowest transparency of 7.37%. The starch paste retrogradation of the varieties tended to increase slowly at first and then quickly with time, with the starch paste retrogradation of Zhidan Honghuaqiao, Xinong 9976,Wuqi Honghuaqiao-1, NingD07-2 and Xinong 9978 standing higher and the starch paste retrogradation of Ning D07-1, Wuqi Honghuaqiao-2, Qingyang Honghuaqiao, Menggu20 and Pingxuan 01-36 standing lower. The initial starch pasting temperatures and peak viscosities of the test varieties ranged between 62.80-72.60℃ and 126.58-141.00 RU, respectively. The starch trough viscosities, final viscosities, breakdowns, setbacks and peak viscosity times of the test varieties significantly differed. The highest viscosity was 118.00 RU, and the lowest breakdowns and setbacks were 13.00 RU and 57.33 RU respectively. The longest peak viscosity time was 5.80 min, and the most stable starch pastes appeared in Dingbian Tianqiao. These results indicated that the test varieties had significantly different starch characters and thus, while the varieties were used to process buckwheat starch or flour, their different starch characters should be taken into account.