A novel model system for characterization of double helix in starch is developed using branched dextrin (BD) purified from Nägeli amylodextrin by repeated precipitation in 10% ethanol. The solution of one‐time precipitated BD (BD1, 3% in water) starts to develop turbidity in 8 h of incubation at 4 °C. Volume particle size distribution during the association of four‐time precipitated BD sample (BD4) is analyzed using dynamic light scattering. The mean diameter of the particles jumps from 3.8 to 170 nm between 2 and 2.5 h of incubation, suggesting a prerequisite lag time for maturation of intermolecular association of BD4. Flakes of BD4 in water exhibit a B‐type crystal by X‐ray diffraction analysis. A screening system of additives affecting turbidity development of BD1 in water is applied for 82 compounds, and sodium tetraborate (borax) significantly retards the development. Borax affects the rate of turbidity development and maximum turbidity at the plateau stage in a concentration‐dependent manner. Borax is also added to rice starch gel, which reduces the increase of hardness of the gel during retrogradation. This novel assay system with BD can be used for screening and evaluation of additives affecting starch gelation and retrogradation.

中文翻译：

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水中Nägeli淀粉糊精中支链糊精的关联用于筛选影响淀粉凝胶特性的添加剂

利用从Nägeli淀粉糊精中纯化的支链糊精（BD），通过在10％乙醇中反复沉淀，开发了一种新型的表征淀粉双螺旋的模型系统。一次性沉淀的BD（BD1，在水中3％）的溶液在4°C孵育8小时后开始出现浑浊。使用动态光散射分析四次沉淀的BD样品（BD4）结合期间的体积粒径分布。在孵育2至2.5小时之间，颗粒的平均直径从3.8纳米跃升到170纳米，这表明BD4分子间缔合成熟的必要滞后时间。通过X射线衍射分析，水中的BD4薄片呈现B型晶体。筛选了影响BD1在水中浊度发展的添加剂筛选系统，用于82种化合物，四硼酸钠（硼砂）显着阻碍了发育。硼砂以浓度依赖的方式影响高原阶段的浊度发展速度和最大浊度。硼砂也被添加到大米淀粉凝胶中，这降低了凝沉过程中凝胶硬度的增加。这种具有BD的新型测定系统可用于筛选和评估影响淀粉胶凝和回生的添加剂。