We previously reported that waxy potato and corn starch amylopectin pastes undergo a shear-thickening behavior that occurs at a low shear rate range of 5 to 25 s-1, and that the effect did not occur for waxy rice starch. Here, we show that the same gelatinized potato amylopectin subjected to a prolonged shear rate of 20 s-1 for 24 h at 5 °C forms a highly viscous gel having a 4-fold higher number of double helices than without shear. Shear-induced starch retrograded aggregates began forming within 20 min of treatment. Amylopectin double helices melted between 40-75 °C resulting in a steep decrease in the storage modulus, indicating that gel formation was caused by intermolecular double helices. Thus, a new phenomenon is reported whereby a waxy potato amylopectin paste, in the presence of long-term low shear, forms double-helical aggregated structures that considerably affects the material's rheological properties.

中文翻译：

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通过分子间双螺旋形成的长期低剪切诱导的高粘度蜡状马铃薯淀粉凝胶。

我们以前曾报道过，蜡状马铃薯和玉米淀粉支链淀粉糊剂会发生剪切增稠行为，这种行为会在5至25 s-1的低剪切速率范围内发生，而蜡质大米淀粉则没有这种作用。在这里，我们显示相同的糊化马铃薯支链淀粉在5°C下经受20 s-1的延长剪切速率持续24 h的情况，形成的高粘性凝胶具有比不剪切时高4倍的双螺旋数。剪切诱导的淀粉回生聚集体在处理后20分钟内开始形成。支链淀粉双螺旋在40-75°C之间熔化，导致储能模量急剧下降，表明凝胶形成是由分子间双螺旋引起的。因此，据报道出现了一种新现象，即蜡状马铃薯支链淀粉糊在长期低剪切力的作用下，