School of Chemistry, The University of Melbourne, Melbourne, Vic 3010, Australia.
Ultrason Sonochem. 2012 May;19(3):421-6. doi: 10.1016/j.ultsonch.2011.08.006. Epub 2011 Sep 6.
A simple light microscopic technique was developed in order to quantify the damage inflicted by high-power low-frequency ultrasound (0-160 W, 20 kHz) treatment on potato starch granules in aqueous dispersions. The surface properties of the starch granules were modified using ethanol and SDS washing methods, which are known to displace proteins and lipids from the surface of the starch granules. The study showed that in the case of normal and ethanol-washed potato starch dispersions, two linear regions were observed. The number of defects first increased linearly with an increase in ultrasound power up to a threshold level. This was then followed by another linear dependence of the number of defects on the ultrasound power. The power threshold where the change-over occurred was higher for the ethanol-washed potato dispersions compared to non-washed potato dispersions. In the case of SDS-washed potato starch, although the increase in defects was linear with the ultrasound power, the power threshold for a second linear region was not observed. These results are discussed in terms of the different possible mechanisms of cavitation induced-damage (hydrodynamic shear stresses and micro-jetting) and by taking into account the hydrophobicity of the starch granule surface.
为了定量评估高功率低频超声（0-160 W，20 kHz）处理对水相淀粉颗粒造成的损伤，开发了一种简单的光镜技术。使用乙醇和 SDS 洗涤方法对淀粉颗粒的表面性质进行了改性，已知这两种方法可以从淀粉颗粒表面置换蛋白质和脂质。研究表明，在正常和乙醇洗涤的马铃薯淀粉分散体中，观察到两个线性区域。缺陷数量首先随超声功率的增加呈线性增加，直至达到阈值水平。然后，缺陷数量与超声功率之间再次呈线性关系。与未经洗涤的马铃薯分散体相比，乙醇洗涤的马铃薯分散体中发生转换的功率阈值更高。在 SDS 洗涤的马铃薯淀粉的情况下，尽管缺陷的增加与超声功率呈线性关系，但未观察到第二个线性区域的功率阈值。这些结果根据空化诱导损伤的不同可能机制（流体动力剪切应力和微喷射）进行了讨论，并考虑了淀粉颗粒表面的疏水性。
