Department of Food Science and Nutrition, School of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China.
Molecules. 2013 Apr 24;18(5):4858-67. doi: 10.3390/molecules18054858.
Little is known about the efficacy of pulsed ultrasound compared with continuous ultrasound. Previous studies on the efficacy of pulsed ultrasound were not systematic and gave different results. In this study, the effects of pulse length, pulse interval, pulse length × pulse intervals, and treatment time on sonochemical activity were investigated using a simple oxidation of iodide method and a comparison of the efficacy of pulsed ultrasound and continuous ultrasound is made. The results showed that the main factor in the efficacy of pulsed ultrasound was pulse length when pulse length varied from 0.1 to 1 s. However, the main factors were pulse length, the pulse length × pulse interval, and pulse interval when pulse length varied from 1 to 9 s. Pulsed ultrasound had no effect when the pulse length was 0.1 s; however, the sonochemical activity of pulsed ultrasound decreased compared to continuous ultrasound as the pulse length varied from 0.1 to 1 s. The sonochemical activity of pulsed ultrasound either increased or decreased compared to continuous ultrasound when pulse length varied from 1 to 9 s, but the increase or decrease had no clear trend. The sonochemical activity was constant at T(on)/T(off) = 2 s/2 s and slightly decreased at T(on)/T(off) = 3 s/2 s with time, whereas the sonochemical activity of continuous ultrasound significantly decreased with time. Enhancement or reduction of sonochemical activity of pulsed ultrasound compared to continuous ultrasound depended on the pulse length and pulse interval.
关于脉冲超声与连续超声的疗效相比，人们知之甚少。以前关于脉冲超声疗效的研究不是系统的，结果也不尽相同。在这项研究中，使用简单的碘化物氧化法研究了脉冲长度、脉冲间隔、脉冲长度×脉冲间隔以及处理时间对声化学活性的影响，并对脉冲超声和连续超声的疗效进行了比较。结果表明，当脉冲长度从 0.1 秒变化到 1 秒时，脉冲超声疗效的主要因素是脉冲长度。然而，当脉冲长度从 1 秒变化到 9 秒时，主要因素是脉冲长度、脉冲长度×脉冲间隔和脉冲间隔。当脉冲长度为 0.1 秒时，脉冲超声没有效果；然而，当脉冲长度从 0.1 秒变化到 1 秒时，脉冲超声的声化学活性比连续超声降低。当脉冲长度从 1 秒变化到 9 秒时，脉冲超声的声化学活性与连续超声相比要么增加要么减少，但增加或减少没有明显的趋势。当 T(on)/T(off) = 2 s/2 s 时，声化学活性是恒定的，随着时间的推移，当 T(on)/T(off) = 3 s/2 s 时略有下降，而连续超声的声化学活性随着时间的推移显著下降。与连续超声相比，脉冲超声的声化学活性增强或减弱取决于脉冲长度和脉冲间隔。
