Wong Kiing S, Lee Lillian, Yeo Leslie Y, Tan Ming K
School of Engineering, Monash University Malaysia, 47500 Bandar Sunway, Selangor, Malaysia.
Micro/Nanophysics Research Laboratory, RMIT University, Melbourne, Victoria 3001, Australia.
R Soc Open Sci. 2019 Mar 13;6(3):181560. doi: 10.1098/rsos.181560. eCollection 2019 Mar.
Seeds, which are high in protein and essential nutrients, must go through a hydration process before consumption. The ability to rapidly increase water absorption can significantly reduce the soaking time as well as the amount of energy needed for cooking seeds. Many studies in the literature employ high-power (10 W) low-frequency (10 Hz) ultrasound; although their results are very promising where more than 100% increase in water content can be obtained between the treated and untreated seeds, the high-power and low-frequency ultrasound often causes acoustic cavitation under high intensity, which can severely disrupt the cell walls and damage the seeds. In our study, however, we demonstrate that treating the seeds via a miniature surface acoustic wave device, which operates at low-power (10 W) and high-frequency (10 Hz) range, gives rise to a higher water absorption rate without the acoustic cavitations. By comparing the water content between the treated and untreated seeds, an increase of up to 2600% (for chickpeas) and 6350% (for mung bean) can be obtained after 60 min. A significantly higher water absorption in mung beans can be attributed to the larger pore size when compared with the acoustic wavelength in water, enabling an efficient transmission of acoustic wave inside the pores. Our results also indicate that the germination time can be reduced by half for treated seeds as compared to the untreated seeds.
种子富含蛋白质和必需营养素，食用前必须经过水合过程。快速增加水分吸收的能力可以显著减少浸泡时间以及烹饪种子所需的能量。文献中的许多研究采用高功率（10W）低频（10Hz）超声；尽管他们的结果很有前景，处理过的种子与未处理的种子相比含水量可增加100%以上，但高功率低频超声在高强度下常导致声空化，这会严重破坏细胞壁并损害种子。然而，在我们的研究中，我们证明通过微型表面声波装置处理种子，该装置在低功率（10W）和高频（10Hz）范围内运行，可产生更高的吸水率且不会产生声空化。通过比较处理过的种子和未处理的种子之间的含水量，60分钟后鹰嘴豆的含水量可增加高达2600%，绿豆的含水量可增加高达6350%。与水中的声波波长相比，绿豆中较大的孔径使得声波能够在孔隙内有效传播，这可以解释绿豆中显著更高的吸水率。我们的结果还表明，与未处理的种子相比，处理过的种子的发芽时间可减少一半。
