Enhancing rate of water absorption in seeds via a miniature surface acoustic wave device

Abstract

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 2 W) low-frequency (10 4 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 0 W) and high-frequency (10 7 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.

Effects of seed treatments on the germination of Golkoy palm (Phoenix theophrasti Greuter subsp. golkoyana Boydak)

“…All these increase alpha-amylase activity causing faster germination (Yaldagard et al, 2008;Luo, 2016). In chickpea and mung bean, 60-minute ultrasound treatment increased water absorption by 2600% and 6350%, respectively, compared to the control group (Wong et al, 2019). Shekarı et al, (2015) reported that ultrasonic treatment of sesame seeds (Sesamun indicum L.) increased germination.…”

“…The results of our study as regards the ultrasound treatment are consistent with the literature. Although there are no studies on the effects of ultrasound treatment on palm seeds, many studies on seeds of other species have shown that ultrasound treatment accelerates germination (Yaldagard et al, 2008;Wang et al, 2012;Luo, 2016;Nazari and Eteghadipour, 2018;Ameta et al, 2018;Wong et al, 2019). Ultrasound treatment accelerates and increases germination by enlarging the holes on the seed coat and facilitating water absorption.…”

Investigation of vegetative properties and generative production of the potential ornamental and narrow endemic species Verbascum yurtkuranianum (Scrophulariaceae) for ex situ conservation

“…Except for using chemical substances, other practices are available for inserting water into the seed via vacuum or pressure to promote germination (Miyoshi and Mii 1998;Custódio et al 2016;Katsalirou et al 2019). Another treatment that began to be used to terminate dormancy in seeds and enhance germination percentage is ultrasonic wave implementation (Luo 2016;Nazari and Eteghadipour 2017;Wong et al 2019).…”

The water path in plasma-treatedLeucaenaseeds

“…The study of the anatomical structures of the seed gives us complementary information in the analysis and description of the path travelled by the water inside the seed and of the metabolic modifications that occur internally during the imbibition process. In most of the botanical families, hilum and micropyle are the places of greater water intake in the seed (Serrato-Valenti et al, 1994; Kikuchi et al, 2006; Wong et al, 2019).…”

“…A palisade layer(s) in the seed coat (or fruit) is (are) responsible for the impermeability. The seed becomes permeable to water when an opening is formed via a specialized anatomical structure ('water gap') in the palisade layer (s), allowing water to enter the seed (Wong et al, 2019). The study of the anatomical structures of the seed gives us complementary information in the analysis and description of the path travelled by the water inside the seed and of the metabolic modifications that occur internally during the imbibition process.…”