Investigation of the soybean infiltration process utilizing low-field nuclear magnetic resonance technology

by Lisha Guo, Han Wang, Chenru Hao, Ziqiang Chi, Li Cheng, Haibo Yang, Jing Zhang, Ruibin Zhao, Yanru Wu

This paper employs low-field nuclear magnetic resonance (LF-NMR) technology to meticulously analyze and explore the intricate soybean infiltration process. The methodology involves immersing soybeans in distilled water, with periodic implementation of Carr-Purcell-Meiboom-Gill (CPMG) pulse sequence experiments conducted at intervals of 20 to 30 minutes to determine the relaxation time T₂. Currently, magnetic resonance imaging (MRI) is conducted every 30 minutes. The analysis uncovers the existence of three distinct water phases during the soybean infiltration process: bound water denoted as T₂₁, sub-bound water represented by T₂₂, and free water indicated as T₂₃. The evolution of these phases unfolds as follows: bound water T₂₁ displays a steady oscillation within the timeframe of 0 to 400 minutes; sub-bound water T₂₂ and free water T₂₃ exhibit a progressive pattern characterized by a rise-stable-rise trajectory. Upon scrutinizing the magnetic resonance images, it is discerned that the soybean infiltration commences at a gradual pace from the seed umbilicus. The employment of LF-NMR technology contributes significantly by affording an expeditious, non-destructive, and dynamic vantage point to observe the intricate motion of water migration during soybean infiltration. This dynamic insight into the movement of water elucidates the intricate mass transfer pathway within the soybean-water system, thus furnishing a robust scientific foundation for the optimization of processing techniques.