NMR Relaxometry and Imaging to Study Water Dynamics during Soaking and Blanching of Soybean

Abstract

In the present study, soaking and blanching soybean were studied by time-domain nuclear magnetic resonance (TD-NMR) relaxometry and magnetic resonance imaging (MRI). Four proton fractions with different mobilities were observed in dried, soaked and blanched soybean samples, which reflects macromolecule, oil and water in different microenvironment of soybean. The proton distribution of soybean was significantly changed during soaking process. According to the result of MRI, water may initially penetrated into soybean from its radicle and micropyle. In terms of water distribution, the optimum soaking time for soybean was appeared to be 8 h. Blanching also significantly changed the proton distribution of soybean. During blanching, all four proton fractions became more mobile, and the accumulation of extracellular water was observed due to the partial destruction of cell/membrane integrity. The heat-induced variations of cotyledon tissues structure mainly occurred in the first 30 min, which implied blanching process should last at least for 30 min.