Development of a Novel Image Analysis Technique to Detect the Moisture Diffusion of Soybeans [<Emphasis Type="Italic">Glycine max</Emphasis> (L.)] During Rehydration Using a Mass Transfer Simulation Model

The change in the moisture content of soybeans during a rehydration process at 25 °C was investigated. Peleg’s equation was suitable for describing the soaking characteristics of the soybean with a R² value of 0.98. The soaking time to achieve the target moisture content of soybeans (33.33%) was estimated to be 14.59 min by the Peleg model. The mass transfer coefficient (k) for the mass transfer simulation was determined with two calculation steps using the Omoto model and the simulation models. The most suitable k value for the simulation was determined to be 6.0?×?10^?7 m²/s, which is higher than the apparent k value obtained from the Omoto model. The diffusion simulation for the internal diffusion of the soybean after soaking was conducted for 180 min and the cross-section of soybeans was analyzed using an image processing technique during the diffusion process. The image analysis detected a moving layer during the diffusion process and the moisture content at the layer was determined to be 32.08% (±?0.34) based on the results of the simulation model.