Kinetics of a thin‐layer microwave‐assisted infrared drying of lentil seeds

Herein, we report the drying kinetics behavior of tempered lentil seeds (CDC Maxim variety) by utilizing a microwave‐assisted infrared thermal method and thereby presenting a successful mathematical model for it. The drying characteristics of lentils using thin‐layer microwave drying with and without hot air predrying were evaluated in a laboratory scale microwave dryer. The drying experiments were carried out at 300 and 750 W, and the predrying experiment was performed at room temperature (23°C). Out of several thin‐layer mathematical models evaluated with the experimental data, Page model has been found the most appropriate model to predict drying process of lentils with high value of coefficient of determination (0.995), low values of chi‐square (0.0012), root mean square error (0.0343), and mean relative percentage error (4.9997). Further, the influence of bioyield force and changes in the particle density of processed seeds have also been evaluated in the present study. The results showed that combination of low infrared power (0.375 kW) to the different microwave power levels led to a significant reduction of drying time. The results also showed that processing of lentil seeds significantly reduces the bioyield force of raw seeds, providing less firmness to the product and thereby shortening the cooking time. The above findings can facilitate the design and operation of infrared‐assisted microwave drying of other legumes.