Kinetics and mathematical models of date paste dried using a convective infrared dryer

<br>Achieving the desired level of caramelisation in a date powder requires considerable effort. Consequently, an assessment was conducted on efficacy of thin-layer infrared dehydration for date paste. Various parameters were considered, including airflow velocities of 0.5, 1.0, and 1.5 m·s^–1, radiation intensities of 0.076, 0.1528, and 0.228 W·cm^–2, and date paste layer thicknesses of 3 mm and 5 mm. The study's findings indicated a positive correlation between drying rate and lowering airflow velocity and a negative correlation between drying time and decreasing airflow velocity, the thickness of date paste, and rising intensity of infrared. The effective moisture diffusivity (<i>D</i>_eff) was caculated by employing Fick's diffusion equation. For all situations under investigation, the mean values were within the range of 3.94 × 10^–11 m²·s^–1 to 6.01 × 10^–10 m²·s^–1. A relationship has been established between <i>D</i>_eff and moisture content. Seven distinct mathematical models were subjected to rigorous validation by applying non-linear regression analysis, aiming to accurately characterise the drying process of date paste. The modified two-term model provided the most accurate forecast of the drying process for date paste layers.