Effect of Ultrasound and Microwave Pretreatment on Soaking and Drying Behavior of Kidney Beans ( Phaseolus vulgaris L.): Kinetics and Physical Attributes

The aim of this study is to assess the impact of ultrasound (US) and microwave (MW) pretreatments on the soaking behavior of kidney beans ( Phaseolus vulgaris L .), as well as their effects on drying kinetics, mass transfer parameters at 45°C, 55°C, and 65°C, and associated physical properties. Although both technologies have been studied separately, limited work has compared their effects on hydration–drying behavior in kidney beans, creating a gap this study addresses. The Weibull model was effectively predicting the soaking kinetics as evidenced by high R 2 values (0.99675–0.99926) and low RMSE (0.01967–0.00883) for both treated and untreated samples. Enhanced soaking methods led to higher water absorption and increased sphericity and surface area, indicating quicker and more uniform hydration. The logarithmic thin‐layer model was the best for predicting drying behavior as it had the highest R 2 (0.99472) and the lowest RMSE (0.01099). The ultrasound‐treated seeds were the fastest in soaking and drying, which can be attributed to the microstructural changes induced by cavitation. Moisture diffusivity increased with temperature, and it was within the ranges of 7.63 × 10 −9 to 1.91 × 10 −8 m 2 /s (microwave), 6.66 × 10 −9 to 1.33 × 10 −8 m 2 /s (ultrasound), and 3.24 × 10 −9 to 9.72 × 10 −9 m 2 /s (untreated). The color quality was effectively influenced by pretreatments and drying. A darkening effect was observed in microwave soaking (lower L *, higher ∆ E *), whereas the brightness was retained by the ultrasound. PCA separated the treatments, associating the ultrasound with improved hydration, stability, quicker drying, and color retention, which is in line with enhanced drying efficiency, nutrient preservation, and scalable kidney bean processing.