Microwave Drying of Chili Pepper Slices: Estimating Moisture Loss and Color Changes and Characterizing Antioxidant Properties

Chili peppers ( Capsicum annuum L.), valued for their flavor‐enhancing properties, are rich in fiber, essential oils, vitamins, and bioactive compounds and exhibit strong antioxidant activity. Due to their high moisture, fresh chilies are dried using conventional methods to preserve quality; however, microwave drying has emerged as an alternative method for food drying applications, including chili pepper drying. Our objectives were to investigate the effect of microwave power levels (120–600 W) on moisture loss and color degradation using a kinetic modeling approach and to assess dried chili total color difference ( Δ E ), browning index (BI), total phenolic content (TPC), and antioxidant properties (DPPH, ABTS + , and FRAP). Microwave drying at higher power levels significantly reduced drying times ( p ≤ 0.05): 60 min at 120 W, 10.5 min at 480 W, and 7 min at 600 W. Drying at lower powers (120–240 W) yielded minimal color change, whereas BI increased at ≥ 300 W. Microwave power levels did not affect TPC and ABTS + antioxidant value. By contrast, DPPH antioxidant values decreased (from 185.44 to 101.00 μ mol Trolox equiv. TE g −1 ) as the microwave power was increased from 240 to 600 W, and the FRAP values decreased significantly from 129.5 to 25.76 μ mol TE g −1 at 120 and 360 W, respectively. Although the Midilli primary model provided the best fit, the secondary Weibull/power law model was found more suitable for predicting the moisture loss kinetics of chili peppers under different microwave power levels (root mean squared error RMSE 0.013–0.029). Given the rising consumer demand for chili‐based products, microwave drying can achieve similar product qualities as traditional drying while significantly reducing drying time. These findings can serve as a reference for spice processors to optimize color and antioxidant retention while increasing drying efficiency.