Food waste poses major environmental challenges globally. Using technologies that enhance biowaste value and protect the environment is a promising solution. This research examined the drying kinetics of eggplant ( Solanum melongena L.) peel and pulp waste (EPPW) in an infrared (IR)‐convective dryer that operates in forced convection of unheated air (UH‐air). Operating parameters, including IR power (1000, 1500, and 2000 W), sample thickness (2, 4, and 6 mm), and UH‐air velocity (0.5, 1.25, and 2 m/s), were evaluated to optimize drying performance. Response surface methodology (RSM) was employed for settings of operating variables, and the parameters’ effects on drying characteristics and some quality attributes were analyzed using analysis of variance (ANOVA). Higher IR power, reduced sample thickness, and UH‐air velocity decreased drying time while enhancing energy efficiency (EE). Effective moisture diffusivity values ranged from 1.046 × 10 −10 to 1.113 × 10 −9 m 2 /s, with specific moisture extraction rate (SMER) and specific energy consumption (SEC) at 0.07–0.24 kg/kWh and 4.18–14.30 kWh/kg water evaporated, respectively. Greenhouse gas (GHG) emissions were minimized as IR power increased and as sample thickness and UH‐air velocity decreased. In addition, total anthocyanin (TA) content increased significantly after drying (74.94–290.24 mg cyanidin‐3‐glucoside CGE.100 g −1 dm), and water activity ensured product stability. The Weibull distribution model best predicted drying kinetics. The drying parameters were optimized for the determined restrictions, leading to 2000 W IR power, 6 mm sample thickness, and 0.84 m/s UH‐air velocity. IR‐convective drying efficiently improves the drying process of biowaste. Future studies can apply this approach to various agricultural by‐products to promote sustainability.
Jafari et al. (Thu,) studied this question.