Valorization of Shrimp Shell Through Different Drying Methods: Impact on Kinetics and Powder Quality

Shrimp processing generates large amounts of byproducts such as shell, rich in valuable bioactive compounds, including proteins, lipids, minerals, and carotenoids. Their valorization into functional powders represents a sustainable approach for waste reduction and resource recovery. This study investigated the effects of three drying methods, namely sun drying, microwave drying, and convective air drying, on the drying kinetics and quality attributes of shrimp shell powder. The powders were evaluated in terms of antioxidant activity, chemical composition, and physicochemical and techno-functional properties, while structural and thermal characteristics were analyzed using FTIR and DSC techniques. The results showed that microwave drying significantly accelerated moisture removal (5.5 min), leading to the shortest drying time, whereas sun drying exhibited the slowest drying behavior (1680 min). Convective drying provided a balanced drying rate and better carotenoid levels (0.962 mg/g β-carotene equivalent against 0.916 and 0.714 mg/g for microwave and sun drying, respectively) and exhibited stronger antioxidant activity (IC50 = 95.67 ± 1.621 μg/mL). Microwave drying ensured higher lipid retention (3.38%) but showed only moderate functional performance, while sun drying led to lower biochemical stability and changes in structural characteristics. In conclusion, convective drying offered the best compromise between drying efficiency and product quality, highlighting its potential for the sustainable valorization of shrimp byproducts.