Solar Valorisation of Carob Leaves (Ceratonia siliqua) Using a Solar Convective Dryer

The preservation of biological products during storage and transportation is a major issue taking into consideration theshort shelf-life of most natural foods and plants. Hot air dryingusingthermalenergy derived from the sun is the most operated technique to extend the shelf-life of plants and food materials. The investigation of this study proposes to consider solar drying as a technique of carob leaves preservation, by determining its drying kinetics and using a solar drier designed for agricultural products. The experiences were conducted under four temperatures of drying air 40, 50, 60 and 70°C and airflow of 300 m3 h–1 inside the drying chamber. Throughout the drying studies, the air-drying temperature was ranged from 26 to 39°C and the relative humidity of the ambient air was in the range of 10 to 37%. Consequently, the diffusion of water inside the product was increased with the augmentation of air-drying temperature. In order to evaluate the temperature effect on the water diffusion, the activation energy value was determined for carob leaves.