Drying Kinetics and Performance Analysis of Thermal Storage-Based Hybrid Greenhouse Dryer for Uniform Drying of Tomato Flakes

This communication focuses on the experimental investigation of mixed heat storage-based hybrid greenhouse dryer. The proposed system is a combination of a solar air heater and a greenhouse dryer. Mixed heat storage material is applied on the bed of the dryer, which is a combination of paraffin wax and black-painted gravel. Tomato flakes were selected for drying in both hybrid system and natural sun drying. Tomato flakes were rehydrated up to 1.29% and 10.10% under hybrid and open modes. Daily drying efficiency for drying tomato flakes in the proposed dryer was 50.18%, while it was 30.02% for open mode. Effective moisture diffusivity was 0.8666 × 10⁻¹⁰ m²/s and 11.650 × 10⁻¹⁰ m²/s for open and hybrid modes. The solar drying process improved physicochemical properties of tomato flakes, resulting in a shelf life extension. This finding highlights the great potential for hybrid solar dryer in the food industry and suggests that it could emerge as an efficient postharvest conserving method for seasonal consumable vegetables and fruits, mostly in developing nations.