Drying Kinetics, Statistical and Nutritional Analysis of a Drip Lock Sheet Greenhouse Dryer for Cucumis sativus Drying

This research focused on drying cucumber (Cucumis sativus) through multiple techniques, including Open Sun Drying (OSD) and a Drip Lock Sheet Greenhouse Dryer (DLSGD), functioning in natural and forced airflow modes. The effectiveness of the drying processes was analyzed using drying kinetics, statistical modelling, and nutrient retention studies. Under forced airflow at a flow rate of 1.2 m/s, the DLSGD reduced Cucumis sativus moisture levels from 94% to 11.5% within 4.5 days, whereas natural airflow achieved the same result in 5.7 days. In contrast, OSD needed 8 days for equivalent moisture removal. The drying patterns were described using twelve different predictive equations. The Midilli-Kucuk equation was found to be the most accurate for DLSGD in both airflow scenarios, while the Two-term equation best represented OSD. Nutritional evaluation revealed that DLSGD with forced airflow preserved 8.4% and 2.25% more carbohydrates than OSD and DLSGD with natural airflow, respectively. Furthermore, forced airflow resulted in higher calcium retention, while natural airflow better preserved Vitamin C content. Ultimately, the research identified forced airflow in DLSGD as the most effective drying method, surpassing others in drying rate and nutrient preservation, making it a viable option for industrial use where performance and product quality are essential.