Heat Transfer Analysis in the Drying Process of Sweet Potato Leaves (Ipomoea batatas L.) Using a Tray Dryer

Abstract

Purple sweet potatoes (Ipomea batatas L.) have leaves that have the potential to be developed as functional foods, one of which is in the form of herbal tea. To meet product quality standards, particularly a maximum moisture content of 8% in accordance with SNI 3836:2013, an effective and controlled drying process is required. This study aims to analyze heat transfer in the drying process of sweet potato leaves using a tray dryer. The research method used is an experimental method with drying temperatures of 40–45°C and 50–55°C. The parameters analyzed included drying temperature, material mass, heat energy input, heat energy output, heat energy loss, and useful heat energy. The results showed that the heat energy input at a temperature of 40–45°C was 803.82 kJ with useful energy of 168 kJ, energy output of 157.655 kJ, and energy loss of 325.655 kJ. At a temperature of 50–55°C, the heat energy input increased to 1,148.57 kJ, with useful energy of 165.2 kJ, outgoing energy of 193.625 kJ, and lost energy of 356.025 kJ. The increase in temperature accelerated the decrease in moisture content and accelerated the drying process