Study on the Drying Kinetics of Tempeh from Different Raw Materials

Tempeh, offers high nutrition and digestibility but boasts a limited shelf life due to microbial activity. This study aimed to extend tempeh's shelf life by drying it into chips. Soybean, Indian dhal, and chickpea tempeh were sliced, dried at 80, 90, and 100°C, and analyzed for moisture content, drying curves, sorption characteristics, and drying kinetics. Higher temperatures and longer drying times reduced moisture content. The initial moisture content for all beans were calculated ranging of 150%-200%(wb) and moisture equilibrium were below 5%(wb). The GAB model showed equilibrium moisture content in tempeh chips which increased with relative humidity but decreased with temperature. Drying kinetics were modeled using Newton, Logarithmic, and Henderson and Pabis models and only Newton showed a clear decrease in soybean tempeh moisture ratio with increasing temperature.