Eutectic point and freeze-drying curve of Tremella fuciformis containing sucrose

Abstract

The eutectic point and drying curve of food multicomponent materials are the key to improve the efficiency of freeze-drying. The eutectic point, co-melting point, pre-freezing time, heating temperature and freeze-drying curve of Tremella fuciformis containing sucrose were investigated. The eutectic point and co-melting point temperature of materials were -15.49 °C and -8.35 °C respectively measured by differential scanning calorimetry (DSC). At the pre-freezing temperature of -25 °C for 3.5 h, the moisture of the sample was completely transformed into glassy ice. Different heating temperatures were set in sections during the drying process of multicomponent materials. The best heating temperature was 80°C for 3 hours, then 70 °C for 5 hours, then 60 °C for 12 hours, and finally 50 °C to constant dryness. Under the optimal operating conditions, Tremella fuciformis entered the desorption drying stage at the 8th hour, and the material could be dried to less than 5% moisture content at 25 h.