Drying characteristics of jackfruit and snake fruit using freeze dryer

Jackfruit (Artocarpus heterophyllus Lam.) and snake fruit Salacca zalacca (Gaert.) Voss are tropical fruits that are rich in vitamins and minerals. Due to their specific aroma and unique taste, jackfruit and snake fruit have great potential to be processed into dried fruits and healthy snacks. In this work, jackfruit and snake fruit were freeze-dried using a self-designed laboratory-scale freeze dryer. The freeze dryer was constructed with a stainless-steel plate (3 mm thickness). The drying rates were determined with three different heating temperatures: 50, 60, and 70ºC. This study also investigated the effect of the freeze-drying process on the characteristics of dried fruit such as moisture content, texture, color, ascorbic acid content, and morphological of dried samples. Results showed that the heating temperatures were revealed to affect characteristics such as drying rate, final moisture content, texture, and ascorbic acid content. Increased drying rate and decreased drying time were observed with an increase in the dryer temperature. The sample resulted from 70ºC of heating temperature exhibited the optimum results in terms of hardness and ascorbic content preservation. The first-order kinetic model was the best fit for the prediction of drying kinetics of all materials. © Universiti Putra Malaysia Press.