Characterization and Comparison of the Freeze-Drying Process at PT. Hijaukan Bumi Lestari and i3L

Abstract

Freeze-drying, also known as lyophilization, is a drying method that is superior to other drying methods in that it retains aroma, flavor, aroma, and nutrition better while also extending the overall shelf-life of fruits and vegetables. Freeze-drying follows 3 stages/phases, freezing, primary drying, and secondary drying. Different machines have different freeze-drying settings where PT. Hijaukan Bumi Lestari utilizes a temperature-sensitive probe and i3L follows coordinated time stages to move the freeze-drying process of strawberry and dragonfruit. The study's goals were to compare the efficiency of both machines using data recorded on the machines themselves. The freeze-drying results based on temperature vs. time were also characterized in order to identify the three main freeze-drying steps. The final objective was to see if there is a significant difference in freeze-drying strawberry and dragonfruit based on the shelf and product temperature differences (ΔT) of both machines. According to the results, PT. Hijaukan Bumi Lestari's freeze-drying process took a shorter time than the i3L’s machine. To measure the efficiency of each machine, the temperature difference (ΔT) between the product and shelf was calculated where PT. Hijaukan Bumi Lestari has higher temperature discrepancies compared to i3L’s machine which means that it requires more considerable energy to undergo the freeze-drying process. Furthermore, the Mann-Whitney U test was used to compare the differences between freeze-drying strawberry and dragonfruit based on the ΔT where strawberry and dragonfruit were not significantly different when dried at PT. Hijaukan Bumi Lestari's machine, but they were significantly different when dried at i3L's machine.