Freeze drying of natural deep eutectic solvent (NADES) extract of green coffee bean (Coffea canephora Pierre ex A. Froehner)

Natural Deep Eutectic Solvent (NADES) as green solvent had succeeded in attracting caffeine and chlorogenic acid from green coffee beans. NADES has very low eutectic points and chlorogenic acid in extract is thermolabile so that freeze-drying is suitable as drying method. This study aimed to produce and investigate the effect of addition of maltodextrin, Arabic gum and Aerosil® in freeze-dried NADES extract of green coffee beans and obtain the validation method of NADES extract by HPLC. In pretreatment of freeze drying, addition of water was needed as antisolvent and excipients (maltodextrin, Arabic gum, and its combination at 25%, 30%, and 35% and Aerosil® at 1%, 2%, and 3%) were added to improve the quality of dried extract. All samples were frozen first at -80°C for 24 hours, then freeze drying was carried out for 26 hours under pressure conditions of 0.036 mbar and ice condenser temperature of -104.7°C. The freeze-dried products were evaluated for caffeine and chlorogenic acid content, yield drying, and moisture content. Caffeine and chlorogenic acid levels had a significant difference (p