Ultrasound Assisted Extraction of Bitter Gourd Fruit (Momordica charantia) and Vacuum Evaporation to Concentrate the Extract

Bitter gourd (Momordica charantia) is a medicinal plant widely cultivated in Indonesia. The aim of this present study was to investigate application of ultrasound assisted extraction (UAE) and vacuum evaporation (VE) to process the fruit into a concentrate with focus on increasing extract's total phenolic content (TPC), antioxidant activity (AA) and storage stability. UAE was done under various level of time and temperature with the best combination found was 5 minutes and 25oC respectively. VE of the extract at 125 mmHg and water bath temperature set at 65oC showed that concentrate concentration factor (CF) was linearly correlated to its TPC and AA. Stability study of the concentrate under different storage temperature (4oC and 25oC) without preservative was done for 14 days. Higher CF enhanced shelf life and AA stability in both storage temperatures. This study concluded that UAE may reduce the required extraction temperature and time used for yielding extract with higher TPC and AA. Also, VE may concentrate the extract without damaging its TPC and AA. Lastly, VE may provide higher TPC, AA, and increasing storage stability while reducing extract volume compared to non-concentrated extract.