Microwave-assisted extraction for Hibiscus sabdariffa bioactive compounds

Area of Science:

• Phytochemistry
• Green Chemistry
• Analytical Chemistry

Background:

• Hibiscus sabdariffa (H. sabdariffa) possesses phytochemicals, particularly phenolic compounds, linked to chronic disease prevention.
• Efficient extraction of bioactive compounds is crucial for maximizing their therapeutic potential.
• Microwave-Assisted Extraction (MAE) is a sustainable technology for plant-based compound isolation.

Purpose of the Study:

• To investigate the impact of MAE parameters on H. sabdariffa extract yield and bioactive compound concentration.
• To determine optimal MAE conditions for maximizing extraction efficiency.
• To characterize the phytochemical profile of the extracts.

Main Methods:

• MAE was employed to extract compounds from H. sabdariffa.
• Extraction parameters including temperature (50-150°C), ethanol concentration (15-75%), and time (5-20 min) were systematically varied.
• High-Performance Liquid Chromatography-Electrospray Ionization-Time-of-Flight-Mass Spectrometry (HPLC-ESI-TOF-MS) was used for extract characterization.

Main Results:

• The optimal conditions for overall extraction yield were determined to be 164°C, 60% ethanol, and 22 minutes.
• Specific conditions (164°C, 45% ethanol, 12.5 min) were identified as best for certain compound concentrations, though glycoside flavonoids degraded.
• Temperature and solvent concentration significantly influence MAE outcomes for H. sabdariffa.

Conclusions:

• MAE is an effective method for extracting bioactive compounds from H. sabdariffa.
• Optimizing temperature and ethanol concentration is critical for efficient MAE.
• Further research may be needed to mitigate degradation of specific compounds like glycoside flavonoids during extraction.