Glycerol-based extracts of Clitoria ternatea (Butterfly Pea Flower) with enhanced antioxidant potential

The butterfly pea flower (Clitoria ternatea) is a plant species that is commonly used in culinary products, as it adds a natural purplish-blue tint to dishes without artificial food colourings and is rich in antioxidants. In this study, glycerol was employed as an extraction solvent for the extraction of phenolic compounds from C. ternatea. Several studies have proven glycerol is an ideal green solvent to replace conventional solvents such as ethanol and methanol due to its ability to change the water polarity, thereby improving the extraction of bioactive compounds and recovering the polyphenols from natural products. We systematically reviewed the phytochemical content and antioxidant properties of aqueous, ethanol and methanol extracts of C. ternatea as a comparison to our study. Our results show that glycerol extract (GE) and glycerol/water extract (GWE) have demonstrated high phenolic and flavonoid profiles as compared to ethanol extract (EE) and water extract (WE). This study suggests glycerol as a promising extraction medium to extract higher concentrations of phytochemical contents from C. ternatea. It could be used as a natural source of antioxidant boosters, particularly in food preparation and cosmeceutical product development.