Abstract : Chlorophyll is a natural pigment, which exhibits strong antioxidant and antimicrobial activities, but has not been widely used in industrial applications due to low extraction efficiency and instability. Therefore, this work aimed to improve chlorophyll extraction from Hibiscus mutabilis leaves through ultrasonic-assisted extraction with different polarity solvent systems. The polarity of the solvent system affected the phytochemical characteristics and bioactivities of the extract. Five solvent systems (acetone/hexane (1:1), acetone/water (1:1), ethanol/water (1:1), acetone, and hexane) were compared for extraction yield, phytochemical content, and biological activities. The acetone/hexane (1:1) solvent system gave the highest chlorophyll content (22.48 mg/L) and pheophytin content (19.32 mg/L), leading to the highest extraction yield of 23.57%. This extract also showed the maximum radical scavenging effect with an IC50 value of 68.1 μg/mL and the highest antimicrobial activity, with inhibition zones of 35 mm against Escherichia coli and 32 mm against Staphylococcus aureus. These results show that the solvent polarity during extraction plays a key role in enhancing both extraction efficiency and bioactivity. The results also demonstrate the potential of Hibiscus mutabilis leaf extract as a natural and sustainable preservative for use in food, cosmetic, and pharmaceutical products.

Keyword :Acetone/Hexane, Antimicrobial Activity, Chlorophyll Extraction, Hibiscus Leaves, Pheophytin, Solvents