Integration of Response Surface Methodology and FTIR-Multivariate Profiling for Optimizing Green Extraction of Antioxidants from Indonesian Mangrove Sonneratia alba

Hidden in the bark of an Indonesian mangrove lies a treasure trove of antioxidants—but how do we unlock it without harming the planet? Two green extraction methods just went head-to-head, and the winner might surprise you.

Mangroves are ecological heroes, but their chemical potential has been largely overlooked. Now, scientists are turning to Sonneratia alba, a mangrove species from Maumere Beach in East Nusa Tenggara, Indonesia, to find natural antioxidants. The challenge? Extracting these compounds efficiently and sustainably. Two eco-friendly techniques—microwave-assisted extraction (MAE) and ultrasound-assisted extraction (UAE)—were tested, with optimization guided by response surface methodology (RSM).

The results were striking. UAE, using ultrasound waves at 40°C for 30 minutes, delivered higher levels of phenolics (321.55 mg GAE/g) and flavonoids (11.48 mg QE/g), along with impressive antioxidant activity (IC₅₀ = 22.41 µg/mL). Meanwhile, MAE, using 700 W of microwave power, achieved a higher extraction yield (25.97%) in just 1 minute—though with slightly lower phenolic and flavonoid content.

FTIR spectroscopy confirmed the presence of aromatic, carbonyl, and hydroxyl groups, typical of phenolic and alkaloid compounds. So, which method wins? It depends on your goal: UAE for antioxidant-rich extracts, MAE for speed and yield. These findings pave the way for greener, smarter extraction of natural antioxidants from mangroves.

Key Points

• UAE yields higher phenolics and flavonoids with strong antioxidant activity.
• MAE achieves higher extraction yield in just 1 minute at 700 W.
• FTIR confirms aromatic, carbonyl, and hydroxyl groups in extracts.