Green energy-assisted versus conventional solvent extraction for the recovery of phenolic antioxidants from marine macroalgae: A meta-analysis

Zahra Virginia Nabila (Undergraduate Programme in Pharmacy, Faculty of Health Sciences, Universitas Batam, Batam, Indonesia)
Heldi Candra (Undergraduate Programme in Pharmacy, Faculty of Health Sciences, Universitas Batam, Batam, Indonesia)

Natural Sciences Engineering and Technology Journal
Vol. 6 No. 1 (2026): Natural Sciences Engineering and Technology Journal

Background: Marine macroalgae are a renewable source of phenolic antioxidants. Energy-assisted extraction may replace prolonged solvent-intensive maceration, but its effect on recovery had not been quantitatively pooled. Methods: PubMed and Europe PMC were searched. Of 493 de-duplicated records, 35 full texts were assessed. Eligible reports compared energy-assisted and conventional extraction using paired arms from one homogenised macroalgal biomass. Hedges' g was pooled using random-effects models with cluster-robust inference; the ratio of means was a secondary measure. Risk of bias used laboratory analogues of five Cochrane domains. Results: Thirteen studies yielded 35 comparisons across 22 species and 93 estimates; ultrasound contributed 56 estimates, brown seaweeds 73, red seaweeds 20, and green seaweeds none. Energy-assisted extraction increased phenolic antioxidant recovery (cluster-robust Hedges' g = 8.62, 95% CI 2.98 to 14.26, p = 0.0063; ratio of means 1.385, 95% CI 1.149 to 1.671, a 38.5% gain) in a median 10 versus 960 minutes. The advantage persisted in 12 duration-matched comparisons. Heterogeneity was high (I2 = 87.8%); the prediction interval -2.26 to 16.16 included zero. No moderator survived robust testing. Supercritical carbon dioxide recovered 51.8% less than conventional extraction. Conclusion: Energy-assisted extraction recovered about 39% more phenolic antioxidant activity about 21 times faster. Direction was robust, but magnitude and certainty remained uncertain; a green label did not guarantee superior recovery.