Bioactive Compounds Extraction From Moringa oleifera Leaves: A Comparative Study of Vacuum-Assisted and Bed-Stirred...

Moringa oleifera leaves are a rich source of bioactive compounds with antioxidant and anti-inflammatory properties. However, the efficient extraction of these compounds depends on optimized process conditions and suitable extraction techniques that ensure high yield with the compound's stability. Conventional extraction methods often expose compounds to heat and an oxidative environment, which can degrade sensitive molecules. To address this, this study evaluated the extraction efficiency of these bioactive compounds using a hydroethanolic solvent through vacuum-assisted extraction (VAE) method. For comparison purposes, the bed-stirred extraction (BSE) was also performed. A design of experiments was applied to optimize the process, identifying the solid-solvent ratio (1:150, g/mL) as a key factor for both extraction methods, with similar optimal ethanol concentrations of around 80% for BSE and VAE methods. VAE significantly increased the recovery of total phenolic and flavonoid compounds by 37% and 48%, respectively, and four times the vitamin content compared to BSE. This is due to the enhanced penetration of solvents and the protection of bioactive compounds from oxidation under vacuum conditions. VAE extracts exhibited stronger free radical scavenging in DPPH and ABTS assays (23 ± 1 and 28 ± 1 µg/mL, respectively), with IC₅₀ values up to 75% lower than BSE extracts, indicating higher oxidative stress reduction potential near the BHT reference. The VAE extract presented anti-inflammatory activity (measured by lipoxygenase inhibition assay), with an IC₅₀ of 52 ± 1 µg/mL near the acetylsalicylic acid (43.3 ± 2.4 µg/mL). The enhanced bioactivity of VAE extracts is attributed to their phytochemical profile, which has higher concentrations of phenolic compounds and vitamins.