Fungal-Assisted Extraction-SSF of Phenolic Compounds from Moringa oleifera and Its Effects on Antimicrobial and Antioxidant Properties

This study evaluates fungal-assisted extraction by solid-state fermentation (FAE-SSF) as a green alternative for recovering phenolic compounds from Moringa oleifera leaves and compares it with conventional maceration, focusing on their effects on antimicrobial and antioxidant properties. FAE-SSF was carried out using Aspergillus niger, and phenolic compounds were quantified as total polyphenols (hydrolysable and condensed tannins), followed by purification and characterization by HPLC-ESI-MS. Biological activities were assessed through antibacterial, antifungal, and DPPH assays. FAE-SSF increased total phenolic content to 20.3 ± 1.7 mg TP/g dry basis at 96 h, representing a 1.53-fold increase compared to maceration (13.3 ± 0.3 mg TP/g db at 24 h). However, maceration showed higher productivity due to shorter extraction time. FAE-SSF extracts exhibited improved antibacterial activity against Staphylococcus aureus, while no activity was observed against Shigella sp., and antifungal activity was lower compared to maceration. Antioxidant activity was also reduced in FAE-SSF extracts (39 ± 7%) compared to maceration (71 ± 4%). HPLC-ESI-MS analysis revealed that maceration preserved a greater diversity of phenolic compounds, whereas FAE-SSF induced biotransformation and reduction of key flavonoids. These results indicate that FAE-SSF enhances phenolic recovery but alters chemical composition and bioactivity, highlighting the importance of process optimization depending on the desired functional properties.