Performance of a crude enzymatic cocktail produced by Aspergillus niger LBM 321 in the recovery of bound phenolic compounds

Abstract

Jabuticaba (Plinia cauliflora) processing generates substantial epicarp waste rich in phenolic compounds, which have antioxidant and health-promoting potential. To valorize the jabuticaba epicarps via a green biotechnological approach, we developed and optimized an enzyme extraction of phenolic compounds using a fungal cocktail produced by Aspergillus niger LBM 321. A central composite design was employed to evaluate the effects of temperature, pH, and time of extraction. The optimal conditions were 38.5 C, pH 5.34, and 10 h yielded 72.94 mg GAE 100 mL⁻¹. Under these conditions, enzymatic extraction outperformed alkaline hydrolysis (1 N NaOH, pH 9.5) and commercial enzyme extraction (Viscozyme L). UHPLC-MS/MS analysis revealed that ρ-coumaric and ferulic acids were the predominant phenolics in the fungal enzyme extracts, suggesting preferential liberation of ester-linked hydroxycinnamic acids from the cell wall matrix. FTIR spectroscopy presented enhanced C?O stretching bands after enzymatic treatment, indicating selective polysaccharide hydrolysis and release of phenolic compounds. This study demonstrates that A. niger LBM 321 enzymes offer an eco-friendly and cost-effective strategy for recovering high-value phenolics from jabuticaba epicarps. By converting waste into functional ingredients, this approach supports a circular-economy model and aligns with consumer demands for natural, sustainable food additives.