Valorization of mangaba residue (Hancornia speciosa Gomes) for polygalacturonase production from Aspergillus niger IOC 4003 and fabrication of active chitosan films

The present study proposes to obtain polygalacturonases, antioxidant compounds, and active chitosan films from a valorization scheme of mangaba residue. After extraction with ethanolic solution, the mangaba residue was used as a substrate for solid state fermentation (SSF) of Aspergillus niger IOC 4003, which obtained 76.32 U g −1 for polygalacturonase after 96 h cultivation. The previous step of solvent extraction increased the enzyme productivity and allowed the production of pH-tolerant polygalacturonase in SSF experiments. The addition of polygalacturosanase under 1.0 U mL −1 enabled the reduction of turbidity (34%) and viscosity (11%) of mangaba juice compared to enzyme-free condition. Solid residue from the SSF step was used in the extraction of alkaline lignin with sodium hydroxide, which allowed the recovery of 21.82% of the initial Klason lignin content. Supplementation of chitosan films with ethanolic extract and 0.1% (w v −1 ) alkaline lignin changed the values of antioxidant activity (increase of 86.5% and 45.4%) and permeability (reduction of 43.2% and 2.3%).