Low-cost extraction of multifaceted biological compounds from citrus waste using enzymes from Aspergillus Niger LBM 134
Gabriela Verónica Díaz, Romina Olga Coniglio, Laura Ester Ortellado, Pedro Darío Zapata, M. Alejandra Martínez, María Isabel Fonseca
Abstract
Abstract Agricultural industries search for biotechnological alternatives for waste management as they mean a significant concern and environmental challenge. More importantly, within a circular economy concept, such secondary substrates can be used to produce value-added compounds. This work is aimed at obtaining bioactive compounds from citrus waste by using a homemade enzymatic cocktail from Aspergillus niger LBM 134. The fungal enzymes were produced using raw sugarcane bagasse as substrate, which increased the ecological sustainability and the cost-effectiveness of the bioprocess. As the most relevant enzyme of this cocktail, a β-glucosidase showed to optimally act at 50 °C, retaining up to 70% of residual activity after 72 h. By means of an optimized enzyme-assisted extraction, the crude enzymatic cocktail produced was efficiently employed to extract the phenolics hesperetin, quinic, p -coumaric, and gallic acid, and the bioactive amino acid tryptophan from citrus waste. These assays yielded approximately 112% and 30% of phenolic compounds over alkaline conventional and commercial enzyme extraction methods, respectively. Graphical Abstract