Exploring Flavonoids and Citric Acid Extraction Yields from Lemon Peels Across Glucanase, Cellulase, and Pectinase Enzymes

Lemon peel, which contains a wide variety of antioxidant compounds and biopolymers, is an interesting byproduct for valorization. In this study, pectin and cellulose were obtained from lemon peel with 36% and 23% extraction yields. Meanwhile, when evaluating the extraction of secondary metabolites using various enzymes, it was found that their concentrations increased the most in the case of pectin methylesterase, by up to 21.7% for eriocitrin, although the solid residue was not affected spectroscopically by the enzymatic activity. In contrast, enzyme mixes with β-glucosidase activity showed no presence of the O-glycosylated flavonoids, suggesting their hydrolysis into the aglycones.