Green tea and kombucha characterization: Phenolic composition, antioxidant capacity and enzymatic inhibition potential

The present study aimed to carry out the physical-chemical, antioxidant, and enzymatic characterization of green tea and kombucha. It was observed that kombucha had lower pH, higher acidity, and solids content compared to green tea. As for the concentration of total phenolic compounds by the Folin Ciocalteu method, there was no significant difference between the beverages. In the antioxidant analysis by the DPPH assay, it was observed that both green tea and kombucha presented significant antioxidant capacity. In the TBARS analysis with the pH of the beverages neutralized, both showed a significant reduction in lipid peroxidation; however, kombucha exhibited pro-oxidant activity when evaluated in its natural form by this method. The beverages also showed significant inhibitory activity of the α-glucosidase enzyme, however, green tea presented superior inhibitory potential.