After reaction (3 min), 300 mL of
Na2CO3 was added and the mixture kept at room temperature for
2 h. The absorbance was then read at 765 nm on a UVevisible
spectrophotometer (Shimadzu, UV-1800, Japan). A standard curve
was constructed to quantify phenolic compounds, using gallic
acid at concentrations of 0e0.50 mg/mL. The results are presented
in mg gallic acid/100 g of fresh sample