2.4.2. Determination of Total Flavonoid Content (TFC)

The TFC of the pear sample was measured by modifying the aluminum chloride method of Stavrou et al. [13]. The sample extracts (80 µL), 2% aluminum chloride (80 µL, w/v, diluted with ethanol) and sodium acetate solution (120 µL, 50 g/L) were mixed in a 96-well plate and then incubated in the dark at room temperature for 60 min. The absorbance was measured at 440 nm in a microplate reader. The calculation of TFC of each sample was based on the standard curve of quercetin (0 to 50 µg/mL) and the result was expressed as mg of quercetin equivalent per g (mg QE/g DW) of dry weight.