0.5 mL of 8% (w/v) of vanillin was added, mixed with 5 mL
concentrated H2SO4 (72%) and incubated in a waterbath at
60 ◦C for 15 min and then cooled on ice to room temperature
prior to measurement of absorbance (560 nm). Aescin was
used as the standard for a calibration curve and the results
were expressed as mg of aescin equivalents per gram of sample
(mg Aes/g).