Fifty mg powder was weighed into a 125 mL-flask, dispersed in water (1.5 mL) and ethanol (1 mL) and extracted with hexane (25 mL). After shaking (500 rpm) for 30 min at room temperature, the hexane fraction was collected, adjusted to 25 mL and absorbance read at 454 nm using a UVeVis spectrophotometer (Beckman Coulter DU-800, Fullerton, CA).
The concentration of carotenoid was evaluated with respect to the initial concentration as C/Co, where C is the carotenoid concentration at a given time and Co is the initial concentration.