Simultaneous spectrophotometric determination of lycopene and beta-carotene concentrations in carotenoid mixtures of the extracts from tomatoes,papaya and orange juice

A simple and inexpensive spectrophotometric equation model for the simultaneous determination of lycopene and β-carotene concentrations in a mixture of carotenoids is proposed. lycopene could be exclusively determined (with the relative accuracy of more than 95%) using the absorbance data at 502 nm. because quantifying the β-carotene concentration in a ccarotenoid minture using the sole absorbance at 450 nm is prone to error,an equation to determine the concentration of this compound from the absorbances data at two wavelengths was modeled. using the modeled equations to re-check the molar absorptivity of lycopene at 472 nm,the value obtained was about 98% close to the value reported in literature. the relative accuracy of the predicted concentrations of two carotenoids using the modeled equations is a function of the ratio of these carotenoids in the samples.