The β-carotene content was determined using the Shimadzu UV Mini-1240 UV-VIS spectrometer following the methods of Harborne (1973) as cited by Lakra et al. (2018) with acetone: hexane (3:7) as the extraction solvent and β-carotene (Fluka BioChemika 22040) solutions as standard. Absorbance reading was done at 440 nm against a blank. The β-carotene and Vitamin A contents were calculated as follows, wherein 1 I.U. of Vitamin A is equivalent to 0.6 µg β-carotene:
Lycopene content was also determined using the Shimadzu UV Mini-1240 UV-VIS spectrometer following the methods of Fish et al. (2002) (link) using hexane:ethanol: acetone (1:1:2) as the extracting solvent. The absorbance reading of the non-aqueous portion was read at 503nm against a blank and the lycopene content was calculated using the formula:
Where 537 g/mole = molecular weight of lycopene, 8 mL = volume of extracting solvent, 0.55 = volume ratio of the upper layer to the extracting solvent, 0.10 g = weight of sample, 172 mM -1 = extraction coefficient for lycopene in hexane
Lycopene content was also determined using the Shimadzu UV Mini-1240 UV-VIS spectrometer following the methods of Fish et al. (2002) (link) using hexane:ethanol: acetone (1:1:2) as the extracting solvent. The absorbance reading of the non-aqueous portion was read at 503nm against a blank and the lycopene content was calculated using the formula:
Where 537 g/mole = molecular weight of lycopene, 8 mL = volume of extracting solvent, 0.55 = volume ratio of the upper layer to the extracting solvent, 0.10 g = weight of sample, 172 mM -1 = extraction coefficient for lycopene in hexane