Determination of the Concentration of lycopene in Tomato by using Absorption Spectroscopy
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Date
2014-06
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Addis Ababa University
Abstract
In this thesis we report the measurement of optical properties via the molar absorption
coefficient and refractive index of Lycopene. The pigment of Lycopene was extracted from
raw tomato and/or tomato paste using 50:50 Acetone−Petroleum ether solutions and
washed with Sodium chloride and Patassium carbonate. Lycopene was separated from
this mixture through Column chromatography and the use of Acetone and Hexane. Five
solutions of Lycopene in Hexane were prepared with different concentration for Uv−Vis
spectroscopic analysis and a very good correlation coefficient 0.998 was found, thereby the
average Molar absorption coefficient was calculated as 168556 L/mol× cm. For 150 grams
of raw tomato; the amount of Lycopene was measured as 7.2 mg and 7.5 mg for sample of
Genesis Farms/Debre Zeit and Ambo Timer Agro Industry/Ambo, respectively. Whereas,
the average content of Lycopene was measured as 8.62 mg (for Merti/Ethiopia) and 8.76
mg (for Meysu/Turkey) for each of 15 grams tomato paste. The average calculated amount
of all−trans−Lycopene was more than 85 percent. The refractive index of Lycopene was
measured as 1.536 with standard error of the mean and variance of significance (P < 0.05).
Key words: Lycopene, Column chromatography, Uv−Vis spectroscopy, Absorbance, Refractive index
Description
Keywords
Lycopene; Column chromatography; Uv−Vis spectroscopy;Absorbance;Refractive index.