Quantification of Lycopene from Tomatoes and Watermelons by Using Beer-Lambert Principle
Red tomatoes and red-fleshed watermelons contain a high level of lycopene. It is well known that lycopene is precursor to vitamin A. In Uganda, and East Africa in general, there are so many tomato and watermelon varieties with little information on their lycopene content. However, no study has been done to estimate the quantity of lycopene in fresh tomatoes and watermelons in Uganda. The objective of this study was to quantify lycopene by using Beer-Lambert Principle. The varieties were bought from Nakulabye market in Kampala, and extracted by using solvent system of acetone/ethanol/ hexane (5ml/5ml/10ml). Stirring on ice was done for 15 minutes. 3 ml of deionized water was added after shaking. Samples were shaken for 5 minutes on ice and then left at room temperature for 5 minutes to allow the separation of phases. The lycopene layer were then separated and scanned in UV-VIS spectrophotometer. The results showed that the lycopene concentration ranged from 27 μg/g to 115 μg/g with % relative error ranged from 2.86 to 3.14, the standard error ranged from ± 0.013to ± 0.015,and standard deviation ranged from 7.38 to 29.5. Both watermelons and tomato varieties contain the appreciable quantities of lycopene which is the significant nutrient for human body in daily life.
Shi J. and Maguer M. “Lycopene in Tomatoes: Chemical and Physical Properties Affected by Food Processing”. Journal of Critical Reviews in Food Science and Nutrition, vol. 40(1), pp. 1-42, Jan. 2000.
Gerster H. “The potential Role of Lycopene for Human Health”. Journal of American Coll Nutrition, vol. 16(2), pp. 109-126, 1997.
Kun Y., Lule U. S. and Lin D. X. “Lycopene: Its Properties and Relationship to Human Health”. Journal of Food Review International, vol. 22(4), pp. 309-333, July 2006.
Everson K.M., Pharm D and McQueen C.E. “Lycopene for Prevention and Treatment of Prostate Cancer”. American Journal of Health-System Pharmacy, vol. 61(15), pp. 1563-1568, 2004.
Kawuma M. “Sugar as a Potential Vehicle for Vitamin A Fortification: Experience from Kamuli District in Uganda”. Journal of Africa Health Science, vol. 2(1), pp. 11-15, 2002.
Hackett M.M., Schwartz S.J., Lee J.H. and Francis D. “Thermal Stability and Isomerization of Lycopene in Tomato Oleoresins from Different Varieties”. Journal of Food Science, vol. 69(7), pp. 536-541, 2004.
Ravelo-Perez L.M., Herandez-Borges J., Rodriguez-Delgado M.A. and Borges-Miquel T. “Spectrophotometrical Analysis of Lycopene in Tomatoes and Watermelons: A Practical Class”. Journal of the Chemical Educator, vol. 13 (1), pp. 1-4, 2007.
R.E. Wrolstad (2005). F.2.2. Detection and Measurement of Carotenoids by UV/VIS Spectrophotometry. Handbook of Food Analytical Chemistry, Volume1: water, protein, enzymes, lipids and carbohydrates [Online]. Available:
Bicanic D., Swarts J., Fogliano V., Grazian G., Luterotti S. and Piani G. “Quantification of Lycopene in Tomato Products: Comparing the Performances of a Newly Proposed Direct Photo Thermal Method and HPLC”. Journal of the Science of Food and Agriculture, vol. 85(7), pp. 1149- 1153, Feb 2005.
Mayeaux M., Xu Z., King J.M. and Prinyawiwatkul W. “Effects of Cooking Conditions on the Lycopene Content in Tomatoes”. Journal of Food Science, vol. 71(8), pp. 461-464, October 2006.
Gautier H., Diakou-Verdin V., Bénard C., Reich M., Buret M., Bourgaud F., Poëssel J.L., Caris-Veyrat C. and Génard M. “How does a Tomato Quality (Sugar, Acid and Nutritional Quality) Vary with Ripening Stage, Temperature and Irradiance?”. Journal of Agricultural and Food Chemistry, vol. 56(4), pp. 1241-1250, Feb 2008.
- There are currently no refbacks.