Determination of quantity of Lutein in vegetables

Abstract

Lutein, a yellow-colored macular carotenoid, has been widely known for its beneficial effects to human health. Since Human beings do not present the ability to synthesize carotenoids, lutein being among them, these must be supplied by a balanced consumption of fruits and vegetables. The objective of the current research was to evaluate the concentration of lutein presented in vegetables commonly consumed in the State of Minas Gerais. The results of this study provide data so the population can know which food presents the highest sources of this carotenoid. The extraction of the pigment was carried out in acetone, ethanol, hexane and tetrahydrofurane solutions for 24 hours. After the extraction, a saponification in 10% ethanolic KOH occurred so the removal of impurities such as clorophyl and lipidic acids could be obtained. The quantity of lutein in the vegetables was determined by spectrophotometric measures, which was later confirmed by HPLC. From the results obtained, it was observed that acetone was the most effective solvent to extract the analysed pigment whereas hexane should not be used in the extraction of fresh vegetables. Vegetables such as cabbage, rucola, mustard, chard, spinach, azedinho and broccoli constitute a rich source of Lutein. Moreover, it is important to emphasize the high concentration of this carotenoid found in lobrobô, also known as ora-pro-nobis, as well as in serralha, chicory and tannia. However, those former mentioned vegetables are not commonly found in the diets consumed by the population of the State of Minas Gerais.