Submitted to: Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/29/2012
Publication Date: 6/1/2013
Citation: Melendez-Martinez, A.J., Stinco, C.M., Liu, C., Wang, X. 2013. A simple HPLC method for the comprehensive analysis of cis/trans (Z/E) geometrical isomers of carotenoids for nutritional studies. Food Chemistry. 138(2-3):1341-1350. Interpretive Summary: Carotenoids are antioxidant pigments found in plants and other organisms that go through photosynthesis. People consuming diets rich in carotenoids from natural foods live longer, healthier lives. There are more than 600 identified carotenoids, and in the past it has been difficult and time consuming to analyze them all for a single study as they can’t all be detected simultaneously with the same machinery and procedure. In order to expand our knowledge of carotenoid metabolism and their biological role, in this study we developed a method to detect the highest number of carotenoids in a human blood sample over the shortest amount of time. Up to 48 of the main human carotenoids were separated, and recorded in one hours’ time using High-Performance Liquid Chromatography (HPLC). This method will greatly help the analysis of carotenoids in human blood or animal studies in the future.
Technical Abstract: Geometrical isomers of carotenoids behave differently in aspects like stability towards oxidants, bioavailability, vitamin A activity and specificity for enzymes. The availability of HPLC methods for their detailed profiling is therefore advisable to expand our knowledge on their metabolism and biological role. In this paper the development of a methodology to determine the highest number of geometrical isomers of major carotenoids in humans (phytoene, phytofluene, lutein, zeaxanthin, b-cryptoxanthin, a-carotene, b-carotene and lycopene) is described. To assess its usefulness with biological samples both postprandial human plasma and lung samples from ferrets were analyzed. Up to 48 isomers of the main human carotenoids were separated in 62 min. This is to the best of our knowledge the report of the highest number of carotenoid geometrical isomers separated with a HPLC method. Twenty-six different carotenoid isomers were readily detected in the biological samples.