Analysis and metabolomics of carotenoids

Abstract Carotenoids (carotenes and xanthophylls) are C14 isoprenoid pigments naturally synthesized by plants, algae, yeast, fungi, and photosynthetic bacteria. Their importance in human and animal health plus their key role in plant metabolism, have led to a growing number of analytical methods for qualitative and quantitative determinations. Liquid chromatography (LC) coupled with absorbance detectors (UV, Vis, and PDA) and/or mass spectrometers (MSs) are currently the most common instrumental methods for carotenoid and apocarotenoid analysis. Supercritical fluid chromatography (SFC) and comprehensive two-dimensional (2D) LC (LC × LC) are interesting alternatives to conventional LC separations, as they show the extra capability to resolve complex mixtures of lipidic nature, including carotenoid isomers. However, these technologies require more specialized and expensive instruments and longer analytical times, nearly double than LC. On top of this, in the past decade, carotenoid analysis has moved from classical approaches to more modern and innovative solutions, as the high-throughput metabolomics. In this context, high-resolution mass spectrometry (HRMS) outstands out for its high-resolution and high mass accuracy.