Chemical and genetic characterization of Maca (Lepidium meyenii)

Maca (Lepidium meyenii synonym Lepidium peruvianum) is a tuber grown in Peru and China at elevations above 4,000 feet which has become popular throughout the world. Raw samples were collected in Peru and China and compared with commercially prepared products which have been ground, extruded, and gelatinized. The raw samples were classified on collection as white, yellow, red, or black based on their appearance and age. With hundreds of samples, samples were initially analyzed by flow injection high resolution mass spectrometry (FIHRMS) to obtain spectral fingerprints. Principal component analysis of the fingerprints revealed 3 distinct clusters corresponding to the 3 sample types described above. Representative samples were selected from each cluster and sent for next generation sequencing and subjected to metabolomic analysis by ultra-high-performance liquid chromatography coupled to high resolution accurate mass/tandem mass spectrometry (UHPLC-HRAM/MSn). All samples DNA profiles were found to correspond to those for Lepidum meyenii in the database. Metabolomics revealed the presence of numerous phenolic and amide compounds which varied in correspondence with their cluster. Chemical composition differences between the black, red, yellow, and white maca samples were observed.