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.
