Quality Evaluation of Lepidium meyenii (Maca) Based on HPLC and LC-MS Analysis of its Glucosinolates from Roots

In order to evaluate the quality of maca samples, 15 batches of maca hypocotyls from different geographical origins were analyzed by using HPLC and liquid chromatography tandem mass spectrometry (LC-MS). Their glucosinolates (GLs) were identified, profiled, and quantified. Three aromatic GLs, glucosinalbin (GSB), glucotropaeolin (GTL), and glucolimnanthin (GLH), were identified from maca roots. It was found that the HPLC profiles of maca samples showed a similar qualitative pattern except for some differences in their contents. The amount ranges (μmol g−1, DW) of GSB, GTL, and GLH were 2.62–5.55, 12.99–57.12, and 3.15–12.12, respectively. Furthermore, a HCA (hierarchical clustering analysis) was used to classify the quality of maca samples according to their cultivated sources and GLs contents. The results showed that the combination of GSB, GTL, and GLH could be a marker for accurate determination and quality control of maca samples. It was concluded that the multi-component analysis in combination with HCA could be a supplement to assess the quality of maca materials.