2.3.3 Metabolomic analyses
Quinoa roots stored at -80 °C were used for metabolomic analysis. Amount of 100 mg of ground root tissue was placed in an Eppendorf tube, 500 μL of 80% v/v methanol in water was added, vortexed and shaken, left to stand in an ice bath for 5 min, then centrifuged at 15,000 g at 4°C for 20 min. Supernatant was collected, diluted with mass spectrometry-grade water to reach 53% v/v methanol and analyzed by LC-MS (Want et al., 2013).