Effect of physical and thermal processing upon benzylglucosinolate content in tubers of the B rassicaceae maca ( L epidium meyenii ) using a novel rapid analytical technique

Summary Benzylglucosinolate ( BG ) was extracted by 70% methanol from maca and purified on acidic alumina column and semi‐preparative C osmosil cholester column. The purified sample was verified as BG by electrospray ionisation mass spectrometry ( ESI ‐ MS ) and nuclear magnetic resonance spectra. The purity was 98.3% as determined by HPLC ‐ MS . BG content of maca was quantified using external standard method by HPLC . Effect of physical and thermal processing on BG content of maca was investigated. When maca was steamed for 5 min before shredding, no significant difference of BG content was observed during postshredding time, while raw maca lost 57.2% of BG in 24 h. Steamed maca showed no significant loss of BG after drying at the temperature from 20 to 80 °C in 24 h. Thermal degradation was described by the first‐order kinetics–Arrhenius equation for BG in the temperature range of 90–100 °C.