Detection of Common Vetch (Vicia sativa L.) in Lentil (Lens culinaris L.) using unique chemical fingerprint markers

Detection of adulteration of split red lentil (Lens culinaris L.) seeds with low level addition of split common vetch (Vicia sativa L.) is hampered by a lack of reliable detection methods. An analytical method was developed using high performance liquid chromatography with diode array detection (HPLC-DAD) based on two unique chemical markers found in common vetch: ß-cyanoalanine (BCA) and γ-glutamyl-ß-cyanoalanine (GCA). These two markers were present in samples of common vetch seed grown in Canada and Serbia. Authentic lentil samples grown in Canada, Australia, USA, Turkey, Syria, and Morocco had no detectable levels of these chemical markers. Commercial lentil samples for export from lentil processing plants in Saskatchewan, Canada, also had no detectable levels of GCA and BCA. The presence of vetch in intentionally adulterated lentil samples could be determined via chemical markers with a detection limit of 5% (w/w). The proposed method is a simple sample extraction and rapid HPLC analysis that could be widely used to detect intentional adulteration of lentils with common vetch.