Effective clean-up and Ultra High-Performance Liquid Chromatography-Tandem Mass Spectrometry for isoflavone determination in legumes

Legumes are an excellent source of macronutrients and phytochemicals as isoflavones. The aim of this work was to develop a new analytical method for determining five isoflavone compounds, three of which are aglycons, namely daidzein, genistein, biochanin A, and two of which, daidzin and genistin, are glycosilated, in lentils and other pulses, using an effective clean-up system and UHPLC–MS/MS (triple quadrupole) method. The recoveries obtained by spiking the lentil samples with a standard mixture of isoflavones at three levels of fortification (5, 25 and 100 lg kg1) were in the range of 54.4–111.1%, 68.6–91.1%, and 84.4–114%, respectively. The method was applied to analyse 48 lentil samples from central Italy and pulses for determining the isoflavone content, which was found to range from 1.1 to 95.6 lg kg1.