Optimization of an extraction method for the simultaneous quantification of sixteen polyphenols in thirty-one pulse samples by using HPLC-MS/MS dynamic-MRM triple quadrupole.

Pulses are an important source of proteins, carbohydrates, and dietary fibre, and also contain polyphenols, which are bioactive compounds with antioxidant activity. A new analytical method that uses high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was developed for the quantification of sixteen polyphenols in thirty-one pulse varieties. Different extraction procedures were tested (acidic hydrolysis, alkaline hydrolysis and extraction without hydrolysis), and acidic hydrolysis at pH 2, extraction temperature of 20 °C and extraction time of 2 h was proven to be the best in terms of recovery percentages (99.7-107.6%). The highest polyphenol levels were found in beans, particularly black beans (459 mg kg) and ruviotto beans (189 mg kg); significant levels of polyphenols were also observed in lentils, particularly black lentils (137 mg kg) and quality gold lentils (132 mg kg). This study provides new information about legume polyphenols, offering reasons to promote legumes as part of a healthy diet.