Multiple reaction monitoring for identification and quantification of oligosaccharides in legumes using a triple quadrupole mass spectrometer

Raffinose family oligosaccharides are non-digestible compounds considered as dietary prebiotics with healthrelated properties. Hence, it is important to develop highly specific methods for their determination. An analytical method is developed in this study for oligosaccharide identification and quantification using liquid chromatography-tandem mass spectrometry equipped with a triple quadrupole analyser operating in Multiple Reaction Monitoring mode. Raffinose, stachyose and verbascose are separated in a 10-minute run and the method is validated over a broad concentration range, showing good linearity, accuracy, precision and high sensitivity. A low-cost, short eco-friendly procedure for oligosaccharide extraction from legumes, with a high recovery rate extraction, good repeatability and reproducibility is also proposed. No plant-matrix effects were demonstrated. The method applied to the screening of 28 different legumes revealed species-related traits for oligosaccharide distribution, highlighting Pisum sativum (9.22 g/100 g) as the richest source of these prebiotics and its suitability as a functional food ingredient.

Automated summary

This study developed a highly specific analytical method for the identification and quantification of raffinose family oligosaccharides using liquid chromatography-tandem mass spectrometry. A low-cost and eco-friendly procedure for oligosaccharide extraction from legumes was also proposed, with good precision and repeatability. The method revealed species-related traits for oligosaccharide distribution among 28 different legumes, emphasizing peas as the richest source of prebiotics.