Polysaccharide identification through oligosaccharide fingerprinting

The identification of polysaccharide structures in complex samples remains a unique challenge complicated by the lack of specific tools for polymeric mixtures. In this work, we present a method that depolymerizes polysaccharides to generate diagnostic oligosaccharide markers that are then analyzed by high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (HPLC-QTOF MS). Rapid identification of food polysaccharides was performed by aligning the identified oligosaccharides with a library of oligosaccharide markers generated from standard polysaccharides. Measurements of standard and food polysaccharides were performed to obtain the contributions of the identified polysaccharides using percent peak coverage and angle cosine methods. The method was validated using a synthetic mixture of standard polysaccharides while the reproducibility was confirmed with experimental triplicates of butternut squash samples, where standard deviation was less than 3% for the relative abundance of oligosaccharides. The method was further employed to examine diverse set of food samples.