posted on 2022-12-21, 20:07authored byNikita
P. Bacalzo, Garret Couture, Ye Chen, Juan J. Castillo, Katherine M. Phillips, Naomi K. Fukagawa, Carlito B. Lebrilla
Carbohydrates are the most abundant biomolecules in nature,
and
specifically, polysaccharides are present in almost all plants and
fungi. Due to their compositional diversity, polysaccharide analysis
remains challenging. Compared to other biomolecules, high-throughput
analysis for carbohydrates has yet to be developed. To address this
gap in analytical science, we have developed a multiplexed, high-throughput,
and quantitative approach for polysaccharide analysis in foods. Specifically,
polysaccharides were depolymerized using a nonenzymatic chemical digestion
process followed by oligosaccharide fingerprinting using high performance
liquid chromatography–quadrupole time-of-flight mass spectrometry
(HPLC-QTOF-MS). Both label-free relative quantitation and absolute
quantitation were done based on the abundances of oligosaccharides
produced. Method validation included evaluating recovery for a range
of polysaccharide standards and a breakfast cereal standard reference
material. Nine polysaccharides (starch, cellulose, β-glucan,
mannan, galactan, arabinan, xylan, xyloglucan, chitin) were successfully
quantitated with sufficient accuracy (5–25% bias) and high
reproducibility (2–15% CV). Additionally, the method was used
to identify and quantitate polysaccharides from a diverse sample set
of food samples. Absolute concentrations of nine polysaccharides from
apples and onions were obtained using an external calibration curve,
where varietal differences were observed in some of the samples. The
methodology developed in this study will provide complementary polysaccharide-level
information to deepen our understanding of the interactions of dietary
polysaccharides, gut microbial community, and human health.