Multi-Glycomic Characterization of Fiber from AOAC Methods Defines the Carbohydrate Structures

Area of Science:

• Nutritional Science
• Analytical Chemistry
• Microbiology

Background:

• Dietary fiber is vital for health and significantly influences the gut microbiome.
• Fiber's impact on the microbiome is structure-specific, but current analysis methods lack this detail.
• Understanding fiber structure is key to unlocking its full health potential.

Purpose of the Study:

• To develop a novel analytical pipeline for detailed dietary fiber structural analysis.
• To characterize soluble and insoluble fiber fractions from oats and potato starch.
• To bridge the gap between traditional fiber measurements and their structural components.

Main Methods:

• Utilized rapid-throughput Liquid Chromatography-Mass Spectrometry (LC-MS) methods.
• Developed a pipeline to determine monosaccharide, glycosidic linkage, and free saccharide composition.
• Applied two Association of Official Analytical Chemists (AOAC) methods (991.43 and 2017.16) for comparison.

Main Results:

• Oats showed consistent fiber composition across both AOAC methods, identifying β-glucan, arabinoxylan, xyloglucan, and mannan.
• Potato starch yielded different results for soluble fiber fractions between AOAC methods due to resistant starch.
• The novel pipeline successfully detailed complex fiber structures while maintaining classical soluble/insoluble fiber data.

Conclusions:

• The developed LC-MS pipeline provides detailed structural insights into dietary fiber.
• This analytical framework can link gravimetric fiber data to specific structures.
• Findings will advance gut microbiome and clinical nutrition research by providing precise fiber information.