Chromatographic Considerations and Maltitol Interference in Dietary Fiber Analysis

AOAC 2017.16 and AOAC 2022.01 are CODEX Type I methods for total dietary fiber (TDF) that integrate enzymatic-gravimetric steps with HPLC quantification of low molecular weight soluble dietary fiber (SDFS). As implementation expands, chromatography-related limitations and matrix-specific interferences can affect SDFS determination.

To evaluate performance of AOAC-recommended and alternative HPLC columns for DP2/DP3 boundary assignment across a broad carbohydrate set, and to investigate maltitol-associated interference leading to apparent SDFS overestimation in starch-containing matrices.

Seventy-four carbohydrate standards (including oligosaccharides, polyols, and sugar alcohols) were analyzed in duplicate across five HPLC column configurations under AOAC 2017.16/2022.01 and AOAC 2009.01/2011.25 conditions. Column performance was scored by correct peak-area assignment relative to the maltose demarcation.Maltitol interference was assessed using food products formulated with/without maltitol and mixtures of maltitol (and other polyols) with wheat starch or wheat flour using scaled AOAC 2017.16 and AOAC 2001.03 procedures.

Across 74 analytes, SugarPak (Waters) provided the highest overall assignment accuracy, with a two-column series configuration scoring highest.Maltitol alone could be excluded by adjusting the DP2/DP3 demarcation; however, maltitol combined with glucose-based polymers produced additional peak area in the SDFS region, yielding up to ∼8% apparent SDFS overestimation in wheat starch mixtures.

Chromatographic selection materially affects DP2/DP3 assignment for SDFS quantification.Maltitol can cause matrix-dependent artifactual SDFS in starch-containing test materials, suggesting formation of low-molecular-weight species during enzymatic processing.Guidance on column equivalency would strengthen AOAC dietary fiber methodology and further work is warranted to further investigate maltitol interaction with glucose-based polymers during TDF analysis.