# Auricularia auricula Polysaccharide Modulates Rheological, Thermal, and Structural Properties of Wheat Gluten via Selective Regulation of Glutenin and Gliadin

## TL;DR

Auricularia auricula Polysaccharide improves wheat gluten's structure and stability by altering glutenin and gliadin properties.

## Contribution

This study reveals how AAP selectively modulates glutenin and gliadin to enhance gluten's rheological and thermal properties.

## Key findings

- AAP increased storage and loss modulus of gluten, glutenin, and gliadin, forming compact protein networks.
- AAP enhanced glutenin's thermal stability and disulfide bonds but reduced these in gliadin.
- AAP improved glutenin's structural order while reducing gliadin's, confirmed by secondary structure and microscopy analyses.

## Abstract

This study investigated the effects of Auricularia auricula Polysaccharide (AAP) concentrations on the rheological and thermal properties of gluten and its subunit components. We used multiple techniques, including dynamic rheology, differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FT-IR), free thiol group analysis, and scanning electron microscopy (SEM). The results revealed that AAP increased the storage (G′) and loss (G″) modulus of gluten, glutenin, and gliadin, promoting compact elastic protein networks. DSC and free thiol group analysis demonstrated that AAP enhanced thermal stability and disulfide bond cross-linking in gluten and glutenin, but reduced thermostability and inhibited disulfide formation in gliadin. Secondary structure analysis showed 31.93% and 17.72% increases in α-helix and β-sheet content, respectively, in glutenin at 8% AAP, thereby enhancing the orderliness of the gluten structure and improving structural rigidity, while reducing gliadin’s structural order. Microscopy confirmed AAP narrowed gluten matrix pores, forming uniform honeycomb structures (though high concentrations caused disruption). In summary, AAP primarily stabilizes gluten conformation by modulating glutenin structure, thereby enhancing rheological and thermal properties.