Compound treatment of thiolated citrus high-methoxyl pectin and sodium phosphate dibasic anhydrous improved gluten network structure

[Display omitted] •Thiolated pectin treatment improved the strength of gluten protein.•A gel-like network was observed in thiolated pectin and Na2HPO4 treated gluten by SEM.•Thiolated pectin and Na2HPO4 compound treatment induced aggregation of gluten protein.•FT-IR spectra indicated thiolated pectin compound Na2HPO4 improved gluten stability. The effects of pectin or thiolated pectin alone and combined with sodium phosphate dibasic anhydrous (Na2HPO4) on the performances of gluten were studied. Results showed that compared with pectin treated gluten, the thiols of thiolated pectin treated gluten increased by 8.7 times. Analysis of the extensibility and rheological properties revealed that pectin reduced gluten strength, whereas thiolated pectin improved the strength and viscoelasticity of gluten, especially with the assistance of Na2HPO4. Furthermore, thiolated pectin and Na2HPO4 compound increased enthalpy (ΔH, from 150.42 to 168.60 J/g) and decreased Imax (from 5255.33 to 2775.33) markedly, indicating gluten aggregation. The highest β-sheet (76.47%) and the lowest α-helix/β-sheet ratio (0.11) were found in gluten treated with thiolated pectin and Na2HPO4 and suggested gluten stability was enhanced. SEM observation confirmed that thiolated pectin and Na2HPO4 compound strengthened the gluten structure. These results are of great significance for the supplementation of pectin in wheat products.