Low-ester pectin effectively enhanced the thermal, rheological and structural properties of wheat dough relative to the high-ester pectin

Abstract

Studying the effects of pectin with different degree of esterification (DE) on dough properties can lay a foundation for regulating dough network structure and flour product quality through pectin. Thus, the effect of pectins with different DE on dough properties was compared. Compared with control dough, low-ester pectin (LEP) greatly improved the viscoelasticity of dough, significantly increased the enthalpy (from 1.51 to 1.75 J/g), hardness, chewiness, and the peak load (from 0.14 to 0.40 N) of dough, while decreasing the deformation (from 35.43 to 13.23 mm) of dough. Moreover, LEP significantly promoted the transformation of sulfhydryl groups to disulfide bonds (from 8.99 to 10.12 μmol/g). Compared with high-ester pectin (HEP), LEP increased β-sheet content by 34.21% and decreased fluorescence intensity from 1950.67 to 363.03, suggesting that structure stabilization of gluten was enhanced. SEM images also indicated that LEP was more conducive to maintaining the stability of dough structure. However, both LEP and HEP did not change the crystal structure of wheat starch in the dough. In summary, LEP improved dough structure more effectively, while HEP weakened dough structure. These results can provide a theoretical basis for regulating dough network structure and the quality of flour products through different pectins.