Acid/alkali shifting of Mesona chinensis polysaccharide-whey protein isolate gels: Characterization and formation mechanism

Food Chem. 2021 Sep 1:355:129650. doi: 10.1016/j.foodchem.2021.129650. Epub 2021 Mar 23.

Abstract

In this study, structural characteristics and formation mechanism of Mesona chinensis polysaccharide (MCP)-whey protein isolate (WPI) gels including group and molecular changes, intermolecular forces, crystallinity, and moisture migration were investigated under pH shifting conditions. Results showed that MCP and WPI formed a stable gel at pH 10. The free sulfhydryl groups and surface hydrophobicity of the MCP-WPI gels increased with the increasing pH. Hydrophobic and hydrogen bond interactions were the main molecular forces involved in the MCP-WPI gels, and electrostatic interactions and disulfide bonds played a complementary role. The pH conditions evidently influenced the secondary conformational structure of MCP-WPI gels. Molecular weight and X-ray diffraction (XRD) analysis indicated the formation of a hypocrystalline complex with molecular interaction. In addition, low-field magnetometry (LF-NMR) results showed that the T2 values decreased with increasing pH, indicating that water and gel matrix had the highest interactions at pH 10.

Keywords: Characterization; Interactions; Mechanism; Mesona chinensis polysaccharide.

MeSH terms

  • Alkalies / chemistry*
  • Gels
  • Hydrogen-Ion Concentration
  • Hydrophobic and Hydrophilic Interactions
  • Lamiaceae / chemistry*
  • Polysaccharides / chemistry*
  • Rheology
  • Water / chemistry
  • Whey Proteins / chemistry*

Substances

  • Alkalies
  • Gels
  • Polysaccharides
  • Whey Proteins
  • Water