Effect of ionic strength (NaCl and CaCl2) on functional, textural and electrophoretic properties of native and acetylated gluten, gliadin and glutenin

Abstract

The main objective of this study was to determine the effects of different ionic strengths (IS) of NaCl and CaCl2 (0.2, 0.4 and 0.6 at pH=7) on the functional (water holding capacity (WHC), water absorption (WA), emulsifying activity (EA), emulsion stability (ES), textural and electrophoretical properties of native (N) and acetylated (AC) gluten, gliadin and glutenin. According to FT-IR and TNBS methods, the modification extent of wheat gliadin and glutenin were somewhat lower and higher than gluten, respectively. The results indicating that functionality AC glutenin was more than AC gluten and gliadin. NaCl and CaCl2 had negative impact on WHC, WA, EA and ES of proteins. Different IS of NaCl and CaCl2 may only alter the molecular conformation of N and AC gluten, gliadin and glutenin without having any significant effect on the molecular weights of these proteins. AC proteins had significantly higher WHC of gels compared to N proteins and also, CaCl2 could enhance the WHC and hardness of N and AC protein compared with NaCl. Hardness of AC glutenin more impressed than gliadin and gluten due to high degree acetylation.