Pea protein isolate-gum Arabic Maillard conjugates improves physical and oxidative stability of oil-in-water emulsions

Abstract

The present work investigated the impact of incubation time (0, 1, 3, and 5 day) on the properties and functionalities of conjugates formed between pea protein isolate (PPI) and gum Arabic (GA). The participation of both 11S and 7S to form conjugates with GA was proved by SDS-PAGE. The degree of conjugation reaction of conjugated was characterized by measuring the formation of Maillard reaction products, the loss of free amino groups, and color changes. The results suggested that PPI intimately incorporated into GA after 1 day incubation, giving a non-homogeneous microstructure with a reduction of nearly 18% available free amino and an increase of relative solubility to 15.5%. Additionally, emulsions prepared by PPI-GA conjugates showed smaller particle size, higher surface charge, and stronger steric hindrance to stabilize the emulsion droplets against environmental stresses and lipid oxidation. The findings provide a practical means to improve the functionality of pea proteins.

Keywords: Antioxidants; Conjugates; Emulsions; Glycation; Maillard reaction; Plant protein; Polysaccharide.