Designing W 1/O/W 2 double emulsions stabilized by protein–polysaccharide complexes for producing edible films: Rheological, mechanical and water vapour properties

Abstract

Rheological properties and the droplet mean volume-surface diameter of water-in-oil-in-water double emulsions E LMP–WPI and E CMC–WPI, stabilized with low-methoxyl pectin (LMP)–whey protein isolate (WPI) or sodium carboxymethylcellulose (CMC)–WPI complexes were determined. E LMP–WPI emulsions showed smaller droplet diameter (2.47 μm) than E CMC–WPI emulsions (10.68 μm), and higher values of apparent viscosity, storage modulus and loss modulus. Microstructure and mechanical properties of the F LMP–WPI and F CMC–WPI films were affected by the type of the stabilizing biopolymer complex used in the formulation of the E LMP–WPI and E CMC–WPI double emulsions from which were prepared. The F LMP–WPI films microstructure consisted of a biopolymer mainframe relatively compact, interrupted by small emulsion droplets. The F CMC–WPI film mainframe had an open and oriented structure, in which relatively large emulsion droplets were packed. F LMP–WPI films presented higher values of transparency, tensile strength and Young’s modulus, but lower elongation percentage and comparable water vapour permeability than F LMP–WPI films.