Designing W1/O/W2 double emulsions stabilized by protein–polysaccharide complexes for producing edible films: Rheological, mechanical and water vapour properties

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