Emulsions of sunflower wax in pectin aqueous solutions: Physical characterization and stability

• Published in: Food research international Vol. 108; pp. 216 - 225
• Main Authors: Chalapud, Mayra C., Baümler, Erica R., Carelli, Amalia A.
• Format: Journal Article
• Language: English
• Published: Canada Elsevier Ltd 01.06.2018
• Subjects: Confocal microscopy; Emulsions; High-oleic sunflower wax; Low methoxyl pectin; Normal sunflower wax; Particle size distribution; Physical stability; Rheology; Emulsions; High-oleic sunflower wax; SFW; Rheology; Low methoxyl pectin; Normal sunflower wax; Confocal microscopy; Physical stability; BS; Particle size distribution; S; NE; HOE
• ISSN: 0963-9969; 1873-7145
• DOI: 10.1016/j.foodres.2018.03.053

The knowledge of the stability and physical properties of film-forming solutions is necessary for optimizing the process design of films. In order to evaluate their applicability for the production of edible films, the rheological and microstructural properties, particle size and physicochemical stability of aqueous emulsions of low methoxyl pectin and sunflower waxes from normal and high-oleic hybrids were assessed. Emulsions were prepared with different pectin concentrations (1, 2 and 3% w/w) and wax proportions (0.1, 0.2 and 0.3 g/g pectin). The rheological behavior was best described by the power law model. The values of the behavior index (n) were close to 1, exhibiting a behavior close to Newtonian fluids. The addition of waxes caused an increase in viscosity and shear stress. The particle size of the emulsions made with waxes from high-oleic sunflower was smaller than those from the normal hybrid. In most cases, size distributions with greater height and less amplitude were obtained, mainly when the pectin content was higher. Confocal images allowed to observe the presence of waxes and their dispersion in the pectin matrix. Destabilization phenomena such as sedimentation, coalescence and creaming were observed at long test times independent of the wax origin. These results evidence the potential use of these emulsions for the manufacture of edible films. [Display omitted] •Low-methoxyl pectin and sunflower wax aqueous emulsions were prepared.•The physical properties, particle size and stability were studied.•Destabilization phenomena were observed at long test times.•The production of edible films with pectin and sunflower wax emulsions is promising.