Understanding of the key factors influencing the properties of emulsions stabilized by sodium caseinate

Abstract

Emulsions can be easily destabilized under various conditions during preparation and storage. Therefore, it is necessary to understand the factors that influence the stability of emulsions, which is essential for their subsequent studies. Sodium caseinate (CAS) is a well-used nutritional and functional ingredient in emulsion preparation due to its good solubility and emulsifying properties. CAS-stabilized emulsions can be considered good food emulsion delivery systems, but their applications are still limited under certain conditions due to their instability to creaming and aggregation. Therefore, the purpose of this review is to provide a complete overview of how different environmental stresses and processing conditions affect the stability of CASstabilized emulsions and how to improve their stability. Initially, the general properties of CAS as emulsifiers and the characterization of CAS-stabilized oil-in-water (O/W) emulsions were summarized. Second, the major instability mechanisms that operate in CAS-stabilized emulsions were presented. Furthermore, the general factors such as pH, emulsifier concentration, ionic strength, oxidation, and processing conditions, affecting the stability of CAS-stabilized O/W emulsion, were discussed. On this basis, the commonly used methods for evaluating emulsion stability are introduced. Finally, state-of-the-art strategies to improve CAS-based emulsion stability are also described and summarized. This review is expected to provide a theoretical basis for the future applications of CAS in food emulsions.

Critical Review of Techniques for Food Emulsion Characterization

“…A more elastic adsorption layer can give the emulsion viscoelastic properties, such as shear-thinning. Conversely, if the relative rigidity of the interface is high, the rheological behavior of the emulsion may mimic a dispersion of solid particles [129].…”

Research advances in Zein-based nano-delivery systems

“…Casein is the main protein of milk in the form of macromolecular aggregates (105,106). Sodium tyrosine is a commonly used nutrient and functional component in emulsion preparation due to its good solubility and emulsification properties (107). Caseinate moves the isoelectric point of the colloidal particles from 6.0 to around pH 5.0, thus preventing Zein from accumulating near its native IEP (pH 6.2) and is the most commonly used stabilizer for Zein nanoparticles (108,109).…”

Casein‐based conjugates and graft copolymers. Synthesis, properties, and applications

“…The main functional properties of casein are water solubility, viscosity, gelation, emulsifying, and foaming properties. Casein has a major application as an additive in food industry (Wusigale et al., 2020), but increasingly in other areas, such as emulsifiers (Liao et al., 2022; Ma & Chatterton, 2021), paint (Nevin et al., 2008), adhesive (Tundisi et al., 2021), packaging (Khan et al., 2021), incorporation and delivery of active drugs (Głąb & Boratyński, 2017; Nascimento et al., 2020; Sadiq et al., 2021), and textile manufacturing (Belkhir et al., 2021). The industrial production, specifications, and regulatory aspects of casein are summarized in a previous review (O'Regan & Mulvihill, 2011).…”