Influence of pH value and locust bean gum concentration on the stability of sodium caseinate-stabilized emulsions

Abstract

Sodium caseinate emulsions of 20% sunflower oil in water were prepared at various pH and Locust Bean Gum concentrations (LBG). The presence of LBG was examined to assess the stabilizing properties in relation to flocculation, creaming and coalescence, in the initial emulsions as well freezethawed and freeze-dried/reconstituted samples. We found the initial emulsions to be stable at pH 6 and 6.5, both in absence or presence of LBG, against creaming. However we found evidence for the presence of emulsion droplet aggregates in the presence of LBG. Strong shear thinning behavior, even at low shear rates, and micrographs indicated that the presence of LBG may promote flocculation by mediating depletion forces between the oil droplets. However, the absence or low concentrations of LBG resulted in creaming followed by the emulsion break-up for the freezedried/reconstituted emulsions, particularly at lower pH. We have also detected a proliferation in the number of very small sub-micron particles in the particle size distribution, for samples containing higher concentrations of LBG, following the freeze-thaw cycle. We believe these to be LBG aggregates nucleating during the freezing phase of the process as the polysaccharide solubility declines with temperature.

Stabilization of soybean oil by flaxseed gum and NMR characterization of its oil–water interface

“…However, the D4,3 values were only 21.08 μm for emulsions with 0.5% FG, which decreased nearly 66%. These findings indicate that a high FG concentration could contribute to the formation of smaller particle sizes and enhance the stability of emulsions, and these findings are consistent with the results of previous studies (Bai, Huan, Li, & Mcclements, 2017;Farshchi, Ettelaie, & Holmes, 2013;Wang et al, 2017).…”

Structure and texture development of food-emulsion products

“…l Electrostatic repulsion can be decreased by altering the pH to reduce the surface charge or by increasing the ionic strength to screen the surface charges (Farshchi et al, 2013;McClements, 2012a). l Hydrophobic attraction can be promoted by increasing the surface hydrophobicity of droplets, for example, by heating globular protein-stabilized fat droplets above their thermal denaturation temperature (Dickinson, 2010a;Lam and Nickerson, 2014).…”

“…l Hydrophobic attraction can be promoted by increasing the surface hydrophobicity of droplets, for example, by heating globular protein-stabilized fat droplets above their thermal denaturation temperature (Dickinson, 2010a;Lam and Nickerson, 2014). l Depletion attraction can be increased by adding nonadsorbing biopolymers or other nonadsorbing colloidal particles to the aqueous phase to increase the osmotic pressure acting between droplets (Dickinson, 2010a;Farshchi et al, 2013). l Bridging flocculation can be induced by adding oppositely charged polymers or mineral ions to form ionic bridges between different droplets (Dickinson, 2010a;Guzey and McClements, 2007).…”

Functional Chia Oil‐in‐Water Emulsions Stabilized with Chia Mucilage and Sodium Caseinate

“…In addition, with respect to the color of chia oil, the following ranges were obtained for the parameters L, a, and b: 43.18 to 67.48, −4.55 to −6.56, and 28.27 to 28.38, respectively (Ixtaina et al, 2011;Julio et al, 2015;Timilsena, Vongsvivut, Adhikari, & Adhikari, 2017). There are studies that indicate that the simultaneous incorporation of different polysaccharides and NaCas into O/W emulsions favors emulsion stability, due to an increase of viscosity for the continuous phase of the emulsion and promotion of the electrostatic repulsions between the droplets (Farshchi, Ettelaie, & Holmes, 2013;Hemar, Tamehana, Munro, & Singh, 2001;Perrechil & Cunha, 2010). It has also been demonstrated that chia mucilage dispersions of different concentrations have a stabilizing effect in O/W emulsions stored at 4 C Guiotto, Capitani, Nolasco, & Tomás, 2016).…”

“…It consists of four different proteins: α s1 , α s2 -, β-, and κ-casein in a weight proportion of approximately 3:0.8:3:1, respectively (Jahaniaval, Kakuda, Abraham, & Marcone, 2000). There are studies that indicate that the simultaneous incorporation of different polysaccharides and NaCas into O/W emulsions favors emulsion stability, due to an increase of viscosity for the continuous phase of the emulsion and promotion of the electrostatic repulsions between the droplets (Farshchi, Ettelaie, & Holmes, 2013;Hemar, Tamehana, Munro, & Singh, 2001;Perrechil & Cunha, 2010). On the other hand, oil-in-water emulsions have been developed with chia oil as potential delivery systems of ω-3 fatty acids, stabilized with NaCas and lactose, indicating that their behavior is mainly influenced by the NaCas content and lactose addition (Julio et al, 2015).…”