Characterization of sodium caseinate/Hydroxypropyl methylcellulose concentrated emulsions: Effect of mixing ratio, concentration and wax addition.

The effects of mixing ratio (1:1, 2:1 and 4:1 sodium caseinate: Hydroxypropyl methylcellulose, CN:HPMC), HPMC concentration (0, 0.6 and 1.2 wt%), CN concentration (0, 1.25 and 2.5) and beeswax addition (3%) on the physical stability of concentrated O/W emulsions (φoil = 0.6) were investigated. The emulsion stability, particle size distribution, microstructure and rheological properties were measured. The results showed that emulsion stability was significantly improved with increasing HPMC concentration (p < 0.05). The samples with the highest and the lowest biopolymers concentration at mixing ratio of 2:1 had the highest and the lowest ESI (98% and 48%), respectively. In addition, the most stable sample had the smallest volume mean diameter and approximately desirable rheological properties. The beeswax addition considerably improved rheological properties whereas increased droplets diameter and emulsion instability. In summary, concentrated emulsions stabilized by caseinate/Hydroxypropyl methylcellulose complex may be useful for application in particular food such as heavy cream, mayonnaise, oleogels and pharmaceutical products.