Effects of acetylated cassava starch on the physical and rheological properties of multicomponent protein emulsions

The present study investigates the effect of different acetylated cassava starch (ACS) concentrations on the physical and rheological properties of multicomponent emulsion-based products at specific pH values. The emulsion-based products were made by mixing 2% (w/v) prepared lipid droplets that were stabilized by either native or heated whey proteins, 0.01% (w/v) flaxseed gum and 0-6.0% (w/v) ACS. The results indicated that particle size, apparent viscosity and rheological moduli of multicomponent emulsion-based products were significantly enhanced with increasing addition amounts of ACS (P < 0.05). Moreover, the microscopic morphology showed that the addition of ACS contributed to the formation of a more compact, uniform, and continuous comb-like network. However, higher ACS concentration was prone to induce visibly larger aggregations and coarser textures, lending to some negative impact on visual appearance and overall acceptability. Moreover, acidic conditions could obviously promote droplet aggregation via electrostatic interactions, whereas neutral conditions had no effect on droplet aggregation. Additionally, when compared with native whey proteins, lipid droplets stabilized by their heated protein forms induced significantly higher apparent viscosities and rheological moduli of multicomponent emulsion-based products (P < 0.05). Our results potentially provide some information for the creation of multicomponent emulsion-based products with various desirable quality attributes.