Evaluating high pressure-treated corn and waxy corn starches as novel fat replacers in model low-fat O/W emulsions: A physical and rheological study.

High hydrostatic pressure-treated corn starch (HPCS) and waxy corn starch (HPWCS) at three concentrations (10%, 15%, and 20%) were applied as novel fat replacers in a model low O/W emulsion at three fat reduction levels (FR, 25%, 50%, and 75%) and some physical, textural and rheological characteristics and stability of the samples were examined and compared with the control. Applying higher concentrations of HPCS and HPWCS increased the zeta potential, hardness and consistency (mainly for HPWCS samples), reversely decreased the Z-average particle size and polydispersity index of the reduced-fat emulsions, but augmenting FR levels caused a reverse inclination. The rheological assay cleared that the emulsions prepared with HPWCS had greater elastic modulus (G') and more gap between G' and viscous modulus (G″) at all concentrations than the HPCS-contained samples. The critical stress (τ) of 25FR samples were significantly higher than the control, showing the well stability of reduced-fat samples. Also, the τ of the HPCS-contained emulsions reduced meaningfully when the FR level increased from 25% to 75%, but for the HPWCS samples, fat reduction didn't change the τ value significantly up to 50% fat reduction. Based on Tangδ, HPWCS contained samples showed more spreadability than the HPCS-contained emulsions.