Impact of HHP-treated starches on LAOS, tribology, and steady shear behavior of reduced-fat O/W emulsions

The present study aimed to scrutinize the influence of high hydrostatic pressure (HHP)-treated starches, including wheat starch (HPWS), corn starch (HPCS), and waxy corn starch (HPWCS) at different concentrations (10%, 15%, and 20%) as fat replacers on the large amplitude oscillatory shear (LAOS), tribological, and steady shear rheological characteristics of model O/W emulsions at three fat reduction (FR) levels (25%, 50%, and 75%). By increasing the FR level, greater nonlinearity, higher friction factor, and lower recovery percentage were observed for HPWS- and HPCS-contained samples, though HPWCS-contained samples showed lower nonlinearity. Using HHP-treated starches with higher concentration at each FR level, the extent of nonlinearity (regardless of elastic or viscous) and the quantities of friction factor decreased meaningfully and the values of strain stiffening and shear thickening factors increased. The values of G3 '/G1 ' of reduced-fat emulsions were significantly higher (24%-72%) than the magnitudes of G3 /G1 (except for the 75% reduced-fat samples).

Automated summary

This study examined the effects of high hydrostatic pressure-treated starches on the rheological properties of model O/W emulsions at different fat reduction levels. It was found that as the fat reduction level increased, the samples containing HPWS and HPCS showed higher nonlinearity, friction factor, and lower recovery percentage. However, samples containing HPWCS exhibited lower nonlinearity. When using high concentration of HHP-treated starches, the nonlinearity decreased, while the strain stiffening and shear thickening factors increased. The G3'/G1' values of reduced-fat emulsions were significantly higher compared to the G3/G1 values.