Effect of sucrose fatty acid esters on pasting, rheological properties and freeze–thaw stability of rice flour

The present research is aimed to evaluate the effects of sucrose fatty acid esters (SEs) on the pasting, rheological properties and the freeze–thaw stability of rice flour. Four types of SEs including S-570, S-970, S-1170 and S-1570 with hydrophilic–lipophilic balance (HLB) values varying from 5 to 15 have been compared. Viscosity behavior of rice flour with different SEs was first measured with the Rapid Visco Analyzer (RVA). The RVA profile showed that pasting temperature, peak and final viscosities of rice flour gels increased with SEs addition except for S-570. Rheological properties including the steady shear characteristics, the viscoelastic parameters (storage and loss moduli) and the creep-recovery response were determined. The obtained steady shear and creep data were fitted by power law (R2 > 0.983) and Burgerʹs models (R2 > 0.993) respectively. The results revealed that the addition of SEs except for S-570 increased the storage and loss moduli, apparent viscosity, flow behavior index and the retardation time, and decreased loss tangent. Finally, the freeze–thaw measurement demonstrated that all types of SEs enhanced the freeze–thaw stability of rice flour with the order of S-1570 > S-1170 > S-970 > S-570. These results could have important theoretical and practical implications in choosing suitable SEs for the particular requirements of final food products based on rice flour.