Large amplitude oscillatory shear (LAOS) rheology of nixtamalized corn masa

Abstract

Masa was prepared by mixing 63.0 g of commercial nixtamalized corn flour and 37.0 g of water, and subjected to large amplitude oscillatory shear (LAOS) for assessing nonlinear viscoelasticity. Fourier decomposition of the stress time response was conducted to extract information on nonlinearities. The results showed that nonlinearities were expressed for large deformations higher than 1%. In contrast, the mechanical response was essentially harmonic for small amplitude values, indicating the absence of nonlinearities and hence the dominance of linear viscoelastic response. In particular, nonlinearities quantified in terms of the harmonic contributions were stronger for the elastic response (about 75–100%) than for the viscous response (less than 70%). The results illustrated the viability of LAOS method for characterizing the nonlinear mechanical response of masa made with nixtamalized corn flour.