Viscoelastic behavior of nixtamalized maize starch gels

The influence of lime and amylose–lipid complexes on the viscoelastic behavior of nixtamalized maize starch gels was studied using small amplitude oscillatory rheometry. The storage modulus (G′) and the loss modulus (G″) behavior showed to be lime dependent. At 0.2% w/v lime, both moduli had the highest values, and decreased with increasing lime concentration. This dependent lime behavior pattern was attributed to changes in the Ca–starch interactions, affecting swelling and solubility. Fourier transform infrared (FTIR) spectra indicated that amylose–lipid complexes are present in starch gels of maize nixtamalized with or without lime. The effect of these complexes on preventing amylose solubilization was surpassed by the stabilizing effect of the Ca–starch interactions on starch granule structure, as evidenced by scanning electron microscopy (SEM). Thus, it is suggested that the rheological properties of nixtamalized maize starch gels are influenced mostly by the effect of Ca–starch interactions.