Interest in the grain amaranth has increased in recent years due to its great potential as a functional food. The investigation showed the effect of soaking conditions in an acid atmosphere (temperature and concentration of SO2 ) on thermo-viscoelastic behavior of the protean fraction (FP) of the amaranth grain. It used a 32 factorial design, involving two factors: temperature (40-60°C) and concentration of SO2 (0,01-0,1% w/v). By the same way, it used a dynamic oscillatory rheometry, with heating and cooling cycles (25-90°C), tempered at 90°C, and followed by a frequency sweep (0,1 to 10 Hz) at a constant temperature. The viscoelastic module (MV) and the thermal properties were affected by both factors, with significant interaction effects. Mechanical FP spectra were previously denatured by sweeping from 0,1 to 10 Hz at 25°C, and constant (0,5%) deformation. The results revealed the formation of gels whose character depends on the soaking conditions. The different conditions of maceration caused different degrees of denaturation of the protein components, which influenced the rheological behavior