Water and temperature contribution to the structuration of starch matrices in the presence of flavour

Abstract : The effect of modulating the gelatinisation extent by hydration (50/50 and 80/20 water to starch ratio) and temperature (65 or 85 degrees C) on various properties of wheat starch in presence of flavours has been studied. The hydrothermal treatments resulted in samples with different properties. The lowest residual flavour content was found in samples treated at the highest hydration and temperature (85 degrees C) while the other treatment conditions led to samples with similar residual flavour content. Ethyl hexanoate significantly increased the characteristic pasting viscosities compared to starch +/- 2-hexanone; suggesting a greater structuration with ethyl hexanoate. Heating starch in excess water caused amylopectin melting, but promoted an incomplete granular swelling as revealed by RVA. This study suggested that lowering the hydration upon treatment could limit both crystal melting (with a residual crystalline content up to 38% in the most extreme conditions) and granular swelling but increased granule organisation like following annealing.