Viscoelastic Properties of Biscuit Doughs with Different Lipidic Profiles Fortified with a Casein Hydrolysate

Abstract

The effects of using a hard (artisanal) margarine (which has a higher lipidic and lower aqueous contents) and using a soft (commercial) margarine (which has a lower lipidic and higher aqueous contents), along with a casein hydrolysate, on the rheological properties of different biscuit short doughs were examined. The characteristic parameters in the linear viscoelastic range (LVER) were analysed by stress sweep at 6.3 rad/s and 25 °C. The two margarines showed similar values of strain amplitude (γmax), but the hard margarine exhibited a significantly higher firmness in the LVER, as expected. An analogous result was found for the biscuit doughs made with hard margarine and soft margarine. The addition of a casein hydrolysate (CH) to both biscuit doughs produced an increase in the loss factor, indicating a loss of the solid-like character in the dough networks. Nevertheless, a different trend in the consistency of the dough, which depended on the type of margarine, was found. While, after adding CH, the dough made with soft margarine showed a significant reduction in rigidity, the dough with hard margarine exhibited an increased firmness upon CH addition. Yield stress tests showed that CH facilitates the transition from elastic to plastic deformation at the yield point more intensely in the dough with soft margarine.