SURFACE RHEOLOGICAL PROPERTIES OF SODIUM STEAROYL-2-LACTYLATE (SSL) AND DIACETYL TARTARIC ESTERS OF MONO (AND DI) GLYCERIDE (DATEM) SURFACTANTS AFTER A MECHANICAL SURFACE-TREATMENT IN RELATION TO THEIR BREAD IMPROVING ABILITIES

The surface dilational moduli of suspensions of the surfactants sodium stearoyl-2-lactylate (SSL) and diacetyl tartaric esters of mono (and di) glycerides (DATEM) were determined by means of the so-called ring trough technique. It was investigated whether these surfactants could provide the surface with a high surface stiffness by giving the surface a mechanical treatment at room temperature. It appeared that both SSL and DATEM suspensions have high surface dilational moduli (500-1000 mN m(-1)) after having undergone such a mechanical treatment. These values are of importance in retarding disproportionation in bread dough. The tested surfactants also lower the surface tension of dough leading to the subdivision of the entrapped air bubbles into more and smaller bubbles during mixing.