Emulsifieres: effecto of texture properties of wheat dough

GÓMEZ, A.; AÑÓN, M. C.; PUPPO, M.C.

Madrid, España

Congreso; 13the ICC Cereal and Bread Congress. “Cereals worldwide in the 21th century: present and future”; 2008

ICC International

Wheat flour dough is a viscoelastic material with rheological properties between a viscous liquid and an elastic solid (Weipert, 1990). Elasticity and tenacity affect dough machinability and textural characteristics of the final product. Emulsifiers like sodium stearoyl lactylate (SSL) and diacetyl tartaric acid esters of mono and diglycerides (DATEM) are anionic compounds widely used to improve breadmaking. These additives bound to the hydrophobic regions of gluten proteins promoting aggregation due to neutralization of positive charges. During dough mixing and breadmaking, the major functions of these compounds are reinforcement of the gluten network, increase of dough strength and extensibility, and improvement of the loaf volume (Stauffer, 1990). The objective of this work was to study the influence of SSL, DATEM and a blend of both emulsifiers on the rheological properties of dough made with commercial Argentinean wheat flour. Formula included wheat flour (100 g), NaCl (2 g), SSL, DATEM or a 1:1 blend of SSL:DATEM (1% and 5% flour basis). Dough deformation resistance was determined by alveographic parameters (P, L, W). Dough texture (hardness, consistency, adhesiveness and cohesiveness) and relaxation (elasticity, relaxation time) were studied by a modified TPA method, at a low deformation level (20%) with a TA-XT2i Texture Analyzer. Whatever their concentration, emulsifiers did not modify tenacity (P) of the control dough. Extensibility (L) of dough prepared with DATEM (1 and 5%) was lower than that observed for dough without additives. At both levels, dough prepared with the blend of emulsifiers had L values similar to those obtained with SSL only. These results suggest that in a 1:1 mix, the SSL governs the extensibility of dough. On the other hand, work (W) performed to dough during the alveographic extension was not significantly modified with the incorporation of pure or blended emulsifiers at both levels. The incorporation of 1% of DATEM or blend caused a significantly decreased in dough consistency and hardness. At 5%, only SSL significantly increased these parameters. Between emulsifiers, no significant differences in adhesiveness and cohesiveness were observed. Results suggest that dough texture was mainly influenced by DATEM. At the 5% level, relaxation tests showed that dough elasticity was higher, especially with DATEM. Incorporation of emulsifiers, especially DATEM, increased dough relaxation time. High hydrophobic components such as DATEM gave dough which was more elastic although less extensible and more resistant relaxation. Different effects of each emulsifier on dough extensibility, relaxation and texture might be attributed to their distinct chemical formula, acting on specific gluten network chains. Distinct interaction between gluten proteins, mediated by the emulsifiers, would lead to dough with specific breadmaking properties.