Gluten proteins: Influence of baking emulsifiers in rheological properties of wheat dough

GÓMEZ, A.; AÑÓN, M. C.; PUPPO, M. C.

Rosario, Santa Fé, Argentina

Conferencia; 1 Conferencia Latinoamericana- ICC 2007 – ICC International Conference on Cereals and Cereal Products Quality and Safety; 2007

ICC International

The baking quality of wheat flour depends on the quantity and quality of the gluten proteins during mixing. These proteins, mainly gliadins and glutenins, form matrix dough with distinct rheological properties. Dough rheological characteristics such as tenacity, elasticity and viscoelasticity are determined by the nature of protein aggregates of different molecular mass that are stabilizing gluten structure. This dough, capable to retain carbon dioxide during fermentation, determine in bread making the final quality of crumb. Emulsifiers are substances able to interact with gluten proteins and starch during dough formation, reinforcing gluten structure and increasing bread volume. However, not enough information is available about the mechanisms of these additives in the improvement of gluten structure. Therefore, the objective of this work was to study the influence of emulsifiers of different chemical structure, in the nature of protein aggregates produced during dough formation. The relationship between these aggregates and rheological properties of dough was also analyzed. Dough was prepared with commercial wheat flour (000 argentinian type). Sodium stearoyl lactylate (SSL) and diacetyl tartaric acid esters of monoglycerides (DATEM) were used as emulsifiers. Emulsifiers were used in diferente mixes of SSL:DATEM: 100:0, 75:25, 50:50, 25:75, and 0:100, at concentrations of 1% and 5% of total additive content. Tenacity (P), extensibility (L) and dough strength (W) were characterized by alveographic assays. Analysis of total, gliadin and glutenin proteins was performed by SDS-PAGE. Emulsifiers did not modify, in any proportion, tenacity of control dough, while extensibility decreased and increased with 1% DATEM and 1% of SSL, respectively. Five percent of additive diminished L and W, mainly with DATEM. A synergic effect in L and W values was observed for the blend that contains 50% of each additive, at both levels (1% and 5%). These values were higher than those observed for the dough prepared without additives (control dough). This effect could be attributed to the action of each emulsifier at different regions of the gluten matrix, due to their distinct chemical formula. SDS-PAGE analysis showed an increase in the proportion of soluble aggregates extracted from dough prepared with SSL. These aggregates were mainly formed by high molecular mass glutenins. The type of emulsifier-protein interaction, electrostatic or hydrophobic, determines the nature of macropolymers that stabilize gluten network. Optimum dough rheological properties, determined by the structure of these macropolymers, are needed for obtaining good quality bread.