Abstract

Background: Wheat flour quality varies largely, affecting the quality of the final baked products. In order to fulfil the consumer’s demand for bakery products with high quality and extended shelf-life different types of improvers have been used in the bakery industry. This study aimed to investigate the effect of different bread improvers on rheological parameters of dough made from all-purpose wheat flour comparing that with strong, soft, extra-soft and pastry wheat flour.

Methods: One all-purpose wheat flour (control) was used in this study. As improvers of the control flour ascorbic acid (AA), citric acid (CA) and L-Cysteine (CYS) were used at levels of 30 and 60 ppm, 10 and 20 ppm, 20 and 40 ppm on flour base, respectively. These improvers are generally recognized as safe (GRAS) within the EU. The tested flours were analysed by determination of several dough rheological parameters on alveograph, farinograph and extensograph. One strong wheat flour, one soft wheat flour, one extra soft wheat flour and one pastry flour were used for comparative reasons in this study. All the flours were refined at 70% extraction.

Results: At the levels used, AA increased the dough tenacity (P) and decreased the dough biaxial extensibility (L) whereas the opposite was observed for CYS. On the other hand, CA addition did not significantly affect the dough tenacity but decreased biaxial extensibility. Extensograph measurements showed that the resistance to deformation was increased compared to control when AA and AC were added but decreased with the addition of CYS. Although the water absorption level was not affected by the addition of improvers the dough development time was decreased. AA increased the stability whereas CA and CYS decreased. Variations were observed due to the addition of improvers. They altered the rheology of the control dough but were not able to reassemble all the rheological characteristics of the commercial special flours used for comparative reasons in this study.

Conclusion: The addition of improvers significantly affected the rheology of the dough but the extent was dependent on the type of additive added as well as the level added. CYS was more effective in decreasing the energy required to expand the dough, decreasing the flour strength compared to AA and CA. Thus, depending on baker’s needs, the type and amount of additive added differed.