Challenges in determination of rheological properties of wheat dough supplemented with industrial by-products: carob pod flour and sugar beet fibers

Abstract

The rheological behavior of dough supplemented with sugar beet fibers (SBF) and carob (pod) flour (CF), as fiber-rich by-products of the agricultural industry, was investigated using the standard Brabender extensograph and the Kieffer micro method. The addition of CF (0–20%) and SBF (0–6%) to the wheat dough formulation increased resistance to extension to about 75% and 55% respectively, while the combined effect of CF and SBF addition increased the dough resistance by up to 100%. The extensibility of the dough decreased in almost identical ranges (up to 40%), while the combined effect of CF and SBF addition had a stronger influence on the decrease in dough extensibility (75%). The evaluation of the correlation between the extensographic and the Kieffer micro method showed a high compatibility with regard to the results of the dough extensibility (r = 0.89, p < 0.05), but did not confirm the agreement of the results obtained in the resistance measurements (r = 0.13, p < 0.05). Considering that the absolute correlation between the two rheological methods used was not confirmed in this study, it is clear that the precise and complete definition of rheological properties requires the use of other methods, not only empirical but also fundamental.