The effect of laccase enzyme addition to soft Syrian wheat flour or blending with durum flour on the rheological properties of dough

Abstract

Wheat is one of the most important crops in the world, its products, especially fermented baked goods, take a major role in the diet. These products require strong flour. In Syria, about 20 – 25% of improved durum wheat is blended with soft wheat to increase the strength of the flour. Laccase enzyme, is one of the important oxidative enzymes, which is added to increase the strength of the dough. Several devices have been used to evaluate flour and measure the properties of dough, but none of them is able to predict all the properties in a single test one. A new instrument Mixolab dough characterizer has been developed to measure the dough properties and the pasting behavior of flour at the same time. Hence, in the present research Mixolab dough characterizer was used to assess the effect of the addition of laccase enzyme and blending of durum and soft Syrian wheat on the rheological properties of wheat flour (80% extraction). The results showed that the values of C 2 (decrease in dough consistency due to excessive mixing), water absorption, and dough development time increase after the addition of laccase enzyme and blending durum and soft wheat, as well as the dough stability increases too, therefore, it can be concluded that, both the addition of laccase and blending durum and soft wheat increase dough strength, but the addition of laccase treatment has higher values of dough stability and gluten index compared to blend flour. The effect of the two treatments on the properties of the starch differed; the values of C 3 (starch gelatinisation), C 4 (gel stability), and C 5 (starch retrogradation) are increasing with laccase addition, while these values are reducing with the blending of durum and soft wheat.