Rheological properties of wheat flour dough : a dissertation presented in partial fulfilment of the requirements for the Master in Food Technology of Massey University

Abstract

Among all cereals, wheat is the most abundant food crop worldwide. Wheat is commonly milled to wheat flour which could be further treated by other chemical methods depending on its utilisation. There are more than thousands bakery products using wheat flour as the main ingredient around the world. However, the most important use of wheat flour is for bread (Kokelaar, 1994). Due to its viscoelastic behaviour, which is not yet fully understood wheat flour doughs are complex systems that create great challenges in process engineering and product development research. Szczesniak (1988) gives the most striking definition of dough--'it is alive'--referring to its condition of a dynamic system continually changing due to physical and chemical factors. Many scientists are interested in wheat flour dough rheology because wheat flour dough is unique and different from other flour doughs. Also, during breadmaking, dough undergoes different type of deformation in every phase of the conversion of wheat flour into baked products. During mixing, dough is subjected to extreme deformations that may exceed its rupture limit. During sheeting, fermentation, proofing, shaping and baking, the properties of wheat dough vary largely (Hoseney, 1986). All of these changes affect the final quality of baking products. If the rheological properties of wheat flour dough were fully understood it would facilitate quality control of baking products and improvement of the bread making process.