Rheological properties of gluten free dough systems
Abstract
Bread is the one of the oldest processed foods and a major wheat based product. The basic process involves mixing of ingredients until the flour is converted into dough, followed by baking the dough into a loaf. A very important step in breadmaking is to know how to make good quality dough. However, the increasing knowledge of people being diagnosed with celiac disease (gluten intolerance) has encouraged scientists to develop healthier and better quality gluten-free products that would greatly improve the quality of life of celiac patients. The main objective of this study was to create a dough system composed of mainly maize proteins that would be able to reproduce same rheological properties as wheat gluten in breadmaking. The dough composites were made of Zein + co-protein + starch and were mixed at 25°C and 35°C. Three types of starches (corn, wheat, and rice) were used to better understand the interaction between starch and the proteins. Also, four different co-proteins (casein, sodium caseinate, gliadin and glutenin) were added to the system to determine the effect in zein functionality and its contribution to the viscoelastic dough system. Each sample was subjected to frequency test in a DHR-3 Rheometer and to lubricated squeezing flow test in order to determine the rheological properties of each dough sample such as phase angle (delta), complex modulus (G*), and extensional viscosity (μ b). Moreover the glass transition temperatures of the different protein + starch samples were analyzed using the oscillatory squeezing flow technique. In small and large deformation tests, rice starch doughs showed similar or slightly improved rheological properties when compared to gluten. Rice starch doughs also showed a lower glass transition temperature than gluten doughs when mixed at both temperatures when tested under OSF method. Overall, not only protein plays an important role when making bread dough. Similar wheat flour dough properties can be obtained with corn and rice starch when mixed with zein and other co-proteins at 35°C. The glass transition temperature plays an important role in determining zein's behavior in a dough system. Addition of co-protein showed to have an effect in dough formation when zein becomes more mobile at 35°C.
Degree
M.S.A.B.E.
Advisors
Campanella, Purdue University.
Subject Area
Food Science|Agricultural engineering
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