Wheat flour contains gliadin and glutenin, which in the presence of water and additional kneading and mixing bind together into a flexible network which is called gluten. This network of proteins is responsible for our pastry to hold its shape and contributes to is textural and physical characteristics. Therefore it is essential to control the development of this Gluten network. Too few gluten would make the cake structurally instable and too much would make it too rigid, hard or too elastic.
Gluten and its origin
Proteins make up about 10 – 15% of the dry weight in a wheat grain. Out of those around 80 % account for the proteins gliadin (monomers) and glutenin (complex aggregates) (Bonomi et al., 2014, p.56). When the seed is in it’s germination process, those proteins provide additional reserve of amino acids (Wrigley et al., 2006, p.2).
Flour is just pulverized wheat grains with gliadin and glutenin distributed all over the place but not yet attached to each other. Adding water to the wheat flour leads to structural changes even in the absence of mechanical treatments and further mixing and kneading increases those structural modifications (Bonomi et al., 2014, p.66).
Through those actions, gliadin and glutenin are rearranged into a three-dimensional webwork of complex protein composition – gluten (see Fig. 1). Gluten exhibits plastic and elastic properties and is therefore able to envelop gas bubbles in it. Above 85 °C that complex protein webwork coagulates irreversibly, losing the aforementioned properties without losing its newfound shape, thus providing structural integrity to the baked good (Kalin, 1979, p.477).
Consequences for baking – controlling gluten development
Gluten development describes the process of creating this essential gluten webwork while mixing the dough. Creating too few gluten by mixing too less, will create a batter with weak structural integrity. It would rise through leavening agents but also fall due to the non existence of structure. Mixing too much will create an overelastic network with too strong and sturdy texture. A cake batter would rise but also due to the heavy elastic structure contract back again. Overkneading occurs, when the proteins fall into a „random coil“ structure, which do not contribute to the gluten network anymore (Bonomi et al., 2014, p.68).
Therefore, it is essential to find the sweet spot of mixing and kneading. You will sometimes find specific instructions for cake recipes, which tell you to blend in the dry ingredients (including flour) as part of the last step, as to not accidentally develop too much gluten.
Furthermore, other components might interact with the development of the gluten network as well. For example, some oils, which are commonly known as shortening agents, have a coating effect and help to create smaller networks and thus crumblier dough (Bonomi et al., 2014, p.69) (also see bobsredmill.com).
Further Implications:
- As soon as water is added gluten is developed, so sometimes it might not be a good idea to prepare a dough one day beforehand
- Different types of cereals do contain different amount of gluten, which affect the resulting dough differently
Experiment
1 leave dough in kitchen
mix dough differently
References
Bonomi, F., Ferranti, P., & Mamone, G. (2014). Wheat Flour: Chemistry and Biochemistry. In W. Zhou, Y. H. Hui, I. De Leyn, M. A. Pagani, C. M. Rosell, J. D. Selman, & N. Therdthai (Hrsg.), Bakery Products Science and Technology (S. 55–74). John Wiley & Sons, Ltd. https://doi.org/10.1002/9781118792001.ch3
Kalin, F. (1979). Wheat gluten applications in food products. Journal of the American Oil Chemists’ Society, 56(3Part3), 477–479. https://doi.org/10.1007/BF02671549
Wrigley, C., Békés, F., & Bushuk, W. (Hrsg.). (2006). Gliadin and Glutenin: The Unique Balance of Wheat Quality. AACC International, Inc. https://doi.org/10.1094/9781891127519
Further Readings
Hamer, R.J. „Chapter IV Gluten“. In Progress in Biotechnology, 23:87–131. Elsevier, 2003. https://doi.org/10.1016/S0921-0423(03)80004-7.
Preichardt, Leidi Daiana, und Márcia Arocha Gularte. „Gluten formation: its sources, composition and health effects“. Walter, DB, 2013, 55–70.
