- Glutenin: this is a type of protein that forms the interconnected gluten network and makes the dough elastic.
- Gliadin: this is another kind of protein component of the flour that bonds weakly to the glutenin network to make the dough plastic.
- Starch: It is a form of complex carbohydrate that will fill the gaps in the gluten network and absorb water during cooking. This will have for effect to tenderize the dough and set its structure during cooking.
- It will allow the the gluten network to form and dilute it. Depending on its quantity the final product will be more or less tender.
Yeast and Leavening Agents
- Composed of live cells in the case of the yeasts or purified chemicals in the case of the baking powder, these ingredients have the role of producing carbon dioxide gas (CO2) in the dough or batter. This has for effect to lighten and tenderize the final products.
- It is a purified mineral that has for effect to tighten the gluten network, thus bringing stability to the dough or batter. It make the dough more elastic.
Fats, Oils, Shortenings
- These ingredients are mainly made of lipids. They weaken the gluten network, tenderizing the final products.
- Sugar is purely made of carbohydrates. They will have for effect to weaken the gluten network and absorb moisture, making the final products tender and moist.
- The egg is essentially made of proteins, fats, natural emulsifiers (like the lecithin) and water. These various components of the egg will have very different, but complementary effects on the dough or batter. The first one, comes from the proteins. As the dough or batter cooks they coagulate and supplement the gluten structure with tender protein coagulum. The fats and emulsifiers weaken the gluten network, tenderizing the final products and slowing down the staling process. The other role taken by the natural emulsifier agents that are contained by the egg yolk, is to stabilize the bubbles of CO2 and the starch during the cooking process.
Milk and Buttermilk
- Essentially made of proteins, fats, natural emulsifiers and hydrogen based molecules (acids) milk or buttermilk weakens the gluten network and stabilizes the Co2 bubbles. The final products will, in effect, be tenderized and stale at slower rate.
To finish this little explanation, I would like to precise what I meant when I used the words plastic and elastic in relation to a dough.
Elastic, or elasticity and plastic, or plasticity are two qualities that are brought to a dough through the presence of gluten in the flour. It is characterized by the capacity of a dough to change shape under pressure, but still resist it and move back towards its original shape when the pressure is removed. This is why kneading bread by hand is not an easy job. I think everybody will agree with me on this! Thanks to this combination of properties, wheat dough can expand to incorporate the carbon dioxide gas produced by yeast or leavening agent, and yet resists enough that its bubble wall will not thin to the breaking point.
If you are interested in the elastic and plastic properties of wheat dough, I recommend you this study made by Dr Salme Taagepera, Lecturer and Academic Coordinator at the
Department of Developmental and Cell Biology at the University of California, Irvine, US. (Copy and paste this link in your browser) http://www.google.com/search?q=cache:DW4Ft0VszEMJ:https://eee.uci.edu/clients/staagepe/bio%25209b/powerpoints/lec15_16%2520dough%2520batter%2520c.ppt+gluten+plasticity+and+elasticity&hl=en&ct=clnk&cd=4&gl=ie