Exploration of bread making
What I will cover in this post?
In this post, I will talk briefly about the science of bread, go through the optimisation of a bread recipe, testing several parameters including yeast content, hydration and the impact of freezing the dough before cooking. I will end this post by investigating wheat-based composites (basically mixtures of various wheat and non-wheat based flours).
A bit of science behind bread
9.5.2024
Flour contains proteins glutenin and gliadin, which are hydrophobic (water-hating) peptides. In the presence of water, they will self-assemble to form gluten (Fig 1), which is a result of the molecule preventing the hydrophobic regions from interacting with water. Prior to the addition of water, glutenin exists as a colloid. Upon addition of water to the flour, the chains are allowed to stretch, seperate, and form new disulfide linkages. These disulfide linkages create a network of glutenin polymer that produces the strength and elasticity of bread dough. At the same time, the smaller gliadin proteins will disperse through the glutenin polymer network, which allows the bread to "rise". It is the constituent that facilitates formation of the gluten network. Due to it's self-assembling properties (as it is highly hydrophobic), it will associate into spherical particles and absorb other nutrients such as vitamin E. Thus, the quality of the gluten network that forms is dependent on the type of flour that is used.
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| Fig 1. Schematic of gluten formation |
Mixing and kneading of the flour/water mixture encourages the gluten network to further develop. During this process, carbon dioxide is incorporated, producing a more porous dough once it is baked. Yet, we dont want the gluten networks to be so strong that they become chewy and tough. This is the reason that people turn to a "no-knead" method. Sometimes, a high water content is enough to facilitate formation of strong gluten networks.
Yet, there is one more ingredient that is required to create the gluten network... and that is salt. As mentioned in the "salting-out" post, salt helps to decrease the water content. In this instance, salt will remove water from the protein/polymer network to increase the strength and elasicity.
References
- Cho, I.H. and D.G. Peterson, Chemistry of bread aroma: A review. Food Science and Biotechnology, 2010. 19(3): p. 575-582.
- Sha, X., et al., The prolamins, fro structure, property, to the function in encapsulation and delivery of bioactive compounds. Food Hydrocolloids, 2024. 149: p. 109508.
- Taghdir M, Mazloomi SM, Honar N, Sepandi M, Ashourpour M, Salehi M. Effect of soy flour on nutritional, physicochemical, and sensory characteristics of gluten-free bread. Food Sci Nutr. 2017; 5: 439–445. https://doi.org/10.1002/fsn3.411