Emulsifiers increase the bread dough stability. This allows bakers to proof their dough for longer which results in a larger loaf volume. Adding to that, emulsifiers soften the bread crumb and delay hardening during storage. The most common emulsifiers used in bread making are diacetyl tartaric acid ester of monoglycerides (DATEM), sodium stearoyl lactylate (SSL), mono- and diglycerides, monoglyceride derivatives, lecithin, and polyglycerol esters of fatty acids (PGEF).
What do emulsifiers do in bread dough?
Emulsifiers have a polar hydrophilic (water-loving) and a non-polar hydrophobic (water-repellent) part. This enables them to bind to polar substances (eg. water) as well as to non-polar substances (eg. oil). If you have a mixture of water and oil, then the emulsifiers will accumulate at the oil-water interface and stabilize the emulsion by decreasing the interfacial tension.
In bread dough, we don’t need emulsifiers to prevent the dough from separating into an aqueous and an oil phase. The dough is viscous so that lipids cannot move around freely. Their mobility is limited by the dough consistency. Instead of the term emulsifier, it is better to use the word surfactant to describe the role of these molecules in bread dough.
The emulsifiers used in bread making interact with:
- the gluten proteins to strengthen the dough
- the gelatinized starch to delay bread staling
The binding of the emulsifiers to the lipophilic part of the gluten proteins happens during the mixing of the dough. This increases the gluten protein aggregation and subsequently the dough development time. It also stabilizes the dough so that it can withstand excessive kneading. One of the best emulsifiers, DATEM, is believed to form hydrogen bonds with gluten and starch which strengthens the bread dough structure.
Emulsifiers also increase the incorporation of tiny gas bubbles during dough mixing. This has a significant effect as all the air bubbles in the final dough are created during the mixing process. The fermentation of bread dough just serves to expand the pre-existing gas bubbles. The more tiny nucleation bubbles we have in our dough, the lighter and softer the crumb.
Emulsifiers allow the dough to incorporate more gas bubbles during mixing because they stabilize the protein-lipid interface around the gas bubbles in bread dough. If a gas bubble is unstable, it tends to merge together with surrounding gas bubbles to form one large gas bubble. However, we typically want to achieve a crumb with as many small to medium gas bubbles as possible instead of just a few extra-large ones surrounded by dense and gummy areas that are hard to chew.
Another function of emulsifiers is to suppress the binding of free lipids to other dough components like gluten. Adding to that, the best emulsifiers for bread making can stabilize expanding gas bubbles during fermentation as they form liquid crystals that stabilize the gas-aqueous dough interface.
As I have already discussed in my post about alpha-amylase, to delay bread staling we need to disrupt either one of the two starch networks that get formed once the bread is baked. The retrogradation (crystallization and network rearrangements) of the starch after baking is the main reason why bread hardens during storage.
While alpha-amylase helps to weaken the amylopectin network, many emulsifiers can form complexes with amylose and thereby inhibit the amylose gel network formation. While emulsifiers typically prefer to form complexes with amylose, to a much lower extent, they can also bind to amylopectin and decrease the amylopectin crystallization and network formation.
Which emulsifiers are used in bread making?
Emulsifiers are typically added to bread dough in concentrations of 0.2-1 % in relation to the flour weight. Below you can find a table of the most common emulsifiers used in bread making and their technological function.
|DATEM (diacetyl tartaric acid ester of monoglycerides)||Increases loaf volume, decreases crumb hardness, anti-staling agent|
|SSL (sodium stearoyl lactylate)||Increases loaf volume, decreases crumb hardness, anti-staling agent|
|Monoglycerides||Little to no effect on loaf volume, decrease crumb hardness, anti-staling agent|
|Increase loaf volume, decrease crumb hardness, anti-staling agent|
|Lecithin||Increases loaf volume, decreases crumb hardness, anti-staling agent|
|Polysorbates||Increase loaf volume, decrease crumb hardness, anti-staling agent|
|GMS (Glycerol monostearate)||Increase loaf volume, decrease crumb hardness, anti-staling agent|
|PGEF (polyglycerol esters of fatty acids)||Increase loaf volume, decrease crumb hardness, anti-staling agent|
Emulsifiers are most effective in doughs with a long fermentation time. If you just want to bake a quick bread in less than two hours, then don’t use emulsifiers. Most emulsifiers delay the onset of volume increase in bread dough so that you will end up with a denser bread if you don’t increase the proofing time of the recipe without an emulsifier. The benefit of emulsifiers is that you can proof the dough to a larger volume increase before it loses its stability. Because of its better stability, bread with emulsifiers tends to show more oven spring.
What are alternatives to emulsifiers?
Of course, I don’t have a package of DATEM or SSL at home. But DATEM is one of the major ingredients of the bread improver that I use. The easiest and most efficient way to incorporate emulsifiers in the correct quantities into your bread dough is to use an all-purpose bread improver.
Having said that, there are alternatives that you can use instead of DATEM or SSL:
- Soybean flour contains the emulsifier lecithin. Adding 0.5 to 1.5 % of soybean flour to bread dough is enough to increase the kneading time and kneading tolerance of bread dough as well as to toughen the gluten. In French baguettes, bean flour is a traditional ingredient.
- Adding 2 % of lard or shortening to bread dough works exceptionally well in combination with soybean flour. Actually, emulsifiers were introduced into the bread-making process as an alternative to lard. But they are not just alternatives to each other. Lard and emulsifiers work perfectly in synergy. What is important is that you use a fat that is solid at room temperature. Liquid vegetable oil does not have the same effect as lard or shortening because it contains no fat crystals. Fat is a hydrophobic ingredient so that it is present at the gas-aqueous dough interface. The crystalline fat stabilizes the gas bubbles together with the gluten and emulsifiers. Liquid oil cannot stabilize foams! You know this from whipping cream. If you heat your cream to a light simmer and then try to whip it, it won’t work. You have melted all the milk fat crystals! Fridge-cold cream with a high crystalline fat content is easiest and best suited for whipping because the crystalline fat stabilizes the gas bubbles. If you see a recipe that calls for vegetable oil then consider replacing it with lard or shortening and you will be amazed by the result.
- Lipase enzymes have been getting more popular among bakers and the food industry in recent years because they don’t have to be declared on the ingredient list. Enzymes are seen by the EU law as a processing aid and not an ingredient because they get inactivated during baking. Some consumers freak out, for no good reason, if they see DATEM or other emulsifiers on the ingredient list of their bread. This is a result of the horrible journalists in Germany who make up a lot of things that are not true about the food industry. It sells well and is sensationalist to tell people that the food industry harms their health with emulsifiers and enzymes but it is also pseudoscience and not the truth! There are no proven negative health effects of DATEM or the lipase enzymes used in bread making. The function of lipases is to cleave lipids that are detrimental for bread foam stability into mono- or diglycerides, glycerol, and free fatty acids. Mono- and diglycerides are surface-active ingredients that work in a similar way as DATEM. So instead of adding surface-active ingredients (emulsifiers) to bread dough, the lipase enzymes simply generate them by cleaving the endogenous wheat lipids in the dough. Lipase enzymes can therefore be used as a “clean label” substitute to DATEM.