There are a number of different dough conditioners that can be used, including:
Alpha-amylase: These break down damaged starch into smaller sugar units, which are consumed by yeast during fermentation to produce carbon dioxide (CO2). Amylases help optimize the dough’s gas production, which improves loaf volume and enhances crust colour.
Xylanase: These break down insoluble cell-wall compounds in the flour and create soluble fragments while releasing bound water into the dough for better gluten hydration. Xylanases enhance network formation in the dough and have a strengthening effect. They improve dough tolerance and machinability, resulting in improved loaf volume, crumb structure and softness.
Hemicellulase: These break down the hemicellulose or pentosans in flour, which releases bound water into the dough for better gluten hydration. They improve dough machinability (dough is made more 'machine-friendly') and help improve loaf volume and crumb structure.
Glucose oxidase: This dough additive causes a reaction that forms linkages in the dough’s gluten network. Glucose oxidase adds strength to the dough and makes it drier, which can help improve bread volume and result in a more uniform bread crumb.
Lipase: These break down fat in the flour to produce mono- and di-glycerides. They are recommended for use in bread formulations that have lower fat levels. Lipases improve dough strength and can help improve loaf volume and crumb structure.
Lipoxygenase: These break down fats in the flour that give pigments to the dough. They help improve crumb colour by making it whiter.
Maltogenic alpha-amylase: This converts the starch into forms that resist firming (staling in the bread), which can make the bread softer over its shelf life (anti-staling agents).
Dough conditioners are divided into four groups:
Reducing agents: These break down the linkages in the gluten network and make the dough weaker (more extensible and less elastic). They are typically used to reduce dough mixing time in commercial bakeries. Common types include L-cysteine and inactive yeast (glutathione).
Emulsifiers: These are fat-based ingredients that function as dough strengtheners and crumb softeners. Dough-strengthening emulsifiers (such as Diacetyltartaric acid esters of mono- and di-glycerides (DATEM), Sodium stearoyl lactylate (SSL)) interact with the gluten network and make it more elastic and more extensible, which results in dough that is less susceptible to breaking when exposed to mechanical stresses (adds to its tolerance). They not only improve the strength of the gluten network but can also improve loaf volume and produce a finer crumb structure. Crumb-softening emulsifiers (such as Monoglycerides) bind with the gelatinizing starch during baking, which prevents the crumb from firming as the bread ages. The result is improved crumb softness.
Oxidants: These form linkages in the gluten network, which makes the dough stronger (less extensible and more elastic). Common types include ascorbic acid.
Vital wheat gluten: This increases the protein content of the flour and helps with gluten network formation. Vital wheat gluten can improve the tolerance and strength of the dough, which can improve loaf volume, produce stronger sidewalls and increase crumb strength.