Bread from a bakery
Cooking Knowledge, Non Recipes

What even is the point of baking enzymes?

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In its simplest form, bread has just three ingredients: flour, water, and salt. That is if you’re baking artisanal sourdough bread. Non-sourdough bread includes yeast as the fourth ingredient. There are also other ingredients that can be used in bread baking to alter the texture of the final product.

Fat strengthens the gluten network and makes the final product less chewy and more tender. Sugar gives the bread a crispier crust. And malt lends a good taste and makes the bread airier.

But what is malt? It’s one of the oldest dough improvers in the world. There is pure barley malt but traditional German malt is made from a mixture of wheat and barley. Fresh wheat and barley berries are allowed to germinate. This increases the enzyme activity in grains.

Barley plant on the field
Barley berries contain enzymes that break down starch into maltose.

An important function of enzymes is that they cleave larger molecules into smaller molecules. As you might know, wheat and barley contain a large amount of starch. During germination of the grain, the amount of starch cleaving enzymes increases, and thus some of the starch in the barley berries gets converted to maltose while some of the starch in the wheat berries gets converted to glucose.

The germinated wheat and barley berries then get dried and milled to produce malt flour. This malt flour keeps for a long time and gets used extensively in German bakery products. It can either be sold enzymatically active or enzymatically inactive. The enzymatically inactive powder has usually been heated above 100 °C to inactivate the enzymes. It’s added to bread just because it tastes good. For example, my German bread roll recipe calls for enzymatically inactive barley malt.

How enzymatically active malt improves the bread quality

More interesting is the enzymatically active malt. The starch cleaving enzymes in this powder are still “alive”. Their activity gets reduced to a minimum by the drying process. Enzymes need free water around them to catalyze chemical reactions. Once the malt is added to bread dough, the malt rehydrates and the enzymes become active again.

These enzymes break down some of the starch in the flour to produce sugars that get consumed by the yeast. Thus more carbon dioxide gets produced and the bread dough rises quicker and the bread turns out airier. Any leftover sugar in the dough is also great because sugar gives the bread a golden-brown crust.

If you’re baking a quick bread with short fermentation time, it’s always advisable to add some sugar to the dough to enhance browning. On the other hand, if you’re working with a poolish or overnight fermentation, you don’t need to add any sugar. There are starch-digesting enzymes in the flour that will break down the starch into simple sugars over time. Some of them will be consumed by the yeast to produce carbon dioxide while others will remain in the dough to darken the crust.

Breakfast bread rolls
German bread rolls often contain malt powder.

Yeast cannot consume starch. It can only eat sugar. With this fact in mind, it becomes quite obvious why enzymatically active malt powder makes bread airier. You have much more starch-digesting enzymes in your bread dough. Thus the bread rises quicker and the yeast has more food. More food for the yeast = more gas in the dough = airier bread.

Proper German bread rolls almost always include malt powder. Different from a baguette, they are only fermented for a short time. To get them airy and light in this short time, sugar and malt need to be added to the dough. Otherwise, you end up with dense bread rolls.

Malt powder is just one of many baking enzymes

Of course, the naturally occurring enzymes in malt aren’t by far the only enzymes bakeries add to their products. Almost all bakeries around the world use dough improvers to bake bread to a certain quality standard. It doesn’t matter if you’re eating an American bagel, German bread roll, or East Asian sandwich baguette. It’s almost 100 % certain that enzymes have been used for its production.

In the European Union (EU), baking enzymes don’t have to be declared on the ingredient list. They are seen as a processing aid under EU law because they get destroyed by the high heat in the oven. Thus they serve no purpose in the final product. So even if no baker likes to admit using them, baking enzymes are very common even in small artisanal bakeries.

Bakery factory
The food industry heavily relies on baking enzymes but they are also used by artisanal bakeries.

You don’t need enzymes to bake good bread. For an experienced baker, it’s no problem to bake tasty bread without enzymes. However, as you might know, there’s quite a shortage of qualified workers in bakeries because the job of a baker is a very unpleasant one. You have to get up early in the morning and the pay is shit.

I don’t want to say that baking enzymes are a bad thing. They have their place in traditional baking and I like to use baking malt extensively too. However, way too often nowadays baking enzymes are used to conceal a product of low quality. They are not used to improve an already good product.

Instead, they are used to cut down costs. That is mainly achieved by reducing the fermentation time of the bread. Time is money. Adding to that, baking enzymes make the dough more machine-friendly. Thus, you don’t need a skilled baker to, for example, shape a loaf of bread.

But how do enzymes help large bread manufacturers with the production process? The company Novoenzymes offers seven different enzyme solutions for bakers to achieve:

  • Better freshness (soft, elastic, moist bread)
  • Dough strengthening (increased bread volume, open crumb)
  • Dough conditioning (smooth dough handling, better bread volume)
  • Gluten strengthening (dough is less sticky)
  • Appealing appearance (crispier and darker crust formation)
  • Flour correction (to standardize the flour to get consistent results)
  • Reduced acrylamide (to comply with local regulations, acrylamide is carcinogenic)

How enzymes keep bread fresh for longer

Especially white bread can get stale very quickly. That is mainly because the starch in the bread dough recrystallizes after baking. This process is called retrogradation. Crystalline starch can hold less water than gelatinized starch and thus the bread dries out and gets rigid.

Bread during storage
The starch in bread recrystallizes during storage which leads to a loss of water.

You can also observe this process with starch-thickened sauces. If you mix starch with cold water, you will notice that starch is insoluble in water. However, if you heat the starchy water up, it will thicken at about 60-70 °C. This process is called gelatinization. The starch gels and can suddenly be dissolved in water. That is because the starch loses its orderliness at high heat and thus water molecules can be entrapped inside swollen starch granules. Once the starch paste gets cooled down to room temperature, the gelatinized starch will slowly recrystallize and thus lose its water-holding ability over time. You will see water leaking out of the starch paste.

The cooler it is, the quicker the recrystallization process. Bread loaves that are stored between -7 to +7 °C (20 to 50 °F) get stale three times quicker than bread that is stored at room temperature. So never put your bread in the fridge. Leave it on the counter or freeze it if necessary.

The enzyme solution to produce longer-lasting bread is called maltogenic alpha-amylases. Maltogenic enzymes can keep the bread from staling for up to 1 month of storage time. There are three different mechanisms on how maltogenic alpha-amylases keep bread fresh for longer:

  • They decrease the starch retrogradation
  • They decrease the rigidity of the starch network
  • They decrease starch/protein interactions

The most important point here is the decrease in starch retrogradation. Alpha-amylases modify amylopectin molecules (a starch component) to generate water-soluble sugar molecules. In the case of maltogenic alpha-amylases, these sugar molecules are mainly maltose. However, it’s not the maltose that makes the bread last longer. Through this enzymatic cleavage, the amylopectin’s primary structure is modified but still kept intact. This modified structure prevents the starch from recrystallizing. The reason why this modified starch recrystallizes much slower is unknown.

Molecular structure of starch.
Starch is a large chain of glucose molecules that can either be linked linearly to form amylose or 3-dimensionally to from amylopectin.

Another minor effect is that this modified starch shows a low interaction rate with the gluten proteins in the bread. During bread staling, the gluten and starch like to form starch-gluten complexes which have a decreased water-holding capacity and thus make the bread hard and brittle. Alpha-amylases prevent that from happening.

It’s not just enzymes that can keep loaves of bread from going stale. If you’re not using alpha-amylases you can also add the following ingredients to bread dough to keep it fresh for longer:

  • Pentosanes are indigestible carbohydrates present in whole wheat (2-3 %) and rye berries (6-8 %). They can hold six to eight times their weight in water. They act as a water sponge. This is why whole wheat and rye bread keeps fresh for longer than white bread and why you can add more water to doughs made from rye or whole wheat flour.
  • Emulsifiers like egg yolks form complexes with starch molecules and thus retard the retrogradation process.
  • Salt. Salt is a hygroscopic material. Just like pentosanes, it helps the bread to hold onto water for a longer time.
  • Modified starches. If you don’t want to modify the starch yourself with enzymes you can also buy a pre-modified starch that will trap water and hold onto it.

How to strengthen bread dough

Every home baker knows that bread dough needs to be handled gently. The only time you really apply a lot of strength and energy is during the kneading phase. But when shaping the dough, you have to work gentle and fast.

But especially machines or unskilled workers might not be good at shaping a baguette or pretzel. Misshapen bread needs to be discarded because no consumer will buy a deflated flatbread. Dough-strengtheners make it easier to shape a loaf because the dough is firmer and more forgiving. It will also hold its shape better when baked in the oven and entrap more air.

Freshly-baked baguettes
Shaping and scoring baguettes is not so easy as the dough is very soft.

Traditionally, emulsifiers like lecithin from egg yolks or soy protein have been used to strengthen bread dough. Emulsifiers in bread are usually not added because of their ability to combine oil and water. Instead, they are added because they improve the binding of the gluten strands leading to a more robust gluten matrix that doesn’t collapse and deflate so easily. Like so many other things, it’s still unknown why they toughen the gluten network.

However, nowadays you can also use enzymes to strengthen the gluten network. Phospholipases have a similar effect on bread dough as traditional emulsifiers. Phospholipids are minor components of wheat flour. By cleaving these phospholipids with phospholipases their structure gets modified so that they can act as natural emulsifiers.

Lipid cleaving enzymes are also used in noodle production to decrease the stickiness of dried noodles. As you might know from my post about how noodles are made, only high-quality durum semolina is suitable to produce dried pasta of good quality. That’s why Asian noodles are usually sold fresh. They are made from soft wheat flour.

The exact mechanism of why lipases have a firming effect on wheat-based noodles is still unknown. They somehow inhibit the swelling of starch granules during cooking and thus prevent amylose (a starch component) from leaching out to the pasta surface and into the cooking water. The noodles are thus less sticky and retain a nice bite. By adding lipases, dried noodles of good quality can be produced from poor-quality soft wheat flour.

How enzymes improve the dough condition

Dough conditioners are of primary interest to big industrial producers. As you might know, wheat flour is a natural ingredient that fluctuates in quality. Depending on its origin and storage you can, for example, have a different protein, starch, or moisture content.

White flour on a table.
An important task of every baker is to assess the quality of his flour used.

A lot of people who don’t understand baking say that it is an exact science and that you need to follow measurements and times given in recipes. But this is a recipe for disaster. Baking is much more about feel and experience than cooking.

It doesn’t make sense to learn baking by following recipes. You need to work with the dough by hand and develop a feel for it. You need to be involved in the process. You need to feel when the dough is kneaded sufficiently or when it is ready to go in the oven.

The only reason why bread factories can work with standardized recipes is that they work in a controlled climate and because they use dough conditioners. Unless you own a professional bread factory, you need to work by feel when baking bread.

The two most common dough conditioners are:

  • Cellulases that break down the cellulose which is found in the wheat bran. In whole wheat flour, cellulose binds water and thus inhibits the gluten network formation. If this bound water is released, it can help form a better gluten network.
  • Xylanases that break down arabinoxylans and pentosans. These indigestible carbohydrates bind water. On the one hand, this is positive because the bread will keep fresh for longer with higher water content. However, arabinoxylans and pentosans also compete with the gluten proteins for water which inhibits the gluten network formation. If they are broken down, water gets released so that a stronger gluten network develops.

How to strengthen the gluten network directly

Besides breaking down indigestible carbohydrates, another way to strengthen the gluten network is by adding an enzyme called glucose-oxidase to your dough. Glucose-oxidase catalyzes the oxidation of glucose to gluconic acid and hydrogen peroxide. Hydrogen peroxided is a strong oxidant that thus oxidizes the gluten network. This leads to an increased formation of disulfide bonds within the gluten network so that you end up with a stronger, more cross-linked gluten network.

Bread crumb.
A well-developed gluten network allows bread loaves to entrap more air.

Hydrogen peroxide also protects the gluten network. The natural-occurring antioxidant glutathione has a softening effect on the gluten network. By oxidizing glutathione with hydrogen peroxide, this effect gets suppressed.

You might know that Vitamin C (ascorbic acid) is often added as an oxidizing agent to doughs to act in the same way as hydrogen peroxide. Now, if you have a chemistry background, you might insist that Vitamin C is a reducing rather than an oxidizing agent. That is certainly true. However, there are ascorbic acid oxidase enzymes naturally occurring in flour which oxidize the ascorbic acid to dehydroascorbic acid. This dehydroascorbic acid then acts as an oxidant in the same way as hydrogen peroxide does.

Another good way to improve the gluten network strength is to simply add pure vital wheat gluten to the dough. However, this is not the preferred way by the industry because vital wheat gluten is more expensive than Vitamin C or enzymes. But if you only have access to poor quality flour where you live, this is the way to go for home bakers.

In some products, like pastries, you might want to have the opposite effect. Biscuits, cakes, or cookies are often required to be brittle and crispy or very tender and soft throughout. You might know that for example for shortcrust pastry it is very important to not knead the dough so that the gluten network doesn’t get developed. There are proteolytic enzymes available for sale that cleave gluten proteins and thus reduce the strength of the gluten network. This prevents pastries from turning out rubbery or chewy.

Enzymes that break down gluten can be used to improve the texture of cookies.

How to improve the appearance of bread

With the appearance, I’m talking about the color and crispness of the crust, not about the shape and scoring of the bread. As a general rule, sugars give bread loaves a beautiful crust. So the simplest solution to the problem of a pale crust is to add sugar or baking malt into your dough. Otherwise, you have to let the dough ferment long enough for the natural-occurring enzymes to break down enough of the starch into glucose.

Industry-manufactured bread is usually fermented over a short period of time. Wheat flour doesn’t contain enough natural-occurring enzymes to give you a beautiful dark crust in less than one hour. However, you can add for example glucoamylases to the dough. These enzymes cleave glucose molecules off starch chains. The more glucose is in the dough, the more browning occurs and the faster the dough rises because the yeast has more sugar to eat. Baking malt, for example, contains natural amylases.

Most industrial bread manufacturers don’t like to add baking malt to their products because the enzyme activity in baking malt is inconsistent. You never know exactly how many active enzymes it contains. After all, it’s a natural product, just like wheat or rye flour. It’s much easier to use biotechnologically produced amylases because they can be added to the dough in strictly defined quantities.

How enzymes can be used to produce healthier bread

As you might know, the Maillard reaction, the non-enzymatic browning of foods, not only creates flavor compounds but also carcinogenic molecules like acrylamide. In the Maillard reaction, sugars react with amino acids to give the bread a golden-brown crust while it bakes.

Bread is one of the foods which is unfortunately high in acrylamide. The darker the crust, the more carcinogens bread contains. However, there are enzyme solutions to lower the amount of acrylamide in bread by up to 95 %.

A dark bread crust looks beautiful and adds a lot of flavor to bread but it can also contain large amounts of acrylamide.

Asparaginases convert the amino acid asparagine into aspartic acid. Acrylamide is usually formed as a by-product of the reaction of sugar with asparagine. If there is no asparagine in the dough, there is no formation of acrylamide. This a great innovation as the bread will still develop a dark golden-brown crust yet it is almost completely free of acrylamide.

Baking enzymes are neither unnatural nor evil

A lot of people, especially in Germany, claim that baking enzymes are “unhealthy” or “unnatural”. But I hope that I might have demystified this topic a little bit. Enzymes have been used in baking, in the form of baking malt, for hundreds of years. They are by far no recent invention.

Enzymes don’t magically make bread airy and moist. They are not the key to bake tasty bread. But they can make it easier for anyone to achieve better results. The main functions of enzymes are to increase the shelf-life of the bread and to compensate for bad ingredients, short fermentation times, and bad technique.

A lot of people in Germany make the mistake that they buy the cheapest flour available in the supermarket. And then they wonder why their dough is horribly sticky to work with and-the bread comes out much denser than on the recipe picture.

The first step in baking good bread is buying fresh high-quality flour from a local mill. This flour will have sufficient gluten and enzyme activity to bake tasty bread. It will hold more water than cheap flour and make doughs much more pleasant to work with. Flour is nothing to cheap out on. It’s the most essential ingredient in baking bread.

Wheat berries getting harvested
The quality of wheat can vary immensely.

Can you still bake bread with cheap low-quality flour? Yes, sure. With experience, you might be able to handle a sticky dough and stabilize it. And if you use enzymes you can standardize the flour to a specific quality level. But why would you bother doing that at home? Just buy a good-quality flour. That’s much easier.

Enzymes can be a big help to home bakers

To achieve a better bread volume and crust you can use enzymatically active baking malt or commercial dough improvers. These are ingredients I can highly recommend to anyone. If you have an enzymatically active malt powder or a dough improver, you will be able to produce bread rolls as light as the ones you know from the food industry. Of course, the industry makes the bread airy because they want to sell you air and water rather than wheat. But if you strive to achieve an open and fluffy crumb, this is the way to go.

Kneading bread dough by hand.
Baking good bread takes experience and feel.

I often use enzymatically inactive malt because I like the flavor but want my bread to have some substance. I’m not so crazy to bite into a piece of air. I don’t know if you’re familiar with the mini-baguettes they eat in Cambodia or Vietnam. It’s basically a tasteless French baguette that is pumped full of baking enzymes. It’s so light and the crumb is so tender, it collapses into nothing if you dip it in a soup. It’s nice if you just want to eat it as sandwich bread for more flavorful ingredients. But I would never eat that with just butter on it. A true French baguette or German bread, however, can stand for itself.

You should never forget that baking high-quality bread takes practice and experience. A good baker needs to be able to judge the quality of the raw ingredients, the consistency of the dough, and the moment the bread is ready to bake by experience and feel. No machine or food engineer with only theoretical knowledge can beat a professional baker. So don’t be disappointed if your bread isn’t always perfect. It takes some time to get the hang of it. Improving your bread baking technique over time will have just as much impact on the quality of the bread you bake as any enzyme available on the market.

That was a lot of theory today. Next week I will show you how to use baking enzymes and how big of a difference they can really make.

Resources:

Staling of white wheat bread crumb and effect of maltogenic α-amylases. Part 1: Spatial distribution and kinetic modeling of hardness and resilience

Prüfungsfragen für Auszubildende als Bäcker, Konditor, Bäckereifachverkäuferin

Emulsifiers in bread making

Phospholipase Using as Breadmaking Improver

Enzymes solutions for baking

Brot, Backwaren und Hilfsmittel für die Bäckerei

Effect of alpha-amylases from different sources on the retrogradation and recrystallization of concentrated wheat starch gels: relationship to bread staling

Kennzeichnung von Enzymen

Role Of Salt In Bread Baking

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