Rye bread, wheat bread and sourdough bread are probably what we most often think of when we think of bread in Denmark. We are used to bread made from either rye, wheat or a mixture in which wheat is almost always included. Wheat has really good baking properties. It makes light and airy bread with a deliciously crisp crust. However, according to researchers at Aarhus University, we should look to the barley fields when baking the bread in the future. 

"There are several good reasons to eat barley bread. When we grow barley, we use less nitrogen than when growing wheat. This means that the amount of fertiliser that could potentially lead to leaching of mineral nitrogen to water bodies or as greenhouse gases to the atmosphere is reduced. In concrete terms, farmers in Denmark are allowed to use up to 240 kg of nitrogen per hectare when growing wheat, meanwhile they are only allowed to use 140 kg per hectare when growing barley. This is a relatively large difference. However, it should be noted that winter wheat usually yields slightly more than barley, which is typically grown as a spring crop," says Associate Professor Kim Hebelstrup from the Department of Agroecology at Aarhus University. 

When people talk about climate, they think of climate change. Here too, barley has an advantage over wheat. Barley is what is known as stress tolerant. Although wheat can tolerate quite a lot in terms of drought and fluctuating temperatures, barley has proven to be even better at adapting to different weather extremes. 

"Barley flour may also be an advantage in the current situation we find ourselves in worldwide. After all, we are currently seeing how international conflicts can limit the market for wheat for breadbaking. If Danish barley flour can achieve a very high quality that makes it attractive to consumers, we could potentially become less dependent on importing wheat," says Kim Hebelstrup. 

From feed to food

Today, barley is mainly used for animal feed, and partly as malting barley in beer production. The idea behind the new project, called "Barley: From feed to food", is to be able to bake bread from barley. 

"The problem is that barley doesn't have very good baking properties. If you bake a loaf from barley flour alone, you'll end up with a loaf that's very compact and hard like a cannonball. We want to find out why you can't use barley to bake bread, why does the flour have such poor baking properties and what can we do to solve that problem?" says Kim Hebelstrup. 

The researchers have a hypothesis about why barley is so bad to bake with. Based on wheat's well-studied baking properties, it is known that not all wheat varieties are equally good for baking. 

"In the analyses of wheat, it has been found that the baking properties are related to the proteins of the grain, which in wheat are mainly the gluten proteins. They help to create the stretchability and elasticity needed to make good bread with a good crumb structure and a high volume. And we can see that barley has a completely different protein network than wheat," explains Kim Hebelstrup. 

Analysing barley protein

The project is a collaboration between the Department of Agroecology and the Department of Food, both from Aarhus University. 

"My colleagues Lotte Bach Larsen and Søren Drud-Heydary Nielsen from the Department of Food have developed a method that can analyse protein networks in milk. We want to use this method to measure the protein network in barley, so that we can map different barley varieties for baking properties. These chemical analyses of flour and dough are complemented by baking experiments in Ulla Kidmose's research group, also at the Institute of Food." says Kim Hebelstrup.

The aim is to find an explanation for why the proteins in barley fail to create the same stretchability and elasticity as wheat. This will help explain why barley is not so good to bake with. The aim is to point researchers in the direction of a solution to the problem. 

"Once we know the cause of the problem, it will also be easier to investigate possible solutions. We hope to achieve this in future projects," says Kim Hebelstrup. 

Barley stabilises blood sugar

The project is important not only for the environmental and climate reasons already mentioned. Barley has health-promoting properties. Indeed, there is existing published data pointing to barley's ability to control blood sugar levels to a greater extent than wheat. 

"In another study, this data has been extended with a clinical trial with diabetic patients. This study was conducted by Mette Bohl Larsen, Søren Gregersen and Kjeld Hermansen at the Department of Endocrinology and Internal Medicine, Aarhus University Hospital," says Kim Hebelstrup. 

The results of this study are about to be published.