Adding the barley flour after the wheat part of the dough had finished rising and the gluten matrix was fully developed provided excellent results. Photo: Jon-Are Berg-Jacobsen/Nofima

Project Year 2016

Developing health-promoting bread

Knowledge about function and stability of beta-glucan in dough systems helped Nofima scientists to develop breads for lowering cholesterol.

Scientists in the four-year research project Optifiber have investigated what happens to barley and oat beta-glucan in the bread baking process. They have then applied this knowledge to come up with both a bread recipe and a new baking process that preserve as much of the beta-glucan size as possible.

It took a long time to find the baking method that results in the healthiest bread. The main challenge is that betaglucan molecules are easily broken down, reducing their health-promoting effect.

First the scientists experimented with different recipes to find a tasty bread made with 40% barley. This recipe was then used to test a number of alternative baking processes.

Rising creates problems

“During rising, enzymes that are naturally present in grains start breaking down the beta-glucan molecules. We therefore reduced the amount of time that the barley flour is in contact with water, but always with a clear focus on ensuring good bread quality,” says Nofima scientist Anne Rieder.

Adding the barley flour after fermentation of the wheat part of the dough provided excellent results.

Finely ground, coarsely ground or flakes?

The scientists also examined how flours with different particle size affect the molecular weight of the beta-glucan and the quality of the bread. The results are clear: the larger the particles of the barley ingredient, the higher the molecular weight of the beta-glucan in the bread. Barley flakes provided the largest beta-glucan molecules in the finished bread.

The next question the scientists need to answer is whether the beta-glucan in large barley particles is as available in the small intestine as the beta-glucan in smaller particles.

“In order to be able to claim that a bread ‘lowers cholesterol’, the final product must contain at least 1 g of beta-glucan per serving. Our experiments show that it is fully possible to bake barley bread with a high enough beta-glucan content and satisfactory bread quality,” concludes senior scientist Svein Halvor Knutsen, who is project manager for the Optifiber project.

We are now working on how chain length can be a defined quality parameter for health benefits.

Research Funding for Agriculture and Food Industry and participating companies

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