Wheat flour is the basis of most bakery goods. The ability to create a viscoelastic dough that can contain gas produced from yeast and thereby produce a loaf with an aerated crumb is unique to wheat. It is the way the gluten proteins function that gives wheat this property. Both the quantity of gluten protein and the composition of the gluten proteins are important for the baking properties of wheat flour. Variations in the protein composition affect the functional properties of the dough and the quality of the end product and are of great significance for the milling and baking industries. Nofima Mat has extensive competence in the functional properties of gluten and has been studying variations in these properties for many years. Recent research has shown that both genetic and environmental factors affect the protein composition and the structure of the gluten proteins through the grain. Variation in quality presents a challenge to the milling and baking industries. We are working on understanding how variations occur, so as to be able to contribute to the breeding of varieties with a greater tolerance of environmental factors. Basic knowledge about gluten proteins as the building blocks of all wheat bakery is vital for the entire value chain.
Given a high proportion of wholemeal bread types it is especially important to have a strong gluten fraction that can carry the other cereal ingredients in the bread and ensure an airy crumb.
Barley and oats
In Norway barley is grown on almost half the area devoted to cereals and is the dominant grain type. But the use of barley in the diet is still at a very low level, equivalent to 0.7 kg per person per year. The excellence of barley lies in its cell wall. The cell walls of the endosperm consist of types of polysaccharides other than starch and in barley we find a great deal of beta-glucan in the cell walls. Beta-glucan produces a higher viscosity in the intestine, which is an important property that is linked with health benefits. Barley can contain from 3 to 11 per cent beta-glucan. We also find a high beta-glucan content in oats. Barley also contains a good deal of insoluble fibre, the main components being cellulose and insoluble arabinoxylane. Insoluble fibre has beneficial health effects, but works in a different way to the soluble beta-glucan. We also find insoluble fibre in wheat and other types of cereal. Wheat bran in particular is a good source of insoluble fibre. Barley is also rich in phytochemicals, including antioxidants.
A number of surveys have showed that a higher intake of barley and oats can reduce cholesterol levels in blood, both in total and for LDL cholesterol. A higher intake of beta-glucan is probably the reason for this. Higher viscosity in the intestine caused by beta-glucan can also lead to a slower breakdown of starch and thus affect the take up of glucose. Thus products made of barley and oats that are rich in beta-glucan often have a lower glycemic index (GI).
Nofima Mat is researching into the content of beta-glucan and phytochemicals in Norwegian grown barley. These surveys have also covered the content in various fractions of barley after milling, as well as analysing the content before and after processing bread. We have learned about the varieties of barley that are best suited for use in food and also about how the growing environment can affect the beta-glucan content. The research also studies the probiotic effects of beta-glucan and other fibre components of food products and what happens as they travel through the stomach, small intestine and large intestine.
The sale of organic products, including cereal products, is steadily increasing. Nofima Mat is working on projects, the object of which is to increase the use of Norwegian grown organic wheat in bread. An increasing amount of organically grown wheat is being produced in Norway, but the grain is not reaching the organic market. In order to be able to use more Norwegian organic wheat in food there is a need for more stable quality, better use of quality control, sorting and mixing different varieties and a better understanding of how the baking process can be adapted to flour quality.