From ugly and dry to lovely and juicy
Nutritional experts say we should eat more barley and oats, as these are very good for you. However, wholemeal bread baked with oats and barley often end up ugly and dry. Researchers have now found the solution: a bit of sourdough!
Trendy bakeries have over the past years earned good money from an ancient and venerable baking tradition: sourdough bread. Sourdough is made of flour, water and lactic acid bacteria which is left at room temperature from 15 hours to several years. The lactic acid bacteria can either be added to the dough as a separate culture, or originate in the microflora of the flour.
Sourdough bread is not always healthy, however. Commercial sourdough bread often contains small amounts of wholemeal flour, and rarely barley or oats, which grain experts agree contain a number of healthy components.
Sourdough – the answer to a sour problem
Nofima Mat has promoted increased use of barley and oats in Norwegian baked goods for a long time, but this has proved to be difficult, in spite of their healthy ingredients. Baking with these grain types is harder than with wheat. The dough acts differently and gives bread with a different taste. The researchers were therefore doubly pleased when they got such good results with a number of trials involving sourdough.
"Sourdough has a positive effect on bread, particularly when it contains wholemeal flour from barley and oat bran," concludes satisfied grain researcher Stefan Sahlstrøm.
Is sourdough the solution to make all types of bread healthy and give them good taste?
"Absolutely not! But sourdough tends to improve the quality of the bread, and has a positive effect on some of the ingredients," says Sahlstrøm.
Rule of thumb: 20% of each
If you replace wheat by barley or oats in a bread dough, water absorption increases, ie. more water must be added in order to produce the same consistency as with wheat. The dough is also less stable, and needs careful kneading. If sourdough is added, however, water absorption decreases.
"We have exact measurements showing how the amount of sourdough affects various parameters in the dough," explains Stefan Sahlstrøm. "Our measurements show that sourdough must be added in moderation: using 40% flour from barley/oats without sourdough, or using as much as 40 % sourdough, will give smaller loaves and often a hard and rough surface prone to cracking. Using 20% sourdough and 20% wholemeal flour from barley and oats, however, gives loaves of a better appearance and size.
"What was surprising to us was that we could use a total of 40 per cent barley or oats in the dough, when we used part of it as flour and part as sourdough. These are good news for the baking industry, and will make it easier for them to introduce these healthy forms of grain," says the senior researcher.
Improved nutrient absorption
The baking experiments didn’t start in the bakery as you’d expect, but in experiments with mink, chicken and salmon as model animals. Sahlstrøm has tested sourdough feeds to mink, chicken and salmon, all with positive results. The digestion of the fish and animals improves, as does their absorption of carbohydrates in general and starch in particular, as well as their absorption of fats.
"We measured what was eaten and what remained after digestion. Barley feeds with added sourdough gave higher nutrient absorption," concludes Sahlstrøm.
It is highly likely that these findings also apply to humans. The fibres in barley and oats create a feeling of fullness in the stomach that lasts longer and gives energy over a longer period of time. In addition, fragments from fibres and starch stimulate the bacterial flora in the colon, and this protects against colon cancer and strengthens the immune system. Further research is currently under way to find out more about the many positive properties of barley and oats – and to make Norwegians eat more of these grain types.