The researchers wanted to see if they could use barley flour instead of some wheat flour to make bread in Morocco. Barley has good nutrients like fiber and vitamin E. They mixed barley flour with wheat flour in different amounts and tested how it affected the bread. They found that adding up to 20% barley flour didn't change the bread much, but adding more made the bread smaller and less tasty. However, when they used a special bread improver, the bread was better even with more barley flour. So, you can use 10-20% barley flour to make good bread, or up to 50% for bread with lots of fiber and nutrients.