The functional food production: Application of stinging nettle leaves and its extracts in the baking of a bread

•Bread was baked with stinging nettle leaves and its extracts.•Extract gained by microwave extraction was used for the first time for this purpose.•Chemical profile and biological activity of a bread was assessed.•Microwave extract successfully substitute leaves in the food formulation. Stinging nettle is an annual plant. This plant is known for applications in folk medicine, and as the human diet. The stinging nettle leaves has been used to obtain extracts, which are expected to be with a high content of biologically active compounds. Prepared microwave extracts were applied in the formulation of the functional products. The article completes preparation of the bread with addition of the stinging nettle leaves and its extract, and bread’s composition in phenolic acids, flavonoids, micro elements, and macro elements. The biological activity of the prepared bread samples showed significant antioxidant activity. This was especially true against DPPH radicals. It has been shown that it holds a high cytotoxic activity. Leaves themselves decreased the quality of the bread, while the extract improved the quality. It was sensorially confirmed. The article concluded that the extract substitutes leaves in bread as a product of a high benefit.