Evaluation of bioactive compounds in cereals. Study of wheat, barley, oat and selected grain products

Background One of the requirements for proper nutrition and maintenance of good health is to supply the body, through diet, with an appropriately increased quantity of bioactive compounds. With this in mind, modern milling and baking industries keep introducing new types of products. The use of such additives as wholegrain flours and bran in baked products provided the basis for research in this paper. Methods The aim of the study was to conduct a qualitative and quantitative evaluation of marketable wheat, barley and oat grain, used as raw materials to produce dehulled kernels, ground grain, wholemeal flour and wheat flour type 550 (all-purpose or plain flour), as well as wheat bran. Additionally, analyses were performed to determine the chemical composition and contents of nutrients, selected bioactive compounds and antioxidant activity. Results The studied raw materials in commercial cereal differ in their chemical composition. Dehulling of wheat, barley and oat grains significantly contributed to the reduction of minerals, protein and total dietary fiber (TDF) contents, except for the amount of protein in dehulled wheat and oat grains. Oat bran, in contrast to other oat products, was characterized by the highest contents of minerals, protein, TDF, and the smallest amounts of saccharides and total starch. The lowest content of minerals was recorded in wheat flour type 550. Thermal processes affect the concentration of tocochromanols in the grain, with tocotrienols being more resistant to hydrothermal treatment than tocopherols. Grain dehulling also significantly decreased the total amount of tocochromanols in relation to the original grains. Conclusions Wheat products differ in the contents of their individual components. They are characterized by high contents of tocochromanols, phenolic compounds and water-extractable arabinoxylans, with the exception of white refined wheat flour, which is mainly a source of saccharides. In the case of barley and oat products, the analysis showed no differences between these product groups. It was also shown that dehulling of barley and oat grain causes statistically significant differences in the contents of nutrients and natural antioxidants.