In this paper, there were compared the content of dietary fibre (including pentosans) and the content of biologically active compounds, i.e. polyphenols and alkylresorcinols, in rye bran, rye flour, corn grits, and in the extruded products, such as snacks, manufactured from these raw materials. It was proved that the manufactured extrudates contained a higher level of pro-health ingredients if compared with the raw materials, namely: the content of the soluble dietary fibre and pentosans was twice as high as in the raw materials; the content of alkylresorcinols was 2 to 3 times lower, and the antioxidative potential and content of polyphenols were significantly higher.