Antioxidant activity is one of the most desirable properties of natural compounds. Among these substances are phenolic compounds which exhibit excellent antiradical activity. The main aim of the present study was determination of the free radical scavenging activity of gruels with 5, 10 and 20% addition of linden inflorescence. The studies were based on two methods: TLC-bioautographic assay and spectrophotometric analysis using DPPH (2,2-diphenyl-1-picrylhydrazyl radical). The obtained results indicate that the radical scavenging properties of the extracts are positively correlated with the content of phenolic compounds in gruels and that a high-temperature extrusion process does not deactivate antioxidant polyphenolic compounds.