Acta Scientiarum Polonorum Technologia Alimentaria

Abstract The aim of the study was to check the influence of extrusion on the content of polyphenol and antioxidant/antiradical activity of rye grains. The extrudates prepared from three cultivars of rye were obtained at different process parameters. Total polyphenol, antioxidant and antiradical activity was measured in the samples. Extrusion resulted in a decrease of total polyphenol content (TPC) on average by 40% in rye grains, and the largest loss of endogenic phenolic compounds was observed at the extrusion conditions: 20% moisture of raw material and 120°C. Extrudates obtained at: 14% moisture of raw material and 180°C exhibited either increase of these compounds or no change. It was found that rye extrudates exhibited the highest antiradical activity (measured by the methods with DPPH and ABTS) when raw material contained 14% of moisture and at temperature of the extrusion – 180°C, while the lowest when the parameters were 20% and 120°C. Antioxidant activity in beta-carotene-linoleate model system was high when rye extrusion was performed at 14% and 20% moisture and temperature 180°C. The negative influence of extrusion on the antioxidant activity of rye grains was observed at 20% moisture and 120°C.