Abstract

In this work, a liquid extract obtained from leaves of Rhus coriaria L. has been studied in terms of its tanning capacity. The extract was quantified with 25.59% of tanning matter. The hide powder assay gives us two analytical solutions, corresponding to tannin and non-tannin matter portions. Both solutions were analysed by UV-Vis spectrophotometry and high performance liquid chromatography, the results show in both cases that around 97% of the matter present in the extract has a tanning effect. The antioxidant activity of the extract is studied in relation to chromium VI formation in sheepskrns. The exposure to UV light of the skins not retanned with sumac extract showed a marked increase in chromium (VI) content, therefore this extract acts as a powerful antioxidant agent. With only a 0.7% of the tannin matter used during the retanning process the chromium (VI) content is reduced by about 65%. An application of 4.2% of tannin matter makes chromium (VI) undetectable.