Post-harvesting of Solanum paniculatum L. leaves. Part II: Antioxidant activity and chemical composition ¹

Pós-colheita de folhas de Solanum paniculatum L. Parte II: Atividade antioxidante e composição química

ABSTRACT

‘Jurubeba’ (Solanum paniculatum L.) is a medicinal plant used in traditional medicine for liver problems, in addition to being used as a cholagogue, emmenagogue, healing agent, febrifuge, anti-inflammatory, antipyretic, tonic, decongestant, diuretic and against inappetence. Thus, the objective of this study was to evaluate the antioxidant activity, concentration of phenolic compounds and total alkaloids of aqueous extracts prepared from ‘Jurubeba’ leaves subjected to drying. ‘Jurubeba’ leaves were dried at different temperatures (40, 50, 60 and 70 °C) and velocities (0.4 and 0.8 m s^-1) of the drying air. Aqueous extracts of the leaves, subjected to drying, were evaluated by absorbance reading in a spectrophotometer. Increase in drying air temperature reduced the contents of total phenolics and total alkaloids of the leaf aqueous extracts, whereas increment in air velocity increased the concentration of these substances. Antioxidant activity was not influenced by the increase in air temperature at air velocity of 0.4 m s^-1, but under air velocity of 0.8 m s^-1 there was reduction with increasing temperature. Drying of ‘Jurubeba’ leaves can be carried out with temperature of 40 or 50 °C and drying air velocity of 0.4 m s^-1.

Key words:
total alkaloids; phenolic compounds; aqueous extract; ‘Jurubeba’