Effect of drying on the phenolic content and antioxidant activity of thistle flower

The thistle is a plant that is associated with the production of cheese, as it is responsible for the phenomenon of coagulation of milk. Lately there has been an increased the number of studies about this plant, related to the chemical composition in order to perceive the benefits for human health. The aim of this study was to characterize the thistle flower in relation to its composition in phenolic compounds and also evaluate its antioxidant activity. For that, were studied samples of thistle flower from species Cynara cardunculus L. after freeze-drying and convective drying at different temperatures (40 ºC, 50 ºC and 60 ºC). After each treatment were made from each sample two successive extractions with solutions of methanol (98% v/v) and acetone (60% v/v). The extracts were then used for characterization of the samples in phenolic compounds and determination of antioxidant activity. The results showed that the amount of phenolics and antioxidant activity in the flower thistle varies depending on the drying temperature decrease occurring as they use higher drying temperatures