Influence of fertilization in total polyphenol content in aniseed post-distillation waste material

Anise (Pimpinella anisum L.), is a herbaceous plant from Apiaceae family. Its fruit is used in the pharmaceutical industry and in everyday nutrition because of its numerous benefits. It contains essential oil with trans-anethole as the main compound, which gives it that characteristic aroma. However, essential oil content in aniseed ranges around 3-4%, and the large amount of post-distillation waste material remains unused, but it can be a potential source of biologically active compounds. The aim of the present study was to investigate the total polyphenol content and antioxidative activity of anise post-distillation waste material, as well as the influence of fertilization on it. For this investigation the anise was grown during 2013, with the application of six different fertilization regimes (control, Slavol, BactoFil B-10, Royal Ofert biohumus, vermicompost and NPK). The content of total polyphenols remains after Clevenger oil distillation was determined by using Folin-Ciocalteau reagent, and expressed in mg/g gallic acid equivalents to dry extract (GAE). Further analysis of anise extracts was performed by LC-DAD-MS for identification phenolic compounds. Capacity of neutralization of free radicals samples was determined by DPPH method, and results are expressed in mg/mg Trolox equivalent to dry extract (TE). The results indicated that fertilization significantly increased content polyphenols total in anise post-distillation waste material, from 20.0 to 26.4 mg/g, in comparison to the control (11.6 mg/g). Hydroxybenzoic and hydroxycinnamic acids and their derivatives were identified in anise post-distillation waste extract, as well as flavanone and flavonol glycosides and trihydroxy flavonol derivates. However, antioxidant activity of all anise extract according to DPPH method is poor, and EC50 value ranges between 0.04 and 0.05 TE.