Extraction of Phenolic Compounds with Antioxidant Activity from Beetroot (Beta vulgaris L.)

Background: Beetroot is reported as an important source of polyphenols as well as betalains, which are compounds that possess high antioxidant effect and radical scavenging capacity. Objective: The present study aimed at identifying the most suitable extracting parameters to attempt maximizing the recovery of phenolic compounds with antioxidant activity in beetroot. Methods: Grounded beetroot was used to perform extractions with different aqueous solutions (ethanol at 50% and acetone at 60%), for different times (15 and 60 min), using different volumes of the extraction solution (25 and 50 ml). For each of the combinations three successive extraction steps were performed and in each extract were quantified the Total Phenolic Compounds (TPC), the anthocyanins (ANT) and the antioxidant activity (AOA), all by spectrophotometric techniques. Results: The results indicated the usefulness of using three successive extraction steps over the same sample besides clearly indicating clearly that an extraction time of 15 min was sufficient. It was further observed that 50 ml of extraction solvent were preferable than 25 ml and the best solution was acetone at 60%. The TPC in the fresh beetroot varied from 1.45 to 2.70 mg GAE/g, the ANT from 0.23 to 0.77 mg Mv3G/g and the AOA from 13.9 to 19.9 μmol TE/g. Conclusion: It was concluded that the method of using three successive extraction steps of 15 minutes each was appropriate to increase the recovery of phenolics with antioxidant activity from beetroot.