Antioxidant Capacity of Nettle Leaves During Osmotic Treatment

  • Violeta Knežević Department of Chemical Engineering, Faculty of Technology, University of Novi Sad, Bulevar Cara Lazara 1, 21000 Novi Sad, Serbia
  • Lato L. Pezo Engineering Department, Institute of General and Physical Chemistry, University of Belgrade, Studentski trg 12-16, Serbia
  • Biljana Lj. Lončar Department of Chemical Engineering, Faculty of Technology, University of Novi Sad, Bulevar Cara Lazara 1, 21000 Novi Sad, Serbia
  • Vladimir S. Filipović Department of Chemical Engineering, Faculty of Technology, University of Novi Sad, Bulevar Cara Lazara 1, 21000 Novi Sad, Serbia
  • Milica R. Nićetin Department of Chemical Engineering, Faculty of Technology, University of Novi Sad, Bulevar Cara Lazara 1, 21000 Novi Sad, Serbia
  • Stanislava Ž. Gorjanović Engineering Department, Institute of General and Physical Chemistry, University of Belgrade, Studentski trg 12-16, Serbia
  • Danijela Šuput Department of Chemical Engineering, Faculty of Technology, University of Novi Sad, Bulevar Cara Lazara 1, 21000 Novi Sad, Serbia

Abstract

Osmotic treatment (OT) of nettle leaves was assessed in various osmotic solutions (sugar beet molasses – SBM and ternary aqueous solution – TAS), at temperatures of 20, 35 and 50 °C, under the atmospheric pressure. The influence of the kind of utilized osmotic solution, process temperature and osmotic time on the antioxidant activity (AOC), expressed with the spectrophotometric assays (ABTS, FRAP and DPPH), as well as two direct current polarographic assays, Hydroxo Perhydroxo Mercury (II) complex assay, based on the decrease of anodic current and assay based on the decrease of a cathodic current of Hg (II) reduction. For determination of the total phenolic content Folin-Ciocalteu assay was used. The Relative Antioxidant Capacity Index (RACI), obtained by setting equal weight for every involved assay was applied in order to get an extensive comparison among analyzed samples and between the used assays. Based on these results, after the OT of nettle leaves in TAS, the AOC decreased, while the OT in SBM increased AOC values. The phenolic antioxidant coefficients (PAC), calculated as the ratio between particular AO capacity and TPC, were used to achieve a more comprehensive comparison between analysed samples, as well as applied assays. The results of RACI evaluation revealed that the most favorable osmotic treatment is the one performed for 5h at 35 °C.

Keywords: antioxidant activity, nettle leaves, osmotic treatment, sugar beet molasses
Published online
2018-11-30
How to Cite
Knežević, V., Pezo, L., Lončar, B., Filipović, V., Nićetin, M., Gorjanović, S. and Šuput, D. “Antioxidant Capacity of Nettle Leaves During Osmotic Treatment”, Periodica Polytechnica Chemical Engineering. doi: https://doi.org/10.3311/PPch.12688.
Section
Articles