Soxhlet extraction and characterisation of natural compounds from walnut (Juglans regia L.) by-products

Abstract

Walnut leaves, green husk and membrane septum (woody septum) are agro-forest wastes generated in the walnut (Juglans regia L.) harvest that could be valued as a source of natural compounds with antioxidant properties. The extractive efficiency of bioactive compounds (phenols) from plant material is greatly depended on the extraction technique. In this study, was proposed to extract phenol compounds by Soxhlet extraction with water/ethanol mixtures as a solvent. The free radical scavenging activity of studied extracts was evaluated by employing antioxidant assay system. The total phenols content of the extracts was determined using the Folin-Ciocalteu method to assess their contribution to the antioxidant activity. Extract radical scavenging activity as well as the kinetics of inhibition of free radicals were evaluated in terms of radical scavenging ability using the stable 2,2 diphenyl-1-picrylhydrazyl radical (DPPH•).UV spectra of the investigated extracts were also analyzed.