Extraction of antioxidant components from peanut skins

Abstract

The objective of this work was to extract antioxidant components from peanut skins using different solvents and to determine antioxidant activity of the extracts. Methanolic, ethanolic, acetonic and aqueous extracts were prepared from defatted and non defatted peanut skins. Total dry matter content and total phenolic content, radical-scavenging activity and antioxidant activity in sunflower oil were determined from the extracts. The peanut skins used in this work had the following proximate composition: 16.60 % oil, 12.32 % protein, 2.83 % ash and 69.8 % other components. High content of total dry matter was found in methanolic (17.11 %), ethanolic (17.70 %) and acetonic (18.54 %) extracts from non defatted peanut skins. The acetonic extract from defatted peanut skins had lower dry matter extraction than the non defatted peanut skin extract. High content of total phenolics was detected in methanolic (158.6 mg/g) and ethanolic (144.1 mg/g) extracts from deffated peanut skins. These last two extracts in concentration of 1 μg/mL, the radical-scavenging activities were 32.59 % in methanolic extract and 31.5 % in ethanolic extract. All extracts (0.05 % w/w) in sunflower oil showed antioxidant activity. This antioxidant activity from the extracts was lower than that activity from BHT.