Antioxidant properties and stability of Raphanus sativus extracts

Abstract

The present investigation was planned to analyze the antioxidant components, activity and stability of Raphanus sativus leaves. The antioxidant activity of methanol (ME), ethanol (EE) and water (WE) extracts was determined by DPPH radical scavenging, reducing power and in vitro inhibition of lipid oxidation. Temperature and pH stability of extracts was also studied. The extracts showed a dose dependent scavenging of the free radical; DPPH. EE showed higher activity than ME and WE. The extracts also showed varying degree of reducing capacity. Further, all the extracts inhibited the formation of lipid peroxides and their efficacy was in the order of a-tocopherol (80%)>EE (69%)>WE (70%)>ME (65%). The activity of WE was increased by 3% after heat treatment. The antioxidant activity of EE at both pH 4 and 7 was higher than WE and ME. At pH 7 all the extracts were stable and at pH 9 no activity was shown. Data indicates the potentiality of the Raphanus sativus leaves to utilize as a natural antioxidant.