Study on the antioxidant potential of Catharanthus species and its thermal stability in sunflower oil model system

Abstract

The studies analyze the efficiency of Catharanthus alba and Catharanthus roseus cultivars as a natural antioxidant measuring antioxidant potential through two methods. In the first method, antioxidant activity was estimated through the sunflower oil model system in which the Peroxide value (PV) and Thiobarbituric acid (TBA) tests were performed. While in the second method, antioxidant activity estimation is done through the assay method in which 2, 2- Diphenyl- 1-picrylhydrazyl (DPPH) radical scavenging method and ammonium thiocyanate method has been performed. The thermal stability of the leaves & flowers of Catharanthus alba and Catharanthus roseus were analyzed by mixing of powdered medicinal plant and sunflower oil. Further results indicate the higher antioxidant activity of flower Catharanthus alba as compared to flower Catharanthus roseus. Relatively among the leaves, Catharanthus roseus demonstrated slightly higher antioxidant potential than the leaves of Catharanthus alba. The antioxidant activity of Catharanthus alba (Flower)> Catharanthus roseus (Flower)> Catharanthus roseus (leaves)> Catharanthus alba (leaves) has been reported. The dehydrated powders of leaves and flowers of Catharanthus alba and Catharanthus roseus have shown good antioxidant activity at 0.5% level in sunflower oil while increase in concentration up to 1% and 1.5% does not show enhanced antioxidant activity in sunflower oil. The flowers and leaves of both cultivars of Catharanthus have shown good thermal stability when heated at 80 oC continuously for 24 h considering all the parameters with statistical significance of (p LESS-THAN OR EQUAL TO 0.001).