Effect of Extraction Solvents on Phytochemicals and Antioxidant Potential of Turnip Roots (Brassica rapa L.)

Abstract

Background: Brassica rapa (L.) is commonly used as vegetable because of its antioxidant and medicinal properties. Thus, turnip (variety White 4) was characterized by its chemical composition and mineral profile procured from CCS Haryana Agricultural University in Hisar. The effect of solvent on extraction of phytochemicals was investigated. Methods: Antioxidant potential including total phenolics content (TPC), total flavonoids (TFC), the free radical scavenging activity (DPPH assay) and total antioxidant capacity (TAC) was analyzed. Result: The aqueous extract contained the highest total phenols (4.56±0.02 mg GAE/g) and flavonoids (2.07±0.05 mg CE/g) as compare to ethanol and acetone extracts. The DPPH free radical scavenging activity of turnip root extracts was highly variable and increased with increasing concentration levels. The aqueous extract showed the best DPPH free radical scavenging activity at the IC50 value (1.26 mg/mL) followed by ethanol (11.30 mg/mL) and acetone (12.08 mg/mL) extracts. The total antioxidant capacity was highest in aqueous extract (3.45±0.03) as compared to ethanol (2.95±0.07) and acetone (0.81±0.08 mg AAE/g).