Vitamin C content and antioxidant activity of eight selected vegetables widely consumed in Addis Ababa, Ethiopia

Abstract

The objectives of the study were to determine vitamin C content using iodometric titration and its antioxidant activity as a DPPH assay by UV−Vis spectrophotometric method in eight shade-dried vegetables purchased from Addis Ababa in open markets. The linear range of standard vitamin C was in the range 3.2–52 mg/L with a correlation coefficient of R² = 0.994. The vitamin C content was found in the increasing order in eggplant 6.83 mg/100 g < carrot 11.05 mg/100 g < beetroot 15.32 mg/100 g < Swisschard 16.22 mg/100 g < cauliflower 17 mg/100 g < lettuce 21 mg/100 g < cabbage 32.49 mg/100 g < green chili 49.18 mg/100 g. The percentage recoveries of vitamin C in the vegetables ranged from 95.61 to 102.4%, indicating its good reliability. The antioxidant activity of eight vegetables was increasing, namely in eggplant 12.48 mg/100 g < carrot 30.55 mg/100 g < beetroot 30.55 mg/100 g < cauliflower 42.98 mg/100 g < Swisschard 44.57 mg/100 g < lettuce 63.48 mg/100 g < cabbage 100.9 mg/100 g < green chili 106.8 mg/100 g. The results also revealed a strong correlation (R² = 0.9508) between vitamin C contents in the vegetables and their antioxidant activities.

Bull. Chem. Soc. Ethiop. 2025, 39(4), 629-641.                                                           

DOI: https://dx.doi.org/10.4314/bcse.v39i4.3