Investigation of the antioxidant activity and quantification of the amount of heavy metals and some vitamins in carrot

Abstract

Background: Carrot is a root vegetable from the Umbelliferae family. It is a biennial plant grown for their edible root. Carrots are a good source of carbohydrates and minerals like Calcium, Phosphorus, Iron and Magnesium and may contain toxic amounts of metals as a result of run off effects. It is also rich in carotene, niacin, riboflavin, thiamine and vitamin C.
Objectives: To determine the amounts of toxic heavy metals, quantify the amounts of vitamins A and E and investigate the antioxidant activities of Carrot.
Method: The research investigated the antioxidant properties of carrot on the basis of the radical scavenging activity on DPPH (1,1-diphenyl-2-picryl hydrazyl), heavy metal analysis were carried out using Flame Atomic Absorption Spectrophotometer while analysis of vitamins was done using HPLC (High Performance Liquid Chromatography).
Result: The carrot sample analyzed contained considerable amount of some toxic metals of interest (Cr 0.024, 0.105ppm; Cu 15.76, 30.95ppm; Fe 66.94, 103.95ppm; Zn 16.57, 44.22ppm; Pb 0.018, 0.021ppm) in the leaves and root respectively. The samples also contain a very good amount of the vitamin A (12.863, 44.977ppm) and Vitamin E (0.087, 0.22ppm) in leaves and root respectively. It also showed some antioxidant activity and test positive for most phytochemicals.
Conclusion: The actual concentrations of the respective heavy metals found in two parts of the D. carota samples were within the threshold limit but there was slight variation in the amount present in the root D. carota as compared to its leaf. The root had more concentrations of the metals and this could be due to the fact that the root is more exposed to these metals during plant uptake.

Keywords: Heavy metals, Vitamin, DPPH, Antioxidant, Daucus carota