Spectrophotometric Evaluation of Antioxidant Content and Capacity of Three Aqueous Extracts of Four Types of Capsicum Annuum (Pepper) Grown in Jordan

Abstract

This research aimed at comparing the antioxidant content and capacity of three different colors (green, yellow and red) of Capsicum annuum variety of sweet pepper and hot green pepper grown locally in Jordan. Additionally, this research aimed at finding the correlation (if any) between the antioxidant content and antioxidant capacity of the studied fruits. Antioxidant content (total phenolic and total flavonoids contents) was analyzed by two spectrophotometric methods; the Folin-Ciocalteu method and the colorimetric aluminum chloride assay method. The antioxidant capacity was determined by two methods: the 2,2-diphenyl-picrylhydrazyl (DPPH) as well as the cupric antioxidant reducing capacity (CUPRAC) assays. Three solvents were used for fruit extraction (methanol, ethanol and water). Yellow pepper contained the highest concentration of total polyphenols and expressed the highest antioxidant capacity analyzed by the DPPH assay. On the other hand, hot green pepper contained the highest amount of total flavonoids.

Different solvents showed significant differences in extracting antioxidants and exerting antioxidant capacities. Water and methanol extracts were more efficient than methanol in extracting polyphenols and flavonoids, respectively. The results were compared with literature values.