Quantification of the Antioxidants and Assessment of the Antioxidant Activity of Two Cucurbita Species Harvested in Bejaia (Algeria)

Abstract

Background: The cucurbit fruits are usually used around the world and are seasonal products traditionally used in human food. They are considered as a source of antioxidants which protect human body from several diseases. Objective: The aim of this study is to evaluate the antioxidant contents (total phenolics, flavanoids, flavanols, condensed tannins, carotenoids, and vitamin C) and the antioxidant activity of the fruits of Cucurbita pepo and Cucurbita moschata harvested in Bejaia from Algeria. Methods: The quantification of the antioxidants was performed using spectrophotometric methods. The antioxidant activity of the extracts was determined using the DPPH• and the ABTS•+ radical scavengers effect. Beforehand, the optimization of the solvent extraction of total phenolics was investigated using 7 different solvents: water, acetone and ethanol at 90, 60 and 30% (v/v). Results: The results showed that the acetone 90% (v/v) was the solvent which gave the extract with the better content of total phenolics (42.44 ± 0.41 mg Gallic Acid Equivalent/100 g FW). The concentrations of total phenolics, flavonoids, flavonols, carotenoids and vitamin C were higher in C. pepo than C. moschata. The higher antioxidant activity of the acetone extract was showed by C. moschata fruit (38.66 ± 1.39%) for DPPH• radical, while C. pepo fruit developed the higher antioxidant activity for ABTS•+ radical (46.89±1.05%). Conclusion: The richness of Cucurbita species in antioxidants allows them to be used in different industries including agri-food to protect from oxidation.