Résumé:
The aim of this work was to determine the total polyphenols and flavonoids of four plants: lemon, orange, verbena, and mint, and to evaluate their antioxidant activity. The content of polyphenols and total flavonoids was determined by colorimetric methods. The obtained results showed that clementine peels contain a good content of total polyphenols, followed by mint leaves, lemon peels, and lastly verbena leaves with respective values of 3.38±0.07 mg GAE/g FM, 2.22±0.08 mg GAE/g FM, 2.13±0.01 mg GAE/g FM, and 0.43±0.03 mg GAE/g FM. For total flavonoids, clementine peels gave a good value followed by lemon peels, mint leaves, and verbena leaves with contents in the range of 1.89±0.03 mg QE/g FM, 1.1±0.09 mg QE/g FM, 0.91±0.06 mg QE/g FM and 0.30±0.011 mg QE/g FM, respectively. The antioxidant activity was evaluated by DPPH test, according to the results, clementine peel polyphenols show a good antioxidant effect with IC50 values of 0.125 mg/mL followed by mint phenolic extract (0.399 mg/mL), lemon peel (2.943 mg/mL), and finally verbena leaves (5.835 mg/mL).
