Effect of Ethanol Concentration on the Antioxidant Activity of Red Spinach (Amaranthus tricolor L.) Leaves.

Abstract

Background: Red spinach (Amaranthus tricolor L.) is an important source of anthocyanins and flavonoids with promising antioxidant activity. This activity is influenced by extraction conditions, particularly ethanol concentration. Objective: This study evaluated the effect of 50%, 73%, and 96% ethanol concentrations on the antioxidant activity of red spinach leaf extracts. Methods: Leaves were extracted using Ultrasound Assisted Extraction (UAE), and antioxidant activity was determined using the ABTS assay based on IC50 values. Results: The extract obtained using 73% ethanol exhibited the strongest antioxidant activity (IC50 = 42.8 ± 1.35 ppm), whereas 50% and 96% ethanol produced higher IC50 values. Conclusion: Ethanol concentration significantly affected antioxidant activity, and 73% ethanol was the optimum solvent concentration