Effects of different harvesting seasons on antioxidant activity and phenolic content of prickly pear cladode juice

The study was carried out to evaluate the effect of environmental conditions on the phenolic content and antioxidant activity of two distinct cladode genotypes under three sampling dates (spring, summer, and winter). The juice extracted from Opuntia ficus-indica (spineless) and Opuntia megacantha (spiny) genotypes was analyzed for their phenolics content and antioxidant activity using DPPH, ABTS, and FRAP methods. The composition of major phenolics substances of cladode juice harvested in March was determined by HPLC analysis. The average of the total phenolics content ranged from 455.65 to 542.70 μg GAE mL−1. The antioxidant activity varied from 1.78 to 4.10 μmol TE mL−1 by DPPH assay, 12.78–23.10 μmol TE mL−1 by ABTS assay and 1.74–3.33 μmol TE mL−1 by FRAP assay. Higher values of antioxidant activity and polyphenols content were registered in summer. O. ficus-indica recorded significantly higher values for the parameters compared to O. megacantha. Keywords: Prickly pear cactus, Opuntia ficus-indica, Opuntia megacantha, Cladode juice, Antioxidant activity, Polyphenol