PHYTOCHEMICAL STUDY OF THE THREE MAIN ONION VARIETIES (ALLIUM CEPA L.) GROWN IN ALGERIA

Abstract

Three species of Allium cepa (red, purple, yellow) were evaluated for their secondary metabolite content, free radical scavenging activity (DPPH), and ferric reducing ability (FRAP). Our findings confirm that the dry matter content in all varieties ranged from 12.3% to 18.1%, rendering them suitable for extended storage. The ethanolic extract of red onion (EERO) displayed the highest yield (3.86%). Similarly, the levels of total phenols (TPC), total flavonoid content (TFC), hydroxycinnamic acid (HTC), and cysteine-containing peptide (CTC) varied between 0.14 and 0.27 mg/g GAE, 0.20 and 0.29 mg/g QE, 0.25 and 0.29 mg/g GAE, and 0.015 and 0.102 mg CE/g DW, respectively. Furthermore, ethanolic extract of yellow onion (EEYO) demonstrated a significant iron reduction capacity (0.75 ± 0.06 mM Fe2+) and an IC50 of 0.159 ± 0.18 mg/ml, indicating enhanced antioxidant potential.