Antioxidant properties of Alternanthera sessilis red and green

The study was carried out to investigate the nutritional composition and antioxidant properties of both cultivars. Alternanthera sessilis red (ASR) had significantly higher proximal and mineral contents compared to Alternanthera sessilis green (ASG). Both ASR and ASG had high potassium content (199-1095 mg 100 g^-1 fresh weight). Ethanolic extracts of ASR and ASG had significantly greater antioxidant capacity than their water extracts. Both ethanolic and water extracts of ASR revealed higher antioxidant capacity compared to ASG except for DPPH scavenging ability. The ethanolic extracts of ASR and ASG demonstrated low EC₅₀ values of 180 and 170 ppm, respectively. The ORAC values of ASR and ASG were in the range of 90.67 to 13768.87 µmol of trolox equivalents (TE) 100 g^-1 fresh weight sample. While, FRAP values of studied extracts were in the range of 437.20 to 29255.26 µmol of FeSO₄.7H₂O 100 g^-1 fresh weight sample. The TPC exhibited a positive correlation with all five antioxidant assays. Major phenolic compounds present in ASR were ferulic acid, vanillic acid and epigallocatechin. Whereas, the most abundant phenolic compounds in ASG were vanillic acid, catechin and ferulic acid. Results indicated that phenolic compounds could be one of the main contributors to the antioxidant capacities.