Table 1.

Schedule of evaluation of oxidation or chelation of Fe²⁺/Fe³⁺ by plant extracts.

Time	Sequence of Addition	Reading at 510 nm
0 min	Extract (30–120 μg/mL)	-
	FeSO4 (110 μM)
10 min	Ortho-phenanthroline (0.25%)	-
10 min	Immediately after mixing with	First reading (0 min)
	Ortho-phenanthroline
20 min	-	Second reading (10 min)
30 min	-	Third reading (20 min)
30 min	Ascorbic acid (AA, final concentration, 5 mM)	-
35 min	-	First reading after AA (25 min)
40 min	-	Second reading after AA (30 min)
50 min	-	Third reading after AA (40 min)