Comparison of Measurements of Antioxidant Activity in the Selected Leafy Vegetables Depending on Extraction Solvent

Abstract

Four leafy vegetable species, spinach (Spinacia oleracea), amaranthus (Amaranthus viridis), fenu-greek (Trigonella foenum-graecum) and bathua (Chenopodium album), were extracted with three different solvents (80% ethanol, 80% acetone and water) for maximum recovery of phenol and antioxidant compounds in the extract. The results of extraction were compared with extraction from moringa (Moringa oleifera) leaves that is known as a very rich source of antioxidants. The study showed that, it is very difficult to justify a single solvent for extraction of antioxidant compounds from different plants. Results from different solvents used for extracting the bioactive compounds mostly depend on the type of compound extracted (polar/medium polar/non-polar) present in leafy matrices. Here, 80% acetone extract showed highest total phenol content in moringa leaves but the overall antioxidant activity in the leaves of four vegetables was observed to be better after extraction with 80% ethanol. Nevertheless, in most assays, independent of solvent used for extraction, the moringa leaves were the richest source of polyphenols and antioxidants.

Keywords

• antioxidant activity
• effect of extraction
• leafy vegetables
• polyphenols
• solvent extraction