Relative evaluation of in-vitro antioxidant potential and phenolic constituents by HPLC-DAD of Brassica vegetables extracted in different solvents

Cabbage, cauliflower and broccoli are well-known vegetables from the Brassica family having functional effects on human health. This study was carried out to identify different antioxidant properties and to quantify phenolic compounds by HPLC-DAD in different extracts (methanol, ethanol and water: acetic acid: acetone) of these vegetables. The results showed that, the methanolic dry extract of cabbage possessed the highest antioxidant activity (549 ± 7.30 μg/g) and IC50 was 90 ± 2.52 μg/mL than others. Whereas the ethanolic dry extract of cauliflower had 348 ± 5.20 μg/g of flavonoid, which was the highest among all. The maximum levels of total tannin (414 ± 5.20 μg/g) and total phenolic content (465 ± 3.25 μg/g) was found in broccoli dry extract. Several polyphenolic compounds were identified in different extracts of the vegetables and they were Cauliflower (8) > Cabbage (10) > Broccoli (9) in total. Therefore, the use of total vegetables rather than extracts in the food industry would be more appropriate to get greater health benefit.