Opuntiaficus Indica flower: A prominent source of phenolic compounds and unsaturated fatty acid

Comparison of the total phenol content and the antioxidant activities of three cultivars of Opuntiaficus-indica (L.) Mill. have been evaluated. The results showed that total phenolic compounds were abundant in flowers of all cultivars, the most abundant was found in Gialla cultivar (6.96 mg EGA/g DM). Quite the opposite, the antioxidant activity of the flower extracts was stronger in the Bianca cultivar than the other cultivars. Accordingly, Gialla flower extract exhibited the highest flavonoid content (4.29 mg CE/g DW) followed by Bianca (2.48 mg CE/g DW) and Rossa (1.64 mg CE/g DW). Likewise, Gialla flower extract exhibited the highest anthocyan content (0.30 mg / 100g FW) followed by Rossa (0.24 mg / 100g FW) and Bianca (0.16 mg / 100g FW). The same tendency was observed for the amount of tannins. The Rossa flower extracts displayed the highest DPPH scavenging (55.17%) followed by Gialla cultivar (54.73%) and Bianca cultivar (52.80%). Furthermore, flower extracts showed appreciable antibacterial properties against human pathogen strains. The mean inhibition zone was from 8.33 to 11 mm when the concentration was 50 mg/l. The strongest activity was recorded against Enterococcus facium and the lowest activity was observed against Candida albicans. Whereas, flower extracts were efficient to inhibit growth of pathogenic bacteria mainly against Staphylococcus aureus and Echerchia coli. The data indicate that Opuntiaficus-indica flower is a rich source of natural antioxidants for foods. Subsequently compositions and concentrations of fatty acids, total lipids recovered were found to be 4.84 % (on dry weight). Among the total lipids, linolenic and palmitoleic acid were the dominating fatty acid and were estimated to be in relatively equal amounts 26.37 and 27.05 % respectively followed by linoleic and oleic acid. These findings suggest that Opuntiaficusindica flower may be considered as an interesting source of antioxidants for therapeutic or nutraceutical industries and for food manufactures.