In vitro antioxidant and metal chelating properties of corm, tepal and leaf from saffron (Crocus sativus L.)

• Published in: Industrial crops and products 2012-09, Vol.39, p.149-153
• Main Authors: Sánchez-Vioque, R., Rodríguez-Conde, M.F., Reina-Ureña, J.V., Escolano-Tercero, M.A., Herraiz-Peñalver, D., Santana-Méridas, O.
• Format: Article
• Language: English
• Subjects: antioxidant activity; Bioactive compounds; By-products; byproducts; chelates; chelation; corms; Crocus; Crocus sativus; free radical scavengers; Free radicals; iron; leaf extracts; leaves; Metal chelating; nitric oxide; oxidation; Reactive oxygen species (ROS); saffron; stigma
• ISSN: 0926-6690; 1872-633X
• DOI: 10.1016/j.indcrop.2012.02.028

► Antioxidant properties of saffron by-products tested by in vitro methods. ► Leaf extract totally inhibited β-carotene oxidation at 10μg/mL. ► Very high DPPH scavenger activity of leaf extract ► Tepal extract inhibits β-carotene oxidation, scavenger NO and chelates Cu2+ efficiently. ► Poor antioxidant properties of corm extract. ► Tepals and leaves are an exploitable source of antioxidant compounds. Corms, tepals and leaves of saffron are by-products generated during the processing of the stigmas of the flower (saffron spice). To increase the overall profitability of this crop, these by-products have been investigated as a potential source of antioxidant compounds. With this purpose, several in vitro antioxidant methods, such as the β-carotene/linoleate model system, reducing power, DPPH and nitric oxide radical scavenging, and iron and copper ion chelation have been assayed on corm, tepal and leaf extracts. Best antioxidant properties were observed for leaf extract, which totally inhibited the oxidation of β-carotene at 10μg/mL and showed a DPPH scavenger activity up to 32 times higher than those reported for traditional sources of antioxidants like grapes and berries. Tepal extract showed an extensive inhibition of β-carotene oxidation, and significant scavenging NO radical and Cu2+-chelating activities. In contrast, corm extract was a poor antioxidant although showed a slight Cu2+-chelating activity. It can be concluded that tepals and especially leaves of saffron constitute an exploitable source of antioxidant and metal chelating compounds.