Recent epidemiological studies have shown positive effects of coffee-drinking on many chronic diseases induced by ROS. Coffee antioxidant properties can be considered responsible for such effects. The roasted coffee antioxidant properties are prevalently studied in chemical systems and attributed to natural coffee polyphenols as well as to Maillard reaction melanoidins. In this paper the antiperoxyl radical activity of roasted coffee was evaluated in an ex vivo system consisting of rat liver cell microsomes in which lipid peroxidation is induced by xenobiotic. The anti-peroxyl radical activity was evaluated as protective activity (PA) against lipid peroxidation and measured as TBA-reacting substances. Coffee brew resulted to be able to completely inhibit lipid peroxidation. The main responsible for this action are the high molecular mass (MM>3500 Da) components that fractionated by gel filtration chromatography, permitted the recovery of 3 melanoidin components possessing PA. The UV spectrum of the most active melanoidin presents two absorption maxima at 302 and 324 nm, indicating the presence of hydroxycinnamic derivatives confirmed by the change in the UV spectra depending on acid or alkali medium. The release of bound phenolic compounds from this melanoidin was obtained by salt treatment and RP-HPLC-DAD analysis enable to identify and quantify 5-O-caffeoyl-quinic acid.
Ex vivo antiperoxyl radical activity of coffee melanoidins
DAGLIA, MARIA;PAPETTI, ADELE;ACETI, CAMILLA;SPINI, VALENTINA;SORDELLI, BARBARA;GREGOTTI, CESARINA;GAZZANI, GABRIELLA
2007-01-01
Abstract
Recent epidemiological studies have shown positive effects of coffee-drinking on many chronic diseases induced by ROS. Coffee antioxidant properties can be considered responsible for such effects. The roasted coffee antioxidant properties are prevalently studied in chemical systems and attributed to natural coffee polyphenols as well as to Maillard reaction melanoidins. In this paper the antiperoxyl radical activity of roasted coffee was evaluated in an ex vivo system consisting of rat liver cell microsomes in which lipid peroxidation is induced by xenobiotic. The anti-peroxyl radical activity was evaluated as protective activity (PA) against lipid peroxidation and measured as TBA-reacting substances. Coffee brew resulted to be able to completely inhibit lipid peroxidation. The main responsible for this action are the high molecular mass (MM>3500 Da) components that fractionated by gel filtration chromatography, permitted the recovery of 3 melanoidin components possessing PA. The UV spectrum of the most active melanoidin presents two absorption maxima at 302 and 324 nm, indicating the presence of hydroxycinnamic derivatives confirmed by the change in the UV spectra depending on acid or alkali medium. The release of bound phenolic compounds from this melanoidin was obtained by salt treatment and RP-HPLC-DAD analysis enable to identify and quantify 5-O-caffeoyl-quinic acid.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
