The effect of gallic acid, catechin and quercetin on physical and chemical stability of olive oil-in-wateremulsions was investigated. These molecules, characterised by different polarity and antioxidant activity,showed different interface activity and efficiency in delaying lipid oxidation. Gallic acid contributed positivelyto stabilise the colloidal properties of the systems toward physical instability whilst showed a lowactivity towards secondary oxidation. Catechin showed an interfacial localisation which was reflected inthe enhancement of primary oxidation and in the inhibition of secondary oxidation. Quercetin poorlypartitioned in the aqueous phase and was proven not to slow down the bimolecular phase of auto-oxidation.Results confirmed that polarity is not the only parameter to determine efficiency of antioxidants inemulsions but other variables, such as its antioxidant activity in terms of capacity and rapidity in donatingan hydrogen atom, can affect its protective role towards lipids auto-oxidation in emulsions.[...]
Effect of phenolic antioxidant on the dispersion state and chemical stability of olive oil O/W emulsions
DI MATTIA, CARLA DANIELA;SACCHETTI, Giampiero;MASTROCOLA, Dino;PITTIA, Paola
2009-01-01
Abstract
The effect of gallic acid, catechin and quercetin on physical and chemical stability of olive oil-in-wateremulsions was investigated. These molecules, characterised by different polarity and antioxidant activity,showed different interface activity and efficiency in delaying lipid oxidation. Gallic acid contributed positivelyto stabilise the colloidal properties of the systems toward physical instability whilst showed a lowactivity towards secondary oxidation. Catechin showed an interfacial localisation which was reflected inthe enhancement of primary oxidation and in the inhibition of secondary oxidation. Quercetin poorlypartitioned in the aqueous phase and was proven not to slow down the bimolecular phase of auto-oxidation.Results confirmed that polarity is not the only parameter to determine efficiency of antioxidants inemulsions but other variables, such as its antioxidant activity in terms of capacity and rapidity in donatingan hydrogen atom, can affect its protective role towards lipids auto-oxidation in emulsions.[...]I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
