Antioxidant and Pro-oxidant Behaviour of Polyphenolic Compounds in Model systems and foods

NAZARENO M. A.

Córdoba

Workshop; Fisicoquímica: Proyecciones de una disciplina en movimiento? Reunión Científica con motivo del 30° Aniversario del INFIQC; 2013

INFIQC. Universidad Nacional de Córdoba

Polyphenols are compounds widely distributed in the plant kingdom. They are produced by higher plants as secondary metabolites with very specific functions. Their chemical structures and molecular sizes are quite varied as well as their bioactivities. These natural compounds present different antioxidant mechanisms in order to protect cells and other biological systems from oxidative damages. It has been extensively demonstrated their actions as free radical scavengers, chelators of metal ions as well as inhibitors of pro-oxidant enzymes. However, there is growing scientific evidence that in the presence of certain metal ions or in high doses their behavior turns to prooxidant. In our working group, we are conducting comprehensive study of their chemical reactivity. Besides, mechanistic aspects as well as their potential applications for the development of new bioactive materials with properties of industrial interest are also subject of our research. We studied the interaction of polyphenols with other antioxidants to evaluate possible synergistic effects. Polyphenol immobilization was investigated in polymeric matrix by covalent linkage to film surfaces or macroporous solids or by secondary interactions as adsorption mediated by the hydrogen-bond formation to polar solids. The synthesis of antioxidant polymeric materials by immobilization of polyphenols has been carried out to develop "active" packaging and radical scavenger filters. We evaluated the inhibitory capacities of a series of polyphenols against oxidative enzymes in model systems. The effect of polyphenols against thermally induced oxidation was studied in model systems containing unsaturated lipids both as a food matrix and micro-heterogeneous solutions.