Productos de oxidación de esteroles en suero y alimentos enriquecidosdeterminación, formación e implicaciones es procesos oxidativos

  1. Menéndez Carreño, María
Supervised by:
  1. Iciar Astiasarán Anchía Director
  2. Diana Ansorena Artieda Co-director

Defence university: Universidad de Navarra

Fecha de defensa: 18 September 2009

Committee:
  1. José Alfredo Martínez Hernández Chair
  2. Adela López de Cerain Salsamendi Secretary
  3. Hans-Gerd Janssen Committee member
  4. Anna-Maija Lampi Committee member
  5. Ana María Troncoso González Committee member

Type: Thesis

Teseo: 107399 DIALNET

Abstract

Cholesterol oxidation products (COPs), which can be absorbed from the diet, have been well documented to exert adverse biological effects. Phytosterols can be also oxidized, giving rise to phytosterol oxidation products (POPs) with several cytotoxic effects, although probably less severe than those promoted by COPs. At first, the aim of this study was to develop and validate a method to detect, identify and quantify the presence of sterol oxidation products (SOPs) in different matrices by using a suitable GC-MS method. COPs were used as model substances assuming a similar behaviour to POPs. COPs have been associated with the development of atherosclerosis and cardiovascular disease (CVD). In this study, it was demonstrated that the formation of serum COPs is partially inhibited by the dietary antioxidants (vitamin C and selenium) intake in rats fed on high fat diets. It has been also found that COPs can be considered as efficient biomarkers to follow-up the development of CVD. Recently, several phytosterol-enriched foods have appeared on the market as they have beneficial effects decreasing LDL serum levels. One of the objectives of this work was to determine how culinary heating treatments affected on these products. It can be concluded that drastic heating conditions affect the stability of sterols although the formation of SOPs commonly measured do not quantitatively account for all sterols losses observed during heating. Polar oxidation products, traditionally identified from sterols oxidations, are not the only degradation products formed by thermo-oxidation as non-polar and mid-polar oxidation monomeric products are also formed.