Interaction of fatty acids, prooxidants, antioxidants in the oxidation of cholesterol in model system

• Grant number: 10/12169-1
• Support type: Scholarships in Brazil - Doctorate
• Effective date (Start): October 01, 2010
• Effective date (End): February 28, 2014
• Field of knowledge: Agronomical Sciences - Food Science and Technology - Food Science
• Principal Investigator: Neura Bragagnolo
• Grantee: Elisângela Serenato Madalozzo
• Home Institution: Faculdade de Engenharia de Alimentos (FEA). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

Cholesterol is one of the most important sterol present in animal tissues, it can be present in free form or as cholesterol esters, combined with long-chain fatty acids is a essential structural component of membranes and lipoproteins. There is a double bond in the chemical structure of cholesterol, making it therefore susceptible to oxidative reactions, which may lead to the formation of many cholesterol oxides products (COP's). Even if protected from oxidation, can be degraded by auto-oxidation and when the cholesterol is exposed to presence of metals such as iron, zinc and copper the oxidation is accelerated. The use of antioxidants can retard or prevent the formation of COP's, in this way interrupt the mechanism of formation of free radicals by donating protons, both for the unsaturated fatty acids as for cholesterol. The objective of this project is to verify the impact of using different antioxidants (bixin, sodium erythorbate and rosemary essential oil) on the thermal degradation of cholesterol in model systems in the presence and absence of transition metal chloride (Fe+2, Fe+3 and Fe heme), oxygen and fatty acids with different degrees of unsaturation (oleic acid, eicosapentaenoic acid and palmitic acid). The action of antioxidants and pro-oxidants will be monitored by the formation of COP's and alteration in fatty acid composition and degradation of antioxidants added to model systems subjected to temperatures of 70, 90 and 110°C.