Lipid oxidation Flashcards
What are short chain triglycerides prone to?
Hydrolytic rancidity
What are unsaturated chains prone to?
Autoxidation, photo-oxygenation and lipoxygenase
Primary reaction product of lipid oxidation
Hydroperoxides
Secondary reaction products cause what?
Oxidative rancidity and polymerisation of oil
Properties of configurational isomers of unsaturated fatty acids
Molecules can’t rotate around double bonds
Unsaturated fatty acyl groups have one or more carbon double bond
Mostly found in cis formation
Cis vs trans fatty acids
Cis=all carbons above double bond
Trans=carbons below double bond
Where does autoxidation occur?
Ground state oxygen and molecules containing carbon double bonds
What are free radicals?
Molecules containing one or more unpaired electrons
What is photo-oxygenation?
Formation of hydroperoxides in the presence of visible light and chemicals
Differences between photooxygenation and autoxidation
Photooxygenation isn’t free radically driven and is much faster
How does the OOH group effect lipids?
Can increase viscosity and produce flavours and oxidising agents
How to reduce lipid oxidation
Reduce light, O2, UFAs and temperature
Good quality oil
Control water activity
What are antioxidants?
Substances which prevent the oxidation of materials
What are E300’s?
Acidity regulators and antioxidants
What are the functions of E300’s?
Chain blocking
Inhibit peroxide decomposition
Regenerate antioxidants
