What are the three stages of lipid oxidation?
The overall process of lipid peroxidation consists of three steps: initiation, propagation, and termination [31, 36, 37].
What happens to lipids when they are oxidized?
The lipid oxidation process leads to the formation of several components causing off-flavours and reduced nutritional quality. Among these compounds are the free radicals known to be ‘hydrogen thief’s’, steeling hydrogen from other molecules.
Which factors will accelerate lipid oxidation?
The main factors that influence lipid oxidation in meat are fat content and fatty acid composition because fatty acids are the substrate of oxidation processes.
What is lipid oxidation products?
Lipid oxidation is a complex process that produces lipid hydroperoxides (primary products), which can decompose into a variety of oxygenated and aliphatic fatty acid scission products.
How does lipid oxidation occur?
Lipid oxidation can occur by either enzymatic or nonenzymatic catalysis. Nonenzymatic reaction mechanisms can involve catalysis by H2O2, heme iron from myoglobin, nonheme iron, or salts. Antioxidants (e.g., nitrite, ascorbic acid, phenols, or alpha-tocopherol) are effective lipid oxidation inhibitors.
How do you reduce lipid oxidation?
Synthetic antioxidants, such as butylated hydroxytoluene (BHT) and ethoxyquin (EQ), have been used for many years to stop lipid oxidation in foods and feeds (Błaszczyk et al., 2013).
Why is lipid oxidation bad?
ROS oxidize the lipids to generate peroxides and aldehydes. The lipid peroxidation (LPO) products are highly reactive and display marked biological effects, which, depending upon their concentration, cause selective alterations in cell signaling, protein and DNA damage, and cytotoxicity.
What increases fat oxidation?
Ingesting carbohydrate prior to exercise has been found to decrease fat oxidation rates by ~30%. Ingestion of green tea, New Zealand blackcurrants (NZBC), caffeine and omega-3 fatty acids have been suggested to increase fat oxidation.
How does lipid oxidation occur in food?
Lipid oxidation has been long been recognized as a major problem in the storage of fatty acids in foods. Oxidation occurs by several molecular mechanisms such as generation of reactive oxygen precursors and free radicals. Antioxidants and chelating agents are the most helpful inhibitors of lipid oxidation.
What is the function of oxidation?
Oxidation is a major protein degradation pathway which can result in the covalent modification of amino acid residues in the protein chain. Oxidizing agents such as peroxides, dissolved oxygen, metal ions, light and free radicals can catalyze the reaction.
How oxidation in food happens?
When chemicals in food are exposed to oxygen in the air, their chemical composition changes and they begin to break down. Animal and plant tissues contain antioxidant molecules to prevent this from happening. These molecules can slow the rate of oxidation in our foods.
How are conjugated double bonds broken down in lipid oxidation?
Conjugated double bonds (conjugated dienes) absorb ultraviolet light strongly at 233nm. In the later stages of lipid oxidation the conjugated dienes (primary products) are broken down into secondary products (which do not absorb UV-visible light strongly) which leads to a decrease in absorbance.
How to calculate the maximal amount of conjugated diene?
Using experimental curves of oxidation kinetics (Figure 1 ), the lag time, maximal conjugated diene (CD) production (CD max ), rate of diene production (V max ), and time (T max) to reach maximal amount of CD formed were calculated.
Why are conjugated dienes a critical trait of lipoprotein?
Conclusions. Rather than oxidizability of apo B‐containing lipoproteins, the ability of these molecules to produce high levels of conjugated dienes, which can act as toxic tissue messengers, appears to be a critical trait in the development of renal fibrosis in this rat model of obesity and renal fibrosis.
What are the end products of lipid oxidation?
The significant end products of lipid oxidation are rancid-smelling flavor aldehydes derived from the fatty acids (either free or as part of the triglyceride). Each fatty acid can form several flavor volatiles and the large range of fatty acids in a real oil mean a wide range of flavors can be generated.
