The cause of the presence of toxic substances in food is sometimes due to the fact that these have been subject to processes of degradation. The oxidation or thermal degradation of food lipids causes deterioration in foodstuffs and the generation of toxic substances.
At the EHU-UPV (University of the Basque Country) Pharmacy Faculty they have been studying the process of the oxidative degradation of foodstuffs. Research began with oils, given that these are exclusively (99 %) made up of lipids while, in subsequent stages, the study was extended to other foods prone to undergoing processes of oxidative degradation.
Researchers investigated processes of oxidative degradation - notably that caused at 70ºC with ventilation - of a broad group of oils with very wide-ranging compositions. Another degradation process studied was that which is caused by microwave action that does not heat greater than a temperature of 190 ºC.
These studies have shown, for the first time, that degradation of lipids in foods can produce toxic oxygenated aldehydes. These compounds, well-known in medical studies for their geno- and cytotoxic activity, considered as markers of oxidative stress in cells as well as being causal agents of degenerative illnesses, had not previously been detected in foodstuffs.
Researchers have shown that some oils produce these toxic substances in greater quantities and at a greater rate. Virgin olive oil was, amongst all the oils studied, that which took longer to produce this type of compounds and produced a lower concentration of them.
The presence of toxic oxygenated aldehydes in fats and oils subjected to thermal treatment highlights the need to control the manufacture and preparation processes of foodstuffs as well as the fatty material employed, given their capacity to generate these oxygenated aldehydes responsible for degenerative illnesses.
MEDICA.de; Source: Basque Research