Toxic aldehydes in cooking vegetable oils: Generation, toxicity and disposal methods

Abstract

The generation of toxic aldehydes in vegetable oils subjected to high-temperature cooking processes, such as frying, poses significant health risks due to their high reactivity and potential to form carcinogenic and mutagenic compounds. This review discusses the mechanisms of aldehydes formation in vegetable oils, focusing on key factors such as oil composition, cooking temperature, and heating time. The major toxic aldehydes identified include acrolein, acetaldehyde, formaldehyde, t,t-2,4-decadienal (t,t-2,4-DDE), 4-hydroxy-2-hexenal (4-HHE), and 4-hydroxynonenal (4-HNE), which have been associated with adverse health effects ranging from respiratory irritation to carcinogenicity. Currently employed air purification methods aimed at mitigating exposure to these toxic compounds in domestic and industrial settings are analyzed. Strategies such as ventilation improvements, activated carbon filters, and emerging technologies like catalytic combustion are evaluated for their effectiveness in reducing aldehyde concentrations. Further research is needed to optimize air purification techniques to reduce air pollution and protect public health from harmful aldehyde exposure.

Fig. 1

The trend of consumption of representative VOs per year in the world. Other oils: palm kernel oil, peanut oil, cottonseed oil, coconut oil, and olive oil.

Fig. 2

Chemical classes of compounds present in VOs (green panel) and hazardous by-products generated during high-temperature heating (orange panel). (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

Fig. 3

Generation of toxic aldehydes from linoleic acid via peroxidation mechanisms: autoxidation (purple panel) and photosensitized oxidation (green panel); 4-HHE: 4-hydroxy-2-hexenal; 4-HNE: 4-hydroxynonenal; t,t-2,4-DDE: t,t-2,4-decadienal. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

Fig. 4

Cellular toxicity induced by electrophilic aldehydes generated from VOs degradation processes. Toxic aldehydes produced by fatty acid peroxidation induce several cellular damages such as conformational changes in enzymes and ion channels, protein adducts formation, ROS production, and activation of pro-inflammatory pathways which increase oxidative stress, DNA fragmentation, and necrosis.