Cooking oil fume is the thermal oxidation decomposition product of cooking oil and food after a series of complex changes under high temperature heating conditions, and some decomposition products are emitted into the air in the form of smoke to form oil fume. When cooking oil is heated to 170℃, it will produce a small amount of smoke. With the continuous increase of temperature, the decomposition speed is accelerated. When the temperature reaches 250℃, a lot of oil smoke is produced.
Cooking oil fume is a group of mixed pollutants, and its composition is very complex. Its composition and toxicity are related to many factors such as the variety of edible oil, processing and refining technology, deterioration degree, heating temperature, material and cleanliness of heating container, fuel used for heating, type and quality of cooking materials and so on. It is reported that gas chromatography and mass spectrometry can detect more than 220 components, mainly including aldehydes, ketones, hydrocarbons, fatty acids, alcohols, aromatic compounds, esters, lactones and heterocyclic compounds. According to research, cooking oil fume also contains dozens of known mutagenic and carcinogenic substances such as B [α] P, volatile nitrosamines, heterocyclic amine compounds, etc. A large number of carcinogenic polycyclic aromatic hydrocarbons (PAHs) have been detected in the oil fume of some catering industries in China. B[α]P in the oil fume of a fried dough sticks shop is 1.483 μ g/g, which is more than 122 times higher than that of unheated oil and 5 1 times higher than that of heated oil.