Mechanism Of Volatile Compound Formation From Soybean Oils In A Semi-continuous Heating Process

Oils is one of the important sources of energy intake in people's daily life.It is not only the basic nutrient component of food,but also the main source of food flavor.In this paper,the commonly used edible vegetable oil—soybean oil was investigated that the composition and formation mechanism of volatile compounds in soybean oil during the semi-continuous heating process.And the specific research detail are:1.A new extraction method was developed that vacuum-assisted headspace solid-phase microextraction-gas chromatography-mass spectrometry in this paper,and its related parameters were optimized.Application of optimized conditions to detect that the composition of volatile compounds from soybean oil in semi-continuous heating process.A total of 112 volatile flavor substances were detected and analyzed,composing aldehydes(27),alcohols(14),ketones(10),furans(6),aromatic compounds(9),acids and esters(6),alkanes(34)and others(6).Simultaneously,the principal component and the heat map were used to analyze the characteristics of the volatile components of soybean oil at each temperatures.The temperature points and temperature range for different volatile compounds were determined,especially the appearance temperature for most aldehydes,above 120 °C.2.This paper investigated the effect of oxygen on the formation of volatile compounds in soybean oil during heating process,and primary studies the production of volatile compounds in soybean oil under aerobic and anaerobic conditions at higher temperature.Studies have shown that the type and relative content of the volatile compounds of soybean oil during heating process produced under anaerobic conditions were smaller than under aerobic conditions.Especially for furans compounds,and only a volatile compound that 2-pentylfuran was detected.3.In order to further reveal the formation mechanism of the flavor from soybean oil,this paper studied the formation of volatile compounds during the semi-continuous heating process from the relative higher contents of fatty acid that oleic acid(C18:1n-9)in soybean oil.And determined the types and relative content of the volatile compounds produced by the oxidation and decomposition of C18:1n-9 at each temperatures,basically make clear the formation mechanism of the volatile substances in soybean oil.4.The composition of volatile compounds from soybean oils with added natural antioxidant vitamin E and synthetic antioxidant butylated hydroxytoluene during the semi-continuous heating process were study in paper.The results showed that the addition of antioxidants to soybean oil can significantly reduce the types and relative content of volatile compounds.In other words,antioxidants can stop effectively the oxidation of oils.Whereas the thermal stability of these two kinds of antioxidants is relatively not stable,and they were decomposed when the temperature is higher than 120 °C,which provides a reference for artificially adjust and control the flavor of oil heating processing.