Investigate The Content Of Trans Fatty Acid In Food By Gas Chromatography

Trans fatty acid is the generic name of a group of unsaturated fatty acid which includes trans conjugated double-bonded. A high intake of trans fatty acid may threaten human health seriously. Trans fatty acid have some side effects on human, it can induce cardiovascular disease, the decline of cognitive function, the digestion and absorption of essential fatty acid, and so on. Along with the continuously go deep into of the research, control of trans fatty acid intake gradually become the focus of attention. Than methods for detecting content of trans fatty acid for all kinds of food became a hot topic in the food safety areas. The harm of trans fatty acids and the technological study situation at home and abroad are summarized in this paper. After discussing the optimization condition of pretreatment and gas chromatography conditions, a gas chromatographic protocol for analysis of trans fatty acid was established, and then applied to survey TFA distribution in commonly oil-involved foods. Its main contents are as follows:1. Optimization of pretreatment method of the sample:The main influence factors of fatty acid methyl are esterifying agent concentration, esterifying agent dosage, esterification reaction temperature, esterification reaction time, standing time of the sample. Selecting corn oil as experimental material and peak area response value and esterification rate of thirteen silane acid methyl ester as primary target, the article mainly castigated the method of the pretreatment conditions of BF3-CH3OH by orthogonal testing method. The optimum pretreatment conditions were settled as 8mL 20% BF3-CH3OH as derivative reagent, hermetically heating 10min at 80℃and sample could be tested as soon as possible.2. Optimization of conditions of operation in gas chromatography:This study separates fatty acid methyl ester standard samples with gas chromatography in order to optimize separation conditions of gas chromatography. The results are as follows: Injection port temperature:260℃; Detector:FID,280℃; Input mode:Splitless injection; Injection volume:1μL; Carrier gas:Nitorgen; CC mode flow rate:2mL/min; Gasratio:nitrogen:hydrogen:air=45:30:300: Oven temperature:140℃(hold 2min) to 200℃(hold 10min) at 10℃/min 200℃(hold 10min) to 260℃(hold 10min) at 3℃/min 260℃(hold 10min) to 280℃(hold 2min) at 20℃/min;3. Investigate the content of trans fatty acid in food by using gas chromatography:A gas chromatographic protocol for analysis of trans fatty acid was established, and then applied to survey TFA distribution in 33 oil-involved foods in the daily lives of most resident of China. And the protocol established was shown to have good specificity and high sensitivity. The test results showed that trans fatty acid content is high in cake and biscuit which contains substituted coco fat. While the trans fatty acid intake of Chinese is estimated to provide reliable references of the relevant regulations and resident meals guide formulated by government and the improvement of fermenting process technology to food producers.