Research With The Establishment Of Multi-Component Analysis Method Of Trans Fatty Acids In Food

Trans fatty acids (TFA) are a generic name of a type of unsaturated fatty acids that contain at least one double bond in the trans configuration. TFAs mainly comes from ruminant animal muscle fat and milk fat, grease hydrogenation processing, high-temperature heat treatment plant oil. Studies show that large intake of TFA will harm to human body, such as Trans fatty acids may lead to cardiovascular disease, diabetes and other diseases. Strict actions have been taken in many countries to control the contents of TFAs in food, in order to support the food quality and ensure the life safety of consumer. Such, it has grate theoretical and practical value for the study on determination of trans fatty acids in foods.In this paper, a new analytical procedure has been developed for determination of TFAs through pre-processing and separation with gas chromatography(GC). The TFAs contents and compositions of four types of typical foods were determined with GC. A method for the determination of TFAs in food by GC-MS technology also was developed for qualitative. quantitative analysis. The main results are as follows:1.The articles studied pretreatment methods of TFAs in foods determination,through the comparison of different methods, selection and optimization. And a pretreatment method for extraction by fatty alkali saponification and methyl esterification by three boron fluoride was been developed, which is suitable for different types of TFAs in foods considered fully of both samples, in short, medium, long chain fatty acid extraction, saponification and methylation.2. A capillary chromatographic column of HP-88(30m×0.25mm×0.20μm) was used for separating a variety of fatty acid methyl ester quickly with GC. By this column chromatographic separation time was shorten from70mins to35mins, and some difficulties from separating by100m column were avoided. At the same time, A method for the determination of trans fatty acids by GC-MS was established,and all the components were separated through DB-225ms in65mins. It solves the problem in the method by GC, and improves the reliability of the analysis results.3. The GC method, which has been applied in determination of TFAs in foods, was successful for FA separation. The RSD was within8.0%, the recovery85.3%～91.8%, and the limit of detection is O.Olg/100g. The method is simple, rapid, sensitive and can be applied in the lab. The pretreatment method for extraction by fatty alkali saponification and methyl esterification by three boron fluoride is accurate and efficient,and it solves the problem of fat-extracting incompletely in SN/T1945-2007.The method can be used for different types of food,and it overcomes the limit in GB/T22110-2008which does not apply to animal fats and animal oils containing trans fatty acids in foods determination of.4. The articles collected representative four categories of39kinds of high-fat content foods, and analyzed the distribution and content of TFAs in foods. The research shows that TFAs are common in foods, mainly in t-C16:1、t-C18:1and t-C18:2. Some foods, which contain ingredients such as "hydrogenated vegetable oil", are high in TFAs. need cautiously treated required in the preparation of food nutrition labels. And because of the wide use of edible oil and high temperature processing, part of the traditional processed foods are also high in TFAs. We need adequate intake of these foods.