Determination of Thermally Induced trans-Fatty Acids in Soybean Oil by Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy and Gas Chromatography Analysis
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- 作者：An Li ; Yiming Ha ; Feng Wang ; Weiming Li ; Qingpeng Li
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：2012
- 出版时间：October 24, 2012
- 年：2012
- 卷：60
- 期：42
- 页码：10709-10713
- 全文大小：248K
- 年卷期：v.60,no.42(October 24, 2012)
- ISSN：1520-5118
文摘
The intake of edible oil containing trans-fatty acids has deleterious effects mainly on the cardiovascular system. Thermal processes such as refining and frying cause the formation of trans-fatty acids in edible oil. This study was conducted to investigate the possible formation of trans-fatty acids because of the heat treatment of soybean oil. The types of trans-fatty acids in heated soybean oil are determined by attenuated total reflectance Fourier transform infrared spectroscopy and gas chromatography鈥搈ass spectrometry methods. The effects of the heating temperature on the trans-fatty acids in soybean oil were evaluated using gas chromatography flame ionization detection analysis. Results show that heat treatment at 240 掳C causes the formation of trans-fatty acids in soybean oil and the amount of trans-fatty acids increases with heating time. The only peak observed at 966 cm鈥? of the samples indicates the formation of nonconjugated trans isomers in the heated soybean oil. The major types of trans-fatty acids formed were trans-polyunsaturated fatty acids. Significant increases (P < 0.05) in the amounts of two trans-linoleic acids (C18:2-9c,12t and C18:2-9t,12c) and four trans-linolenic acids (C18:3-9c,12c,15t, C18:3-9t,12c,15c, and C18:3-9t,12t,15c/C18:3-9t,12c,15t) in soybean oil heated to temperatures exceeding 200 掳C were compared with those of the control sample. The heating temperature and duration should be considered to reduce the formation of trans-fatty acids during thermal treatment.