几种常见植物油中主要醛类物质含量随温度的变化规律研究

目的建立气相色谱-质谱联用技术(gas chromatography-mass spectrometry,GC-MS)测定常用5种植物油中主要醛类物质含量的分析方法,探究植物油中主要醛类物质含量随温度变化的规律,同时测定5种植物油的不饱和度。方法采用碘值法测定了5种植物油的不饱和度,利用GC-MS法测定植物油中主要醛类物质丙烯醛、己醛、庚醛的含量,并研究其随温度变化的情况。结果 5种植物油的碘值由大到小依次为红花籽油、菜籽油、棉籽油、葵花籽油、大豆油,随着温度升高,植物油中主要醛类物质的含量逐渐增多,以丙烯醛的含量最高。结论本方法操作简便,灵敏度较高,适用于植物油中醛类物质的含量测定。在植物油加热过程中,应尽可能缩短加热时间、控制加热温度,以减少醛类物质的生成。

Study on the changing law of main aldehydes content with temperature in several kinds of common vegetable oils

Objective To establish a method for the determination of main aldehydes content in five vegetable oils with GC-MS and study on their changing law of temperature. The unsaturation dagree of fatty acids in the vegetable oils was also determined. Methods The method of Iodium value was applied to determin the unsaturation degree of fatty acids in vegetable oils. The contents of acrolein , hexanal, heptaldehyde in vegetable oils were measured by GC-MS. Their changing laws of temperature were also researched. Results The Iodium value of vegetable oils from big to small is safflower oil, rapeseed oil, cottonseed oil, sunflower oil, soybean oil. The main aldehydes content in vegetable oils incerased with increasing temperature. The highest content is acrolein. Conclusion This method is simple and sensitive, which is suitable for determination of aldehydes content in vegetable oils. The heating time of vegetable oil should be shortened as much as possible to control the heating temperature so as to reduce the generation of aldehydes.