动植物油脂中反式脂肪酸测定方法的建立

目的建立适合国内条件的动植物油脂中反式脂肪酸测定方法,为国标方法提供依据。方法选择普通植物油、动物油和氢化植物油三个大类共9种动植物油脂样品,参照国际标准经部分修改,建立了适合国内条件的反式脂肪酸气相色谱分析及用面积归一法定量的测定方法,并进行了重复性测定和实验室间的验证。结果在实验条件下,油脂中脂肪酸可以得到很好的分离;除个别含量极低的脂肪酸外,各脂肪酸组分10次分析结果的相对标准偏差均小于10%,其中反式脂肪酸总和的RSD值在豆油和氢化豆油中分别是2.0%和0.3%;实验室间验证结果也表明,该方法在不同实验室间的结果有很好的一致性,豆油、氢化豆油、猪油三种样品的反式脂肪酸总和的RSD值分别是5.0%、1.1%和4.6%,均远小于10%。结论该检测方法实验室内和实验室间的精密度均较高,且所需仪器比较普及,操作步骤简单易行,分析时间短,适合国内开展,可作为我国动植物油脂反式脂肪酸的测定方法之一。

ESTABLISHMENT OF THE METHOD FOR TRANS FATTY ACIDS DETERMINATION IN ANIMAL AND VEGETABLE FATS AND OILS

Objective To establish the gas chromatography (GC) method for determining trans fatty acids in animal and vegetable fats and oils, and to provide basis for national standard. Method Nine different fats and oils including vegetable oils, hydrogenated vegetable oils and animal fats were chosen as samples. The analysing conditions were optimized with reference to international standards, and the repeatability of the method in and between laboratories were proceeded too. Results Different fatty acids could be separated successfully under this analysing condition. The RSD of total trans fatty acids in inner laboratory was 2.0% in soybean oil and 0.3% in hydrogenated soybean oil and the RSD of total trans fatty acids between laboratory was 5.0%、1.1%和 4.6% for soybean oil, hydrogenated soybean oil and lard respectively. Conclusion The precision of this method is high in and between laboratories, and the method is easy, so it can be used to analyse the trans fatty acids contents in animal and vegetable fats and oils.