基于维生素E组成的植物油掺棕榈油鉴别研究

Identification of vegetable oils adulterated with palm oil based on vitamin E composition

目的 建立基于维生素E组成的植物油掺棕榈油鉴别方法。方法 采用正相高效液相色谱-荧光检测方法测定大豆油、菜籽油、葵花籽油、橄榄油、玉米油、棕榈油等植物油中α-、β-、γ-、δ-生育酚和α-、β-、γ-、δ-生育三烯酚8种维生素E组成,使用主成分分析(principal component analysis,PCA)构建植物油品种识别和掺假油鉴别模型。结果 不同种类植物油中的生育酚和生育三烯酚的组成差异很大,棕榈油中含高水平的生育三烯酚,这成为其区别于其他5种植物油的一个重要特点。结合PCA可以将棕榈油、葵花籽油、大豆油、橄榄油等相互区分开来。采用PCA建立了针对菜籽油、大豆油、橄榄油、葵花籽油、玉米油中掺棕榈油的鉴别模型,当棕榈油掺杂浓度大于等于25%时,模型可准确识别出掺假油。结论 采用正相高效液相色谱-荧光检测方法测定植物油中α-、β-、γ-、δ-生育酚和α-、β-、γ-、δ-生育三烯酚8种维生素E组成,结合化学计量学法,可实现对常见植物油掺棕榈油的鉴别。

Objective To establish a chemometric identification method of vegetable oils adulterated with palm oil based on the composition of vitamin E.Methods The α-,β-,γ-,δ-tocopherol and α-,β-,γ-,δ-tocotrienol concentrations of soybean oil,rapeseed oil,sunflower oil,olive oil,corn oil and palm oil were determined by normal-phase high performance liquid chromatography with fluorescence detection.The identification model of vegetable oil varieties and adulterated oil were built by the principal component analysis(PCA).Results The compositions of tocopherols and tocotrienols in different kinds of vegetable oils was very different.Palm oil contained high levels of tocotrienols,which was an important characteristic that distinguishes it from the other 5 kinds of vegetable oils.Palm oil,sunflower seed oil,soybean oil and olive oil could be distinguished from each other by PCA.A qualitative model was established for the verification of rapeseed oil,soybean oil,olive oil,sunflower oil and corn oil adulterated with palm oil.When the adulterated ratio of palm oil was greater than or equal to 25%,the adulterated oils could be identified.Conclusion Normal-phase high performance liquid chromatography with fluorescence detection is used to determine the content of α-,β-,γ-,δ-tocopherol and α-,β-,γ-,δ-tocotrienol in vegetable oils.Combined with chemometrics,the identification of common vegetable oils adulterated with palm oil can be realized.