甘油三酯指纹图谱在食用植物油掺伪鉴别中的应用

Application of Triglyceride Fingerprint in Identification of Adulterated Edible Oil

为了构建橄榄油、大豆油、花生油、玉米油、葵花籽油、菜籽油的甘油三酯指纹图谱,采用反相液相色谱-蒸发光散射检测器对6种食用植物油中甘油三酯进行分离,图谱数据采用平均矢量法导入中药色谱指纹图谱相似度评价系统(2012版),分析指纹图谱的相似度。结果表明,同一种食用植物油不同品牌间的甘油三酯指纹图谱相似度高,不同食用植物油的甘油三酯指纹图谱差异明显。橄榄油与玉米油、大豆油及葵花籽油相似度比较低,分别为0.233、0.086、0.073;与菜籽油、花生油相似度较高,分别为0.830和0.776。当橄榄油中掺入10%的大豆油、玉米油或葵花籽油时,其指纹图谱相似度均低于0.90。橄榄油中掺入菜籽油后其相似度变化不明显。采用面积归一法对指纹图谱特征峰进行分析,掺入比例的检出限低于15%。甘油三酯指纹图谱与面积归一法相结合,可作为食用植物油鉴定及掺伪鉴别的有效手段。

To construct the triglyceride fingerprint of olive oil,soybean oil,peanut oil,corn oil,sunflower oil and rapeseed oil,triglycerides of the six edible vegetable oils were isolated by HPLC-ELSD.The data was imported into the traditional Chinese medicine chromatographic fingerprint similarity evaluation system(version 2012)by the average vector method,and the similarity of the fingerprint was analyzed.The results showed that the fingerprint profile of triglycerides was similar among different brands of the same edible vegetable oil,while was significantly different among various edible vegetable oils.Olive oil had low similarity with corn oil,soybean oil,or sunflower oil,and the similarity was 0.233,0.086 and 0.073,respectively;however,it had high similarity with rapeseed oil and peanut oil,and the similarity was 0.830 and 0.776,respectively.When olive oil was mixed with 10% corn oil,soybean oil,or sunflower oil,the similarity of triglyceride fingerprint was less than 0.90,but the similarity change was not obvious when mixed with rapeseed oil.Area normalization method was used to analyze the characteristic peak of fingerprint,and the detection limit of adulteration ratio was less than 15%.The combination of triglyceride fingerprint and area normalization method can be an effective method for identification the adulteration of edible vegetable oil.