Ozen Banu F, Weiss Ilan, Mauer Lisa J
Food Science Department, Purdue University, 745 Agriculture Mall Drive, West Lafayette, IN 47907, USA.
J Agric Food Chem. 2003 Sep 24;51(20):5871-6. doi: 10.1021/jf034245h.
Fourier transform infrared spectroscopy (FT-IR) methods and common chemometric techniques [including discriminant analysis (DA), Mahalanobis distances, and Cooman plots] were used to classify various types of dietary supplement oils (DSO) and less expensive, common food oils. Rapid FT-IR methods were then developed to detect adulteration of DSO with select common food oils. Spectra of 14 types of DSO and 5 types of common food oils were collected with an FT-IR equipped with a ZnSe attenuated total reflectance cell and a mercury cadmium telluride A detector. Classification of DSO and some common food oils was achieved successfully using FT-IR and chemometrics. Select DSO were adulterated (2-20% v/v) with the common food oils that had the closest Mahalanobis distance to them in a Cooman plot based on the DA analysis, and data were also analyzed using a partial least-squares (PLS) method. The detection limit for the adulteration of DSO was 2% v/v. Standard curves to determine the adulterant concentration in DSO were also obtained using PLS with correlation coefficients of >0.9. The approach of using FT-IR in combination with chemometric analyses was successful in classifying oils and detecting adulteration of DSO.
傅里叶变换红外光谱（FT-IR）方法和常见的化学计量技术[包括判别分析（DA）、马氏距离和库曼图]被用于对各类膳食补充剂油（DSO）和价格较低的常见食用油进行分类。随后开发了快速FT-IR方法，以检测DSO中掺入特定常见食用油的情况。使用配备硒化锌衰减全反射池和碲镉汞A探测器的FT-IR收集了14种DSO和5种常见食用油的光谱。利用FT-IR和化学计量学成功实现了DSO和一些常见食用油的分类。根据判别分析，在库曼图中选择与DSO马氏距离最近的常见食用油对其进行掺假（2-20% v/v），并使用偏最小二乘法（PLS）对数据进行分析。DSO掺假的检测限为2% v/v。使用PLS还获得了用于测定DSO中掺假物浓度的标准曲线，相关系数>0.9。将FT-IR与化学计量分析相结合的方法在油类分类和检测DSO掺假方面取得了成功。
