[Detection of plasticizers in edible essence by near-infrared spectrometry]

Based on the initial near-infrared spectrum of edible essence samples and its mixture with DEHP and DINP, we chose the wavelength ranges of 8,800 - 8,540 and 7,500 - 5,085 cm-1 to use the principal component analysis (PCA) method to distinguish these three types of samples. The correct rate of the identification is proved to be 100%. Meanwhile, we measured the content of DEHP and DINP (with the concentration ranging between 0 and 100 mg.kg-1) in the edible essence and established the quantitative analysis model by using partial least squares (PLS). It was found that the relative errors of the prediction results of DEHP and DINP are -1.23% - 3% and -1% - 3.6%, respectively, and the relative root-mean-square errors of prediction (RRMSEP) of them are 1.39 and 0.98, respectively. This study provides a simple, rapid and accurate method to detect the additive dosage of plasticizing agents in edible essence in the food industry.