婴幼儿奶粉的FTIR分析与鉴定

Analysis and Discrimination of Infant Powdered Milk via FTIR Spectroscopy

采用傅里叶变换红外光谱法（FTIR）获得了六种婴幼儿奶粉的红外光谱及其二阶导数谱。奶粉中的脂肪（1747，2854，2926cm^-1）、蛋白质（1658，1540cm^-1）和糖（1200～900cm^-1）等主要营养成分具有明显的红外指纹特征。麦芽糊精、蔗糖和乳糖同样具有明显的指纹特征，随着添加量的不同而改变。同一厂家不同类型的婴幼儿奶粉，脂肪、蛋白质和糖含量差异较大，红外光谱差异较显著；不同厂家相同类型的婴幼儿奶粉的红外光谱差异较小，但其二阶导数谱具有明显的指纹特征。该方法简便、快速、可直观的评价奶粉的品质优劣。

Six kinds of infant powdered milk were identified by Fourier transform infrared spectra （FTIR） and their corresponding second derivative infrared spectra. The main nutritious components such as lipid （1 747, 2 854 and 2 926 cm^-1 ）, protein （1 658 and 1 540 crn 1）, and carbohydrate（1 200-900 cm^-1） of had distinct fingerprint characteristics of FTIR spectra. Maltodextrin, sucrose and lactose also had obvious spectral characteristics, which changed with different added content. For the samples from the same factory but with different sorts, there was some dissimilarity in the relative intensities of infrared absorption peaks due to the difference in fat, protein and carbohydrate. For the samples of the same sort but from different factories, there are certain similarities in the IR spectra, however, the second derivative infrared spectra present different fingerprint characteristics. This analytical method is fast and direct for evaluating the quality of infant powdered milk.