New applications of MIR spectrometry: Quality Assurance practices with new parameters in raw milk analysis

Abstract

Mid InfraRed (MIR) spectrometry is traditionally applied for quantitative determination of major components of milk such as fat, protein or lactose. For these “traditional” parameters, MIR Filter apparatus techniques have been used for a long time. They used simple models to predict these parameters using a very low number of wavelength. Recently, Fourier-transform infrared spectroscopy (FTIR), a more complex technique, has been proposed. FTIR apparatus collect high-spectral-resolution data over a wide spectral range. This confers a significant advantage over a dispersive spectrometer, which measures intensity over a narrow range of wavelengths at a time. A Fourier transform (a mathematical process) is required to convert the raw data into the actual spectrum. Thanks to additional prediction models developed by researchers and instrument manufacturers, FT-IR spectra can be used beyond quantitative determination of major components of milk such as fat, protein or lactose, to measure other dairy components such as fatty acids and minerals, and also to measure qualitative parameters. However, traditional calibration procedures developed with filter apparatus need to be adapted to respond to the more complex models used. This document focuses on the required checks with the implementation of new quantitative applications and how the quality assurance of the results can be assured. New approaches are presented