Second-derivative FT-IR spectroscopy, an alternative approach in milk and dairy product testing - A model study

A model study has been carried out to explore the potential benefit's of using second-derivative FT-IR spectra, instead of normal FT-IR spectra, to analyse milk and milk products to their fat and protein content. It was found that the spectral interpretation is simplified significantly by computing 2nd-derivative spectra from the normal spectra. Contributions of the main components to each other's signal intensities reduced to a large extent in 2nd-derivative spectra. As a result simplified models could be used to estimate fat and protein contents, from these spectra, for a calibration set of raw milk samples.