Evaluation of the application of attenuated total reflectance-Fourier transform infrared spectrometry (ATR-FTIR) and chemometrics to the determination of nutritional parameters of yogurt samples

摘要

A critical evaluation of the application of attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) and partial least squares (PLS) to the determination of several nutritional parameters, such as the energetic value and the carbohydrate, protein and calcium contents, in commercially available yogurt samples was carried out. To this end, a highly heterogeneous population of 48 samples covering a wide range of yogurts obtained from the Spanish market was used. After correcting the spectra, hierarchical cluster analysis was performed in order to select a representative calibration set and the corresponding validation sample set. Different PLS models and several spectral windows were tested in order to evaluate their prediction capabilities for the validation set. For all nutritional parameters, with the exception of fat content, the procedure developed here provided good precision; the values obtained complied with the statutory values declared by the US FDA.