Discrimination of grated cheeses by Fourier transform infrared spectroscopy coupled with chemometric techniques

Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), combined with chemometric analysis, was used to classify grated Parmigiano-Reggiano cheese from other grana-type cheeses (so called for their granular texture) from Italy, central and northern Europe. A total of 36 grated cheese samples (21 Parmigiano-Reggiano and 15 Italian and non-Italian non-Protected Designation of Origin) were analysed. Samples were scanned in the range of 4000e700 cm1. Two attenuated total reflectance accessories were utilised. Linear discriminant analysis (LDA) and principal component analysis were used to analyse spectral data after applying a moving windows algorithm for wavelength selection. Both methods successfully classified the four classes of grated cheese samples, and LDA was found to be the best chemometric approach. ATR-FTIR spectroscopy coupled with LDA is a promising technique, and merits further investigation as a reliable and rapid classification tool that does not require chemical analyses for discrimination of cheese.