Initial studies into the characterisation of ripening stages of Emmental cheeses by mid-infrared spectroscopy.

摘要

Experimental Emmental cheese samples were analysed to evaluate the potential of mid-IR spectroscopy to follow ripening. Batches of the cheese were sampled at 7 different ripening stages and analysed. IR spectra were obtained by placing cheese slices directly over the attenuated total reflectance crystal. Analysis of variance showed significant (P <= 0.05 ) absorbance changes between spectral sets in the regions assigned to vibrations of alcohol, amide and hydrocarbon chains. Principal component analysis (PCA) allowed classification of 4 groups based on when the samples ripened: 21, 27 and 34 days; 51 and 58 days; 65 days; and samples at the end of the ripening (mould opening, about 85 days). Using general discriminant analysis of spectral data, it was not possible to correctly distinguish samples according to the 7 dates of sampling, but samples belonging to the 4 groups identified by PCA could be predicted well using the regression model.