Characterization of the geographical origin of pecorino sardo cheese by casein stable isotope (C-13/C-12 and N-15/N-14) ratios and free amino acid ratios
G. Manca et al., Characterization of the geographical origin of pecorino sardo cheese by casein stable isotope (C-13/C-12 and N-15/N-14) ratios and free amino acid ratios, J AGR FOOD, 49(3), 2001, pp. 1404-1409
The stable isotope ratios (C-13/C-12 and N-15/N-14) of casein measured by i
sotope ratio mass spectrometry. (IRMS) and some free amino acid ratios (His
/Pro, Ile/Pro, Met/Pro, and Thr/Pro) determined by HPLC in samples of ewes'
milk cheese from Sardinia, Sicily, and Apulia were found to be parameters
independent of ripening time. Multivariate data treatments performed by app
lying both unsupervised (principal component analysis and cluster analysis)
and supervised [linear discriminant analysis (LDA)] methods revealed good
discrimination possibilities for the cheeses according to place of origin.
In this respect, particularly significant were the variables Ile/Pro, Thr/P
ro, C-13/C-12, and N-15/N-14 ratios on which basis 100% discrimination and
classification of the samples by LDA was obtained.