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

Citation
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
Citations number
31
Categorie Soggetti
Agricultural Chemistry","Chemistry & Analysis
Journal title
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
ISSN journal
00218561 → ACNP
Volume
49
Issue
3
Year of publication
2001
Pages
1404 - 1409
Database
ISI
SICI code
0021-8561(200103)49:3<1404:COTGOO>2.0.ZU;2-2
Abstract
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.