Multielement (H, C, N, O, S) stable isotope characteristics of lamb meat from different Italian regions

The study focuses on the H-2/H, C-13/C-12, N-15/N-14, O-18/O-16 and S-34/S-32 values of defatted dry matter (DFDM) and on the H-2/H, C-13/C-12 and O-18/O-16 values of the fat fraction of meat samples from various lamb types reared in seven Italian regions, following different feeding regimes (forage, concentrate, milk). The C-13/C-12 (r = 0.922), H-2/H (r = 0.577) and O-18/O-16 (r = 0.449) values of fat and DFDM are significantly correlated, the fat values being significantly lower for C and H and higher for O than for DFDM values and the differences between the two fractions not being constant for different lamb types. The feeding regime significantly affected the C-13/C-12, N-15/N-14, O-18/O-16 and H-2/H of fat. The DFDM H-2/H, and O-18/O-16 values, excluding an outlier, are significantly correlated with the corresponding values in meteoric waters, thus allowing us to trace the variability of geoclimatic factors. N-15/N-14 is influenced by pedoclimatic conditions, whereas S-34/S-32 is influenced by the sea spray effect and the surface geology of the provenance area. By applying stepwise linear discriminant analysis only the H-2/H of fat was found not to be significant and 97.7% of the samples were correctly assigned to the lamb type and more than 90% cross-validated. With the feeding regime, 97.7% of the samples were both correctly assigned and cross-validated using a predictive model including C-13/C-12, N-15/N-14, O-18/O-16 and S-34/S-32 of DFDM and O-18/O-16 of fat. Copyright (C) 2009 John Wiley & Sons, Ltd.