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

Abstract

The study focuses on the ²H/H, ¹³C/¹²C, ¹⁵N/¹⁴N, ¹⁸O/¹⁶O and ³⁴S/³²S values of defatted dry matter (DFDM) and on the ²H/H, ¹³C/¹²C and ¹⁸O/¹⁶O 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 ¹³C/¹²C (r = 0.922), ²H/H (r = 0.577) and ¹⁸O/¹⁶O (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 ¹³C/¹²C, ¹⁵N/¹⁴N, ¹⁸O/¹⁶O and ²H/H of fat. The DFDM ²H/H, and ¹⁸O/¹⁶O values, excluding an outlier, are significantly correlated with the corresponding values in meteoric waters, thus allowing us to trace the variability of geoclimatic factors. ¹⁵N/¹⁴N is influenced by pedoclimatic conditions, whereas ³⁴S/³²S is influenced by the sea spray effect and the surface geology of the provenance area. By applying stepwise linear discriminant analysis only the ²H/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 ¹³C/¹²C, ¹⁵N/¹⁴N, ¹⁸O/¹⁶O, ³⁴S/³²S of DFDM and ¹⁸O/¹⁶O of fat. Copyright © 2009 John Wiley & Sons, Ltd.