Analysis of the volatile fraction of lamb fat tissue: influence of the type of feeding

Abstract

The volatile compounds of subcutaneous fat tissue of lambs were analysed by dynamic headspace sampling-high resolution gas chromatography-mass spectrometry (DHS-HRGC-MS). The animals were produced in six European countries according to local traditional rearing conditions and they were classified into two groups according to the predominant type of feed consumed (pasture or concentrate). The analysis showed that the pasture-fed lambs clearly differed from the concentrate-fed lambs. Fat samples from the pasture-fed lambs desorbed greater quantities of compounds of green leaf tissue origin such as long-chain alkanes, C7 aldehydes and 2,3-octanedione. The fat samples from the concentrate-fed lambs desorbed greater quantities of short-branched and non-branched acids and methyl ketones. The present results suggest that 2,3-octanedione or long-chain alkanes, and 4-heptanone or 2-octanone in the lamb subcutaneous fat tissue are specific of feedings consisting predominantly of pasture and concentrate, respectively. These compounds could be used as markers of the feeding background of the animal.