Relationship between Odour-active Compounds and Flavour Perception in Meat from Lambs Fed on Different Diets

Abstract

The aim of this article is to summarise the main effects of the rearing system (feeding diets in in the steppe and the highlands) on the flavour of the meat. To identify the most important aroma compounds in meat, we assess the meat from two groups of lambs (Rembi breed) feeding on pasture supplemented by hay in a highland area and pasture supplemented with concentrate in a steppe area, and with a free access to water. The study was carried out in spring of 2014. After slaughter, samples of the Longissimus thoracis were removed, cooked and subjected to a dynamic headspace-solid phase extraction (DHS-SPE) and gas chromatography–olfactometry (GC–O). Most of the important odorants were aldehydes and ketones. To evaluate the effect of finishing diet on carbonyl compounds, a derivatization of the headspace carbonyls using o-[(2,3,4,5,6-pentafluorophenyl)methyl]hydroxylamine hydrochloride (PFBHA) and analysis by GC–MS was conducted. Diet affected aliphatic saturated aldehydes. The meat from lambs finished on pastures, without a concentrate supplement in the highland, had very low concentrations of lipid-derived unsaturated aldehydes and ketones and Strecker aldehydes, possibly because of the protective effect of antioxidants that occur in the diet naturally. Lamb flavour was related to the concentration of heptan-2-one, hexanal, 2 méthyl 3 furanthiol and oct-1-en-3-one, but there werre not rancid or undesirable flavours related to the abundance of carbonyl compounds.