Changes in key odorants of sheep meat induced by cooking

Application of the Aroma Extract Dilution Analysis on two extracts prepared from cooked and raw lean sheep meat revealed 4-ethyloctanoic acid (mutton-like), trans 4,5-epoxy(E)-2-decenal (metallic), (Z)-1,5-octadien-3-one (geraniumlike) and (E,E)-2,4-decadienal (deep fried) as important odorants in the cooked as well as in the raw meat, thereby indicating the important role of the raw meat as source of sheep meat odorants. 4-Hydroxy-2,5-dimediyl-3(2H)- furanone and 2-acetyl-l-pyrroline as well as 2-aminoacetophenone were among the few aroma compounds, which were clearly increased in their Flavor Dilution (FD) factors by the cooking procedure. A stable isotope dilution assay showed that 4-ethyloctanoic acid was by a factor of 4 higher in uncooked intramuscular fat as compared to uncooked adipose tissue, in which 4,5-epoxy-(E)-2-decenal and further lipid degradation were shown to be the most odor-active compounds. The cooking procedure did not much alter the concentration of 4-ethyloctanoic acid.