Compounds in the environment following removal of animal guts that contribute to perception of odours:
(a) Oct-1-en-3-one, a ketone resulting from the interaction of Fe2+ ions and degraded lipid, commonly characterised as “metallic” smelling;
(b) 3-Methyl-1H-indole, known as skatole, associated with faecal odour, but is also present in lower concentrations in flowers like jasmine and orange blossom;
(c) ammonia, derived from urea, associated with a strong, pungent odour;
(d) butane-1,4-diamine, known as putrescine and
(e) Pentane-1,5-diamine, known as cadaverine, derived from amino acids in the body, are both characterised as putrid;
(f) Fufural and
(g) HMF, produced from thermal degradation of glucose, are characterised by almond-like, buttery, caramel odours;
(h) 2,5-Dimethylpyrazine and
(i) 2-Acetylpyridine, produced from thermal degradation of glycine, are characterised by sweet, nutty and roasted odours.