Ruminant fat volatiles as affected by diet. A review.

Volatile compounds in meat have been widely studied for their favourable or undesirable effects on meat flavour, or for their potential use in tracing the animal feeding system. To date, the chemical mechanisms causing the appearance of volatile compounds in meat have been largely understood. Several variables are involved in the accumulation of volatiles in animal tissues and among them animal diet plays a key role. The purpose of the present review is to highlight the effects of different dietary regimes (concentrate, green grass and fat-enriched diets) on the appearance of fat volatile compounds in ruminant meat. Grain-based diets induce greater accumulations in meat of branched-chain fatty acids, some aldehydes, and lactones while meat fat from grazing animals contains high levels of phenols, terpenes, indoles and sulphur compounds. Fat-enriched diets exert their effect mainly on those volatiles which originate from polyunsaturated fatty acids. Cooking procedures have been considered for their contribution to fat volatiles in meat by reactions induced by high temperatures.