Animal Production Origins of some Meat Color and Flavor Attributes

Abstract

Although pastoral finishing systems are inexpensive, they result in some quality outcomes that set meat from such animals apart from the grain-finished equivalent. These outcomes, including meat and fat color, fat composition, meat pH, and odor/flavor profiles, have a chemical basis that can be traced to pastoral production. The color of raw meat is indirectly linked to pasture composition in several ways. Meat color stability, i.e., maintenance of oxymyoglobin (bright-red) rather than its auto-oxidation to metmyoglobin (brown), is helped by dietary antioxidants, like tocopherol. Tocopherol is abundant in green pasture but not grain. The pigment carotene, another antioxidant also abundant in pasture, is the cause of variably yellow fat in pasture-finished cattle. Although ruminants tend to hydrogenate unsaturated fatty acids present in the diet, some fatty acids escape this fate and are incorporated directly in storage triglycerides. As a result, the melting points of storage fats can differ due to diet, as can the pattern of fat oxidation during cooking. The latter results in different odor/flavor profiles, which may be partly responsible for ‘pastoral’ flavor. Flavor profiles also differ with meat pH, which in turn has links to diet and production systems. Work with sheep suggests that the fecal-smelling compound skatole (3-methylindole) is often generated by the excess protein in pastoral diets. Skatole can accumulate in storage fats, and may be a major contributor to pastoral flavor. These and other meat quality issues and their chemical links to production and diet are examined in this review