Genetic and nutritional effects on lamb flavor

Abstract

Annual per capita consumption of lamb in the United States has declined throughout the last 40 yr to 0.32 kg on a retail weight basis. In a recent survey, consumers identified taste as one of the most important factors when purchasing meat products and ranked lamb last among other meats (beef, chicken, fish, pork, turkey, and veal) for taste and overall preference. Research has shown that meat flavor resides in the water-soluble fraction but that species-specific flavors are located in the lipid fraction of meat. In lamb, branched chain fatty acids of 8 to 10 carbons are believed to strongly contribute to its characteristic flavor. Oxidation products from long-chain unsaturated fatty acids also contribute to flavor intensity in lamb. Research has shown differences in flavor intensity due to breed or sire breed; however, the results have been inconsistent and depend on the type of sensory panel used to evaluate the product. Lamb from fine-wool breeds were reported to have a more intense flavor than coarse-wool breeds; whereas lamb from hair sheep was described as being more desirable for flavor intensity than coarse-wool breeds. Lamb flavor is also impacted by nutrition of the lambs before harvest. Research has shown that finishing lambs on pasture increases lamb flavor and off-flavors. Grain feeding alone or supplemented while on pasture typically produces lamb with more acceptable flavors than on pasture alone. However, the extent that flavor intensity is altered depends on the type of forage and grain consumed. Feeding protected lipid supplements to alter fatty acid composition can reduce mutton flavor but can increase off-flavors due to oxidation. Genetics and nutrition impact lamb flavor. However, more research is needed to determine ways to manipulate these factors to alter lamb flavor and to increase its consumption in the human diet.