Marbling, or white flecks of fat within the meat muscle, is often evaluated on the cut surface of the rib-eye or loinieye. The most commonly used method for evaluating marbling is visual comparison with published standards. Marbling is most important in influencing the sensory attributes of flavor and juiciness and to a limited extent the tenderness of the product. Of these attributes, flavor may be the characteristic that is most dependent on marbling. Because most of the species-associated flavor compounds are carried in the lipid fraction of the muscle tissue, products with higher amounts of marbling are often described as having more intense flavor.
Retail cuts that have very little marbling (practically devoid or traces) are likely to result in cooked products that lack flavor and juiciness when eaten; this is especially true for retail cuts (beef steaks, pork and lamb chops) that are prepared by dry heat cookery methods. When cuts are prepared with moist heat cookery, marbling degrees of traces or slight should be sufficient to make palatability acceptable. Retail cuts with excessive marbling may result in a cooked product with a greasy or tallow-like flavor and a high fat and caloric content.
Marbling that is fine-textured (small flecks) and uniformly distributed is preferred over marbling that appears as large, coarse flecks of intramuscular fat. If marbling enhances juiciness by serving as a "lubricant" around muscle bundles, then it should be uniformly and finely dispersed throughout the lean.