Marbling also known as intramuscular fat is the white flecks and streaks of fat found within the eye of the muscle.
Marbling in Meat...
British and European breeds of cattle are known for their tenderness, Wagyu cattle are renown for their marbling attributes. The name Wagyu refers to "Wa" meaning Japanese and "gyu" meaning cow and is a Japanese breed derived from native Asian cattle that is renowned for their marbling characteristics. Wagyu beef has a unique flavor when cooked, this is due to the marbling (intramuscular fat) that is distributed throughout the various muscles.
How is beef graded for marbling?
Australian beef is graded by AUS-MEAT on a scale of 0 (no visual marbling) to 9 (extensive visual marbling). The AUS-MEAT Marbling System provides an indication of the amount of marbling in beef. The MSA Marbling System provides an additional indication of the fineness of distribution and the size of marbling pieces. The AUS-MEAT Marbling Evaluation System and the MSA Marbling Evaluation System can be used in harmony to provide more detail about the product. A variety of components such as age of the animal, diet (grain or grass fed) along with the breed of the animal influence the level of marbling. Generally beef cuts from the forequarter and loin of the animal exhibit higher levels of marbling compared to butt cuts from the hindquarter.