Derivation of an equation to estimate marrow content of bovine cervical vertebrae

Marrow content of bovine cervical vertebrae from Choice- and Select-grade carcasses weighing 294 to 343 kg was determined so that a method to monitor the amount of marrow in meat from advanced meat/bone separation machinery and recovery (AMR) systems could be developed. The marrow determination requires cleaning and then ashing bones. Because a large difference in ash content of bone and bone marrow exists and because cartilage content of cervical vertebrae in Choice and Select beef is relatively constant, it was possible to derive the following equation: Weight of marrow = [weight of cartilage (% ash in cartilage - % ash in bone) + % ash in bone (total weight) - (total ash)]/[(% ash in bone - % ash in marrow)]. Constants for ash in fresh bone, marrow, and cartilage were 58.51, .57, and 2.14% with SD of 2.23, .15, and .30%, respectively. A cartilage content of 9.5% along with cervical vertebrae weight and total ash weight were also used to calculate 33.9% marrow in cervical vertebrae. Means for marrow pressed or centrifuged from bovine cervical vertebrae were lower than those obtained from the equation. Therefore, pressing and centrifuging left some marrow in spongy bone. Our ashing method for determining the amount of marrow in whole cervical vertebrae should be useful for determining marrow remaining in cervical vertebrae of bone cakes from AMR systems. Percentage ash in pressed bones is higher and the calculated marrow content is lower when pressed bones are compared to cervical vertebrae that are not pressed. The amount of marrow in whole cervical vertebrae minus the amount left in cervical vertebrae from bone cakes equals the amount in meat from AMR systems.