Actin Determination as a Means of Calculating the Meat Content of Meat Products

ABSTRACT Double radioisotope labelling and peptide isolation can be used to determine the amount of actin in protein mixtures. Muscle samples from a variety of animals have similar actin contents as measured by this method and two common meat extenders, soy and milk protein, contain no material measured as actin. The potential usefulness of actin determination as a measure of the meat protein content of meat products was examined. Curing processes lead to a reduced apparent actin content in meats as determined by double labelling. However, it was found that there was a significant correlation between the ground beef derived protein content of extended ground beef samples and the actin content per unit protein when double labelling was used to determine the actin content of ground beef preparations containing various amounts of soy protein.