Meat, as defined for labelling purposes, is restricted to skeletal muscle with naturally adherent fat and connective tissue. A meat content declaration of meat product is required by law. Undeclared blood proteins are alleged to have been used in processed meats as emulsifiers. This would also have the effect of increasing the nitrogen content, and as meat content is measured by determining nitrogen, such addition would falsify the true meat content or disguise added water. Declaration of ingredients from blood is also important to consumers who might wish to avoid consuming them. A method is therefore required to detect the undeclared addition of blood products to processed meats, particularly blood products from bovine and porcine animals, which are the main commercial sources of blood proteins.
Research Approach:<BR> This research involved the development of an antibody based method to detect the blood protein albumin. Albumin is the most prevalent blood protein in both blood plasma and serum, and is a heat stable molecule making it an ideal target for this assay. The project aimed to generate antibodies to detect cooked albumin from bovine and porcine sources and then evaluate the use of these antibodies for detecting and quantifying added blood proteins in processed meat products.
A blind trial using beef and pork meat adulterated with bovine and porcine serum was undertaken to test the developed method. <P>
Results and findings:<BR>Species-specific monoclonal anti-albumin antibodies that reacted strongly with albumin in heated bovine and porcine blood serum were successfully generated. These antibodies were used to develop sensitive immuno-assays to monitor and quantify the presence of added bovine and porcine serum and plasma in processed meat products. Quantification of added serum was found to be good during a blind trial with estimated values closer to the actual when higher levels of serum were added (7-15%). The method showed some reduced efficacy in the presence of fillers, such as rusk or potato starch, which may be present in some processed meats, although this is improved in the presence of salt. A Standard Operating Procedure for this method has been produced.
<p>Find more about this project and other FSA food safety-related projects at the <a href="http://www.food.gov.uk/science/research/" target="_blank">Food Standards Agency Research webpage</a>.