IMMUNOHISTOCHEMICAL TECHNIQUES APPLIED TO RAW AND MILDLY HEAT-TREATEDMEAT SYSTEMS

Immunohistology was performed with six commercially available antibodi es directed against myosins, actins and collagens. The corresponding a ntigens, appearing on the surface of cryo-sections from meat and meat products heat treated to different end temperatures, were visualized u sing these antibodies. The meat and meat products were heated from 20- degrees-C to 80-degrees-C. At 80-degrees-C the meat systems were devoi d of thermal transitions as judged from differential scanning calorime tric measurements. Our results showed that although reduced binding wa s the case for systems heated above 60-degrees-C, the signals from the antibody labelling was still sufficiently strong to provide informati on about specific antigens in meat systems heated to 70-80-degrees-C. Antibodies with a high initial affinity bound to the their respective antigens after the latter had been heated to a few degrees above their denaturation temperature as detected in a scanning calorimeter. This investigation points to the possibility of finding sufficiently good c ommercial antibodies to perform immunohistology on meat products heate d to temperatures between 70-80-degrees-C. This is important as many c ommercial meat products are heated to end temperatures in this range. Several examples of the labelling intensity obtained on heated meat an d meat products are given. In addition, an example using double labell ing with antibodies to collagen III and an antibody to slow myosin in a food product heated to 75-degrees-C is given. Problems related to no n-specific staining and to non-specific effects of heat treatment are also briefly discussed.