Immunohistochemical Techniques Applied to Raw and Mildly Heat Treated Meat Systems

Immunohistology was performed with six commercially available antibodies directed against myosins, actins and collagens. The corresponding antigens, appearing on the surface of cryo-sections from meat and meat products heat treated to different end temperatures, were visualized using these antibodies. The meat and meat products were heated from 20 °C to 80 °C. At 80 °C the meat systems were devoid of thermal transitions as judged from differential scanning calorimetric measurements. Our results showed that although reduced binding was the case for systems heated above 60 °C, the signals from the antibody labelling was still sufficiently strong to provide information about specific antigens in meat systems heated to 70-80 °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 fmding sufficiently good commercial antibodies to perform immunohistology on meat products heated to temperatures between 70-80 °C. This is important as many commercial meat products are heated to end temperatures in this range. Several examples of the labelling intensity obtained on heated meat and meat products are given. In addition, an example using double labelling with antibodies to collagen III and an antibody to slow myosin in a food product heated to 75 °C is given. Problems related to non-specific staining and to non-specific effects of heat treatment are also briefly discussed