Effect of heat treatment on hen’s egg ovomucoid: An immunochemical and calorimetric study

Egg causes a great number of allergies, being the allergenic proteins mainly contained in the white fraction. Among white proteins, ovomucoid is one of the most allergenic and can be considered as a good marker to detect egg in foods due to its high thermostability. We have studied the effect of heat treatment on ovomucoid immunoreactivity by ELISA and its denaturation in different media by differential scanning calorimetry (DSC). Ovomucoid was subjected to heat treatment in a range from 85 to 95 °C in buffer at pH 7.4. D values were obtained for the process of loss of immunoreactivity at the different temperatures and the Z value was of 15.6 °C. DSC of ovomucoid has been performed in two different buffers, at neutral or basic pH, and also in egg white. It has been found that ovomucoid is more thermoresistant at basic than at neutral pH. Furthermore, the resistance of ovomucoid in egg white is different to that observed in buffer at the same pH.