Decrease in Ovomucoid Antigenicity in the Processes of Breadmaking Supplemented with Egg White

The anitigenic activity of ovomucoid (OM) remaining in bread samples containing egg white was analyzed at several stages of bread making; dough preparation, kneading, fermentation and baking. Change in OM antigenicity at each stage was examined using competitive ELISA with rabbit anti-OM serum. OM antigenicity was remarkably reduced by baking but not by kneading and fermentation. The antigenicity completely disappeared in the breads baked at 150°C for 4 min or more, even though it substantially remained when egg white was heated alone under the same condition. OM in the baked bread samples was solubilized with SDS/2-ME-containing solution but not with the solution containing SDS alone, suggesting that baking with wheat flour induced irreversible denaturation of OM with a disulfide exchange reaction leading to the loss of its antigenic activity.