Atsuo Urisu

The freeze-dried sample of heated and ovomucoid (OM)-depleted egg white previously developed by us was proved to be significantly hypoallergenic by oral challenge tests in double-blinded manner.<br>It was, however, difficult to be a substitution for egg white as food staff because of poor effervescency and solubility, and bad taste. Then, we have developed a simple and easy method to decrease OM content in heated egg white even at home. The OM amount in the sample proved to be effectively decreased by SDS-PAGE as compared to heated egg white. Next, we examined the allergenicity of the heated and OM-depleted egg white by double-blind, placebo-controlled food challenge using a rice dumpling containing this sample or heated egg white as positive control. A rice dumpling without egg white was used as placebo. All the subjects with positive resultes to the challenge tests with heat-treated egg white showed negative results for this sample. There was no significant decrease in protein content as compared to the heated egg white. In conclusion, the heated and OM-depleted egg white, which is able to be simpl made at home, is hypoallergenic enough to be eatable for egg-allergic patients.

The freeze-dried sample of heated and ovomucoid (OM)-depleted egg white previously developed by us was proved to be significantly hypoallergenic by oral challenge tests in double-blinded manner.<br>It was, however, difficult to be a substitution for egg white as food staff because of poor effervescency and solubility, and bad taste. Then, we have developed a simple and easy method to decrease OM content in heated egg white even at home. The OM amount in the sample proved to be effectively decreased by SDS-PAGE as compared to heated egg white. Next, we examined the allergenicity of the heated and OM-depleted egg white by double-blind, placebo-controlled food challenge using a rice dumpling containing this sample or heated egg white as positive control. A rice dumpling without egg white was used as placebo. All the subjects with positive resultes to the challenge tests with heat-treated egg white showed negative results for this sample. There was no significant decrease in protein content as compared to the heated egg white. In conclusion, the heated and OM-depleted egg white, which is able to be simpl made at home, is hypoallergenic enough to be eatable for egg-allergic patients.

There have been few reports on allergens in tomato fruit, one of foods causing oral allergy syndrome. We examined the major allergens by immunoblotting methods using 25 patients' sera with high IgE antibody titers for tomato fruit. Of these patients, 14 patients showed OAS after eating tomato. Approximately 15 protein bands were reactive to IgE antibodies from the patients. Five bands showed IgE-binding activity with more than 50% of the subjects. These proteins were deduced polygalacturonase 2A (46kDa), β-fructofuranosidase (25kDa and 22kDa), superoxide dismutase (18kDa), pectinesterase (14kDa) by homology search based on N-terminal amino acid sequences. These, except superoxide dismutase, may be proteins related with ripening because they were increased with maturation of tomato fruit.