**8. Immunodominant soybeanallergen P34**

Protein P34 (Gly m Bd 30K) is the immunodominant allergen in soybean. Among com‐ mercial soy ingredients, soy flour displayed the highest P34 antigenicity (32 mg/g ex‐ tracted protein) followed by soy protein isolate (29 mg/g extracted protein) and soy protein concentrate (24 mg/g extracted protein). Among soy consumer products, soymilk exhibited the highest P34 antigenicity (from 7 to 23 mg/g extracted protein), followed by tempeh (8 mg/g extracted protein), soy infant formula (3.4 mg/g extracted protein), soy powder (2 mg/g extracted protein), and soy cheese products (0.50 mg/g extracted pro‐ tein). Korean miso, soy sauce, soy chili mix, soy nuts, soy cream cheese, soy meat patty, texturized soy protein, and soy cereal exhibited undetectable P34 antigenicity (detection limit = 0.45 ng). Selecting soybean varieties low in this allergen, or via processing, poten‐ tially can render soybean products less antigenic [10].

The sera from 3 of 9 (33%) patients with outgrown soybean allergy and 6 of 9 (66%) patients with soybean allergy were classified as positive. Sodium dodecyl sulfate (SDS)-treated re‐ combinant P34 retained its structure and biological activity. Recombinant P34 is a useful tool for the analysis of antigen-specific response in soybean allergy. A modified form of recombi‐ nant P34 for the diagnosis or treatment of soybean allergy using specific immunotherapy techniques may be available in the future [11].
