54I-4

S. L. HEFLE, D. Lambrecht, and J. A. Nordlee. Food Allergy Research and Resource Program, Univ. of Nebraska, 255 Food Industry Building, Lincoln, NE 68583-0919

Soy allergy is one of the most prominent allergies in the worldwide population. The vast majority of soy sauces are produced through the fermentation of soy and wheat. Some soy sauce manufacturers tell finished food product processors (and also soy- and wheat-allergic patients who contact them) that the fermentation process destroys the allergenicity of their soy and wheat fermentation ingredients. This has not been proven to be the case by scientific experimentation, so the risk of reaction from soy sauce ingestion among soy-allergic and wheat-allergic/celiac patients is unknown. This test sought to evaluate several types of soy sauce for residual protein and also residual allergenic activity. Ten soy sauces were evaluated using three soy-specific animal IgG-based ELISAS (two of which are commercially available), by soy polymerase chain reaction (PCR) analysis, and also by RAST inhibition using sera from soy-allergic subjects. The soy IgG-based ELISA tests and PCR tests showed no detectable residues of soy protein or soy DNA in the ten sauces. However, in RAST inhibition (using soy flour as the solid phase), some soy sauces contained 10 to 30% residual activity. Soy sauces made by fermentation of soy protein can retain some of their soy allergenicity (10 to 30% that of soy flour) through the fermentation/production process. It is significant that soy IgG-ELISA and PCR analyses do not detect the remaining allergenic residues in soy sauce. Therefore, results from these types of ELISA and PCR tests should not be used by soy sauce suppliers nor finished food manufacturers to indicate that soy sauce is devoid of allergenic residues and safe for soy-allergic individuals to consume. Soy-allergic patients should continue to be counseled to avoid soy sauce.

Session 54I, Toxicology & Safety Evaluation: General
2:00 PM - 5:30 PM, Monday PM Room Hall I-2

2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana