Soybean Oil & Lecithin: Are They Allergenic?
The Food Allergen Labeling & Consumer Protection Act (FALCPA) in the U.S. mandates labeling of all ingredients derived from commonly allergenic foods, including soybeans, with the exception of highly refined oils. Commercially, soybean oil and soy lecithin are two of the most important food ingredients. Are all soybean oils excluded from labeling? Why? What about soy lecithin?
Highly Refined Soybean Oil Most soybean oil manufactured in the United States and added to food products is highly refined. FALCPA exempts highly refined oils from the new source labeling provisions because highly refined soybean, peanut and sunflower seed oils have been clinically documented to be safe for consumption by individuals allergic to the source food.1-5 Commercially, the soybean oil refining process uses extraction with hot solvents, bleaching and deodorization, and these processes serve to eliminate almost all soy protein, and thus allergens, from the oil.6 Although highly refined soybean oil contains extremely low levels of detectable soy protein, FALCPA provides an exemption from source labeling.
Cold-Pressed Soybean Oil Cold-pressed, also known as extruder-pressed, soybean oil is not excluded from source labeling. This type of soybean oil is often found in natural food sections or gourmet sections of retail stores, and typically is not used as an ingredient in further processed foods. Although cold-pressed soybean oil has not been documented to provoke allergic reactions, this type of oil is likely to contain somewhat higher levels of residual protein than highly refined oil. The safety of cold-pressed soybean oil has not been documented by clinical challenge trials beyond one small trial in seven soy-allergic subjects.3
FALCPA also requires the labeling of soy lecithin because it is derived from soybeans and contains residual protein. The Grocery Manufacturers of America and other trade associations are working with the Food & Drug Administration to try to exempt soy lecithin from the source labeling requirement of FALCPA. Soy lecithin is acknowledged to contain residual levels of protein, although the amount of residual protein is uncertain. The Food Chemicals Codex specification for lecithin allows a maximum of 0.3 percent hexane insoluble matter in food-grade lecithin. If all protein, then the upper limit for protein should be 3,000 ppm. No validated method is available for the precise measurement of protein levels in lecithin. Soy allergens have been identified within the residual protein in soy lecithin by various investigators. However, the presence of residual levels of soy protein and soy allergens in soy lecithin is insufficient to document the allergenicity of soy lecithin. Only two reports exist of allergic reactions to soy lecithin among soy-allergic consumers, despite its widespread use.7, 8 The allergenicity of soy lecithin remains unknown, although the very small number of documented episodes and their questionable nature suggest empirically that its allergenicity is quite low.
Editor’s Note: This work is a contribution from the University of Nebraska Cooperative Extension Division, Lincoln, Nebraska, Journal Series No. 1033.
REFERENCES1) Taylor SL, Nordlee JA, Vadas P, et al. Food Chem Toxicol 2006 (submitted).
2) Hourihane JO’B, Bedwani SJ, Dean TP, Warner JO. Br Med J 1997; 314:1084-1088.
3) Bush RK, Taylor SL, Nordlee JA, Busse WW. J Allergy Clin Immunol 1985; 76:242-245.
4) TaylorSL,BusseWW,Sachs MI, etal.JAllergyClinImmunol1981; 68:372-375. T aylor SL, Busse WW, et al. J AllergyClinImmunol1J Aller gy Clin Immunol 1981;
5) Halsey AB, Martin ME, Ruff ME, et al. J Allergy Clin Immunol 1986; 78:408-410.
6) Crevel RWR, Kerkhoff MAT, Koning MMG. Food Chem Toxicol 2000; 38:385-393.
7) Palm M, Moneret-VautrinDA,KannyG,etal.Allergy1999; 54:1116-1117. Palm Moner et-Vautrin DA, Kanny G, et al. Allergy 1999; 8) Renaud C, Cardiet C, Dupont C. J Pediatr Gastroenterol. Nutr. 1996; 22:328-329.