Soy is one of the “Big 8” allergens in the US, while also being widely used in the food industry, in particular as texturizer, emulsifier and protein filler.
Many non-food products, including personal care products, pet food, adhesives and lubricants can also contain Soy. For instance, Soy lecithin can be present in pharmaceuticals and cosmetics. Soy is also common ingredient in infant formulas. With such widespread use, avoiding soy – whether directly or from risk of cross contamination – takes planning and dedication. This is as true for quality control professionals maintaining soy-free lines as it is for people who are themselves allergic to soy protein.
Ingredient labeling for Soy
Considering how ubiquitous soy is as an ingredient, and the many techniques for processing and use, special care must be taken when labeling. The FDA makes the following recommendations:
Contains soy:
- Bean curd
- Edamame (soybeans in pods)
- Hydrolyzed soy protein
- Kinnoko flour
- Kyodofu (freeze dried tofu)
- Miso
- Natto
- Okara (soy pulp)
- Shoyu sauce
- Soy albumin
- Soy bran
- Soy concentrate
- Soy fiber
- Soy flour
- Soy formula
- Soy grits
- Soy milk
- Soy nuts
- Soy nut butter
- Soy protein
- soy protein concentrate
- soy protein isolate
- Soy sauce
- Soy sprouts
- Soya
- Soya Flour
- Soybeans
- Soybean granules
- Soybean curd
- Soybean flour
- Soy lecithin*
- Soybean paste
- Supro
- Tamari
- Tempeh
- Teriyaki sauce
- Tofu
- Yakidofu
May contain soy:
- Artificial flavoring
- Asian foods (e.g. Japanese, Chinese, Thai, etc.)
- Hydrolyzed plant protein
- Hydrolyzed vegetable protein (HVP)
- Natural flavoring
- Vegetable brothVegetable gum
- Vegetable starch
Should be safe:
- Soy oil
- Vegetable oil delivered from soy
- Many doctors advise that most soy-allergic people can tolerate small amounts of soy lecithin, but it must still be labeled as soy on packaging.
What is the root cause of a soy allergy?
Allergy to soy is caused by storage proteins in the seeds. Two storage proteins have been identified as key allergens: vicilin and legumin. Storage proteins are generally stable heat-resistant proteins. Since high heat leaves these allergens largely intact, most forms of processing won’t render it non-allergenic: you can’t steam, boil, or burn away the part of soy that causes the reaction.
Who is affected?
Typically, allergic reactions first appear in infants and children under 3, and most of them outgrow the allergy by age 10. To date, no major studies have been conducted on the prevalence of Soy Allergy.
Unlike other food allergies, cross-reactivity is rare for Soy. Most individuals that are Soy allergic are tolerant of peanut as well as peas. This doesn’t mean that nobody has cross reactive issues; it still pays to be cautious. As a side note, there is some evidence that suggests the there is a link between Soy allergy and Hay Fever associated with Birch Pollen.
What are some foods where Soy can be an ingredient?
Soy and soy products can appear in many ingredients. An ingredient supplier should be able to include allergen information on its packaging. Following is a list of foods that may have soy used as an ingredient.
- Canned broth and soup
- Canned tuna and meat
- Cereals
- High-protein energy bars and snacks
- Infant formula
- Low-fat peanut butter
- Processed meats, like deli meats
- Soy-based milk, yogurt, ice cream, or cheese
- Textured vegetable protein (TVP)
- Worcestershire sauce
Soy incognito!
Soy can sneak into an ingredient under a different name! Watch for these aliases:
- Glycine max
- Hydrolyzed vegetable protein (HVP)
- Mono-diglyceride
- Monosodium glutamate (MSG)
Did you know?
- The FDA exempts highly refined soybean oil from being labeled as an allergen. Studies show most individuals with a soy allergy can safely eat soy oil that has been highly refined (not cold-pressed, expeller-pressed or extruded soybean oil). If you are allergic to soy, ask your doctor whether or not you should avoid soy oil.
- The federal Food Allergen Labeling and Consumer Protection Act (FALCPA) requires that all packaged food products sold in the U.S. that contain soy as an ingredient must list the word “Soy” on the label.
What are typical symptoms?
A soy allergy will rarely cause anaphylaxis, a potentially life-threatening reaction that impairs breathing, causes a sudden drop in blood pressure and can send the body into shock. General symptoms from an allergic reaction to Soy include;
- Itching in the mouth
- Rash or hives (urticaria)
- Nausea, vomiting or diarrhea
- Stuffy or runny nose
- Wheezing or other asthma symptoms
AlerTox Sticks Soy
AlerTox Sticks kits are specially designed to help food manufacturers monitor levels of common allergenic proteins at every step of production and in a variety of matrices. As with all of our tests, the kits are easy to use, accurate, and robust.
AlerTox Sticks Soy senses the presence of trypsin inhibitor from soybeans (STI) with a sensitivity of 100 ng / g (0.1 ppm). This inhibitor is denatured only in presence of high temperatures. There is no process to remove 100% of STI, although UHT processes significantly reduce the amounts of STI, making it undetectable to the kit.
Learn More About Soy Allergy
- Soy Allergy on the F.A.R.E. site
- Cross Reactivity between Soy Allergy and Birch Pollen
- Soybean Allergy information on InformAll
- Register on Allergence for reporting and recalls of foods containing undeclared allergens.
