There are 3 food allergens associated with turnip allergy.
Bra r 1 is a 2S albumin protein. These are seed storage proteins most commonly found in nuts and seeds.
Bra r 2 is prohevein protein which is used in the plant for defence.
Bra r 3 is a polcalcin protein. These are commonly called panallergens and are usually associated with airway allergens (pollens).
Turnips contain prohevein which is similar in shape to those of latex plants, which can cause those suffering from Latex Food Syndrome to have allergic reactions to turnips.
Other food containing 2S albumin seed storage proteins are cashews, peanuts, brazil nuts, mustard seed, rapeseed, pecans, chickpeas, hazelnuts, pistachio, buckwheat, soya, sunflower seeds, walnuts, kiwi, castor beans and sesame seeds.
Those with a sensitivity to hevein may have linked allergies to foods which contain high levels of chitinase, like banana, avocado, chestnuts, corn (maize), kiwi, papaya, pomegranate and tomatoes.