There are particular foods and fruits that are known to produce a type of substance that is similar to the rubber latex. This is known as the latex-fruit syndrome. Fruits (and seeds) involved in this syndrome include banana, pineapple, avocado, chestnut, kiwi fruit, mango, passionfruit, strawberry, and soy, as well as potato and bell pepper.
S Wagner, H Breiteneder The latex-fruit syndrome. Biochem. Soc. Trans.: 2002, 30(Pt 6);935-40