Mal d 1 is similar to the protein found in birch pollen, a common cause for allergy. A substantial part of the population in Northern Europe suffers from birch pollen allergy, and most of them also show reactions towards certain plant-derived food, such as apples, strawberries, carrots, celery and nuts.
In Sweden, up to 90 per cent of birch pollen allergic patients are sensitised to apples, with symptoms like itching and swelling of lips, tongue and throat after ingestion. In total, an estimated 4 per cent of adults and 8 per cent of children in the EU suffer from food allergies, according to the European Federation of Allergy and Airways Diseases Patients' Associations.
The success of the department of crop science at SLU in Balsgård, Southern Sweden, in developing an allergen-free apple, will obviously be of great interest to the growing allergen-free food and beverage market. It also comes just as scientists at the UK-based Institute of Food Research discovered exactly how the Mal d 1 allergy protein retains its potency during processing.
This is based partly on economics. The number of children who have food allergies has quadrupled over the last few decades, with the Journal of Allergy and Clinical Immunology reports that the number of children allergic to peanuts for example increased two-fold over a single five-year period from 1997 to 2002.
A growing awareness of the problem among the general public, along with high-profile media coverage, has created an active and growing market for free-from products.
But both industry and consumers will have to wait a while for the allergen-free apple. The product is not due to hit the market for another four to five years.
"First it must be investigated where the best conditions for growing the new apple can be found," said professor Hilde Nybom, head of research at the Balsgård-based facility.
"The market for the new apple will also be investigated."
Previous studies have shown that commonly used apple cultivars like Granny Smith, Golden Delicious and Cox Orange are highly allergenic, i.e. contain high levels of Mal d 1, whereas some local cultivars like Gloster, Jamba and Belle de Boskoop appear to be low-allergenic.
New legislation brought into the EU at the end of 2004 and to be enforced in November this year imposes considerable legal requirements to curb the risk for food allergy sufferers.
Directive 2003/89/EC, amending Directive 2000/13, essentially means food makers must flag up on the food label possible allergen ingredients and their derivatives: cereals containing gluten, fish, crustaceans, egg, peanut, soy, milk and dairy products including lactose, nuts, celery, mustard, sesame seed, and sulphites.
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