Kiwi allergy concern drives new test methods

UK food analysis firm RSSL has added kiwi fruit to the list ofallergens it can detect by PCR (polymerase chain reaction) methods.

The company claims that by using PCR, it can detect traces of kiwi fruit down to 10mg/ Kg (10ppm) levels.

The announcement is likely to be welcomed by food makers who use kiwi as a natural ingredient. The fruit is now considered as one of the most serious allergens not currently included on the labelling list of the European Directive 2003/89/EC, which is due to take full effect from November 25, 2005.

The directive means that manufacturers will have to list all sub-ingredients of compound ingredients, so that allergens cannot be 'hidden'. But kiwi fails to fall into the list of potential allergens, having seemingly slipped through the net when the proposals were first aired.

The fruit has not always been seen as a potential source of allergy. Kiwis were first introduced into the UK diet in the late 1960s, and consumption has increased steadily since then, with over 31,000 tonnes of the fruit imported into the UK alone in 2002.

According to researchers at Southampton University, very few allergies to kiwi fruit were reported in the 1970s but reactions were increasingly reported in the 1980s, predominantly in adults. It was not until the 1990s that the kiwi fruit allergy was more commonly reported in children and young infants.

Even at these low levels an allergic response in sensitive individuals can range from oral allergy syndrome (OAS) and urticaria (nettle-rash) through to dysphagia, nausea and vomiting. In a small percentage of highly sensitive individuals, it may cause severe life threatening anaphylaxis.

Dr Jane Lucas, a paediatrician and clinical research fellow at the University of Southampton explained to FoodNavigator.com earlier this year that his team of scientists are currently trying to understand why children and adults react differently to the fruit.

"We are currently undergoing trials in the laboratory to work out the impact of the kiwi proteins on adults and children. We have over 100 blood samples to analyse," said Dr. Lucas. This next phase is due for completion in 18 months time.

RSSL, which claims it can now analyse food and ingredient samples for a wide range of allergens, is holding a half-day seminar on the new directive 2003/89/EC andits implications for the food industry on 5 October in Reading, UK.

"There is still some confusion about what's going to be required," said Simon Flanagan, RSSL's allergen consultant. "The seminar will provide a timely reminder of the main points of the new regulations and will address the key clinical, regulatory and analytical issues."