Allergen test for new food labels
processed foods that could help food makers adhere to the tough new
European rules on food allergens to be enforced later this year.
In November new food labels will have to list certain potentially allergic ingredients, including cereals containing gluten, fish, crustaceans, eggs, peanuts, soy, milk and dairy products, nuts, celery, mustard, sesame seed, and sulphites.
At present, exemptions to the requirements for ingredient listing on pre-packed foods mean that some ingredients, including those that may be allergenic, are not always indicated.
Scientists at Florida State University in the US subjected walnuts, cashew nuts and almonds to radiation, roasting, pressure cooking, blanching, frying and microwave heating in an effort to make them safe for allergy sufferers.
The nuts refused to surrender their allergens, but the research yielded sensitive techniques that detect minute traces of the nuts in seemingly nut-free processed foods.
The researchers had previously identified the specific tree nut proteins relevant to human allergies. They then aimed, through irradiation alone or in combination with other thermal treatments, to induce changes in the protein structures to reduce or eliminate allergenicity and antigenicity.
But the antigenicity of the tree nut proteins remained mostly unchanged throughout the irradiation and thermal processing, dashing hopes that the treatments would render the healthy snacks safer for wider consumption and more profitable for growers and industry.
However, the scientists led by Shridhar Sathe, report that there was a positive aspect to the findings - precisely because the irradiation and thermal procedures likely to be encountered during commercial processing did nothing to alter the tree nut protein antigenicity.
They claim that lab tests originally used on unprocessed cashew nuts, almonds and walnuts to detect antigenic proteins could now be reliably applied to detect minute traces in already-processed food products as well.
"Development of specific, robust, sensitive and reproducible assays for tree nut detection will help protect sensitive consumers who must rely on accurate labeling, as well as food industry and regulatory agencies who monitor the presence of trace quantities in both food and feed," said Sathe. He cautioned that "continued and vigorous research is now urgently warranted" to expedite preparation of the techniques for commercial use.
Improper food labelling and cross-contamination during commercial processing can pose serious threats to sensitive consumers and can often lead to expensive food recalls for the food maker. In a bid to reduce the risk, last November Europe confronted the food industry with new rules on food allergen ingredients. Directive 2003/89/EC, amending Directive 2000/13, means that manufacturers will have to list all sub-ingredients of compound ingredients, and so allergens cannot be 'hidden'.
The directive heralds an end to the 20-year-old '25 per cent' rule under which individual ingredients making up a compound ingredient do not have to be listed if the compound ingredient makes up less than 25 per cent of the finished product.
The new rules establish a list of 12 foods that will have to be listed clearly on labels whenever they are used in pre-packed foods, including alcoholic drinks. Labels will also need to give clear information about ingredients made from these foods, for example a glaze made from egg.