The Nature of Food Allergens and Testing for Their Presence
Certain substances, especially animal and plant proteins, have the ability to provoke adverse physiological reactions in some individuals. Such effects may arise when the offending substance is swallowed or inhaled, and even as a result of contact with the skin, depending upon its identity. Not everyone displays such reactions, and among those that do, they are usually sensitive to just one or two substances, unless their immune systems have been compromised by disease.
In some individuals, inhaling household dust is likely to provoke an asthma attack, whilst others may develop a skin rash after wearing clothes washed in a certain detergent. The substances that may provoke such reactions are known as allergens, and any that may be present in food need to be identified, so that consumers will be warned of the possible risk to their health. On occasions, an allergic reaction can be extreme, resulting in a condition known as anaphylactic shock, which is frequently fatal if not treated in time.
Many people find that thy must avoid consuming edibles such as nuts, casein and beta-lactoglobulin in dairy products, eggs, cereals, mustard, soy and shellfish, which when in their natural and recognisable forms, is quite easy. However, many of these same edibles are often present, yet hidden, in processed foodstuffs. They may either be included by design, as a means with which to provide flavour or some other desirable property, or as accidental contaminants introduced during the manufacturing process.
Even some inorganic substances, such as the sulphur dioxide gas commonly used to preserve dried fruits, can leave residues that can cause breathing difficulties, hives or other symptoms of allergy. Whatever the nature of these substances, or the explanation for their presence, manufacturers of processed food and beverages are now required to operate stringent allergen control programmes, in addition to their normal hygiene and quality testing. They must also ensure that all of their cartons, wrappers and/or cans that they use carry labels that clearly display the identity of all potentially allergenic substances found to be present, even if only in trace amounts.
The specific composition of these problem ingredients requires the use of equally specific test procedures. Furthermore, tests must accommodate both solids and liquid ingredients, and include not only finished products, but also surfaces in the production areas, and even the products used to clean them. Along with the testing of individual ingredients, the latter precautions are aimed at minimising the risk of accidental contaminants, whilst tests on finished products are to detect any trace amounts of these that could not be excluded.
Known internationally as an industry leader in food safety, Neogen has developed efficient test kits for the screening and quantitation of allergens, including peanuts, a wide range of specific tree nuts such as almonds, hazelnuts and walnuts, casein, gluten, crustaceans, and many more. The Neogen Reveal 3-D kits are strip tests, ideal for the screening of trace quantities, and provide results in 10 minutes or less. For quantitative purposes, the Veratox® kits can handle up to 19 samples at a time, and compare them with five test controls.
Neogen products and full support for them are available in South Africa from the nation’s preferred supplier of laboratory requisites and medical diagnostic for the best part of 40 years – IEPSA.