The incidence of people suffering violent reactions as a result of consuming food that contains allergens has been increasing in recent years. There have even been cases of people suffering fatal anaphylactic episodes while dining in restaurants. Though the reason for this increase remains unconfirmed, there is evidence that more individuals now seem to have a weakened immune system. While it may be advisable for those who are aware they are prone to allergies to carry an Epinephrine auto-injector, it is actually legally binding upon those responsible for supplying our edibles to ensure that their products carry a clearly visible warning of any ingredients that might provoke a life-threatening immune response.

Among the most common food allergens are eggs, milk, soy, shellfish, and nuts – and these are found in various processed foods. They may be present as basic ingredients of a product or they may be substances introduced in order to enhance its colour, flavour, or texture. On occasions, such substances may even occur as unavoidable contaminants of a basic ingredient as a result of its environment or handling. One thing, however, is quite certain. Those warning labels highlighting the presence of these substances are absolutely essential to the safety of susceptible consumers.

In order to abide by the strict labelling requirements now in place, manufacturers are, of course, obliged to subject batch samples to whatever tests may be necessary to either confirm or eliminate the presence of food allergens as part of a routine quality-control programme. Today, the demand for processed foods has reached an all-time high and it is therefore important to the producers that each batch of their product can be released to the market as soon as possible and not retained for prolonged periods whilst awaiting the results of time-consuming laboratory tests. At the same time, it is every bit as important that any quick testing procedures that may be introduced are able to provide results that are both accurate and consistent.

Analytical chemists have responded to this need with a range of test kits and instruments designed to reduce test times for detection and quantitation of allergens in food to an hour or so. In some cases, testing can take just minutes, while all benefit from the ability to handle multiple samples simultaneously. Test kits are available from a variety of manufacturers and most of their products rely on a technique known as enzyme-linked immunosorbent assay or ELISA.

These tests involve the use of specific antibodies to bind with the allergenic material or associated marker protein selectively. Once bound, the attached enzyme initiates a colour reaction in a substrate. The intensity of colour produced is measured electronically and is proportionate to the concentration of the allergenic material detected. Where ELISA tests may be less effective, testing may leverage a second technique known as the polymerase chain reaction of PCR, in which the DNA present in specific food allergens becomes the target for detection and quantitation using a fluorescent marker.

The importance of reliable screening tests for these potentially lethal substances cannot be overstated and there is no laboratory supplier in South Africa that understands this better or caters more fully to meet these needs with world-class products than IEPSA.

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