Best practices for allergen testing

While virtually unknown before the 1950s, food allergies have emerged as one of the most serious and prevalent public health issues in the developed world. It is now essential that food processors can identify and control allergens where there is potential for cross-contact as part of their risk management program.

According to the Allergen Bureau, food allergens are typically naturally occurring proteins in foods or derivatives of them that cause abnormal immune responses. The prevalence of food allergies around the world is believed to be increasing, with more than 8% of children and 2% of adults in countries like Australia and New Zealand having an allergy to one or more foods. The most common allergens for young children are milk and egg, but fortunately many children outgrow these allergies by the time they have reached 5–7 years of age. On the other hand, allergies such as those to seafood, peanut and tree nut may develop later and are lifelong conditions.

Allergic reactions to foods vary greatly from mild gastrointestinal discomfort to skin rashes and potentially life-threatening asthma and anaphylaxis. Commonly, many adverse reactions to food are collectively referred to as food allergies. However, true food allergies represent only a fraction of the diverse range of individualistic adverse reactions to ingredients that also include food intolerances. Examples of common food intolerances include coeliac disease (reaction to gluten) or deficiencies in the digestive system (eg, lactose intolerance).

Currently, there is no cure for food allergies. The only successful method to manage a food allergy is avoidance of foods containing the allergen.

Potentially, all foods have the capacity to cause an allergic reaction in a person who has become sensitised to proteins in it. However, in Australia and New Zealand there are nine foods or food groups that cause about 90% of all allergic reactions:

• Peanuts
• Tree nuts such as almonds, walnuts and cashews
• Soy
• Milk including cheese, butter and milk powder
• Eggs
• Cereals including rye, oats and barley
• Crustaceans such as crabs and prawns
• Fish
• Sesame

These foods have been documented within the Food Standards Code. Warning statements must appear if the food or an ingredient derived from the above contains the allergen.

It can be incredibly difficult to shop or dine out with a person who has a food allergy. More so, with the plethora of confusing cautionary statements such as ‘may contain’, ‘may be present’, ‘made on equipment that is also used to make’ etc.

The challenge for the food industry is to identify and control allergens where there is potential for cross-contact as part of a risk management program. This is especially the case where there is an unintentional transfer of allergens from ingredients or the products where they are manufactured, moved, transported or stored using common equipment, people and facilities.

As such, the food industry bears a significant due diligence to not only ensure allergen warnings are clearly spelled out on packaging but their food products are not exposed to inadvertent contamination from potential allergens.

Your essential tool for allergen control

Ideally, the best control for food allergens is to not bring them into the workplace. For example, a dip manufacturer might only make a range of dairy- and gluten-free products at the site. However, this is often not viable as many food businesses need to be competitive and are required to make a wider range of products. An example of this is where a bakery produces a macadamia nut cookie for a unique customer once per week. Where there are non-shared allergens that are only used in a smaller range of products on-site, they are often controlled via a number of overlapping practices. These can include:

• Ingredient supplier management
• Production scheduling
• Cleaning
• Colour coding
• Dedicated processing equipment
• The unique storage of ingredients
• Staff training
• Defined movement paths within the workplace

Although the above practices may be in place, appear to be working well and have been verified by visual monitoring, often a question is raised as to how effective they are. Verification by testing after cleaning provides a greater degree of confidence that this step is being performed correctly.

Today a variety of advanced methods exist to test for or indicate the presence and concentration of allergen-causing food proteins. These include enzyme-linked immunosorbent assays (ELISAs) for specific allergen residues, ATP detection, general protein detection and polymerase chain reaction (PCR) to detect DNA fragments from the allergenic food.

One key step within an effective allergen management program is the rapid and efficient detection of allergen protein residues from visually clean surfaces. In one case study the FDA found that protein tests are the most sensitive predictor of allergenic residues on surfaces compared to ELISA and ATP methods.

Simple and easy-to-use protein sensitive swab tests offer one of the most effective and efficient means to determine the presence of proteins including allergenic proteins from egg, milk, gluten, soy and peanut. The swab is rolled over the surface, then activated followed by a quick incubation. This test can be easily performed by proficient food production staff.

This highly sensitive protein detection technology allows for a broad range of potential allergens to be tested in a single swab with results displayed soon after testing.

The high degree of accuracy makes protein swab tests one of the most reliable weapons in your Allergen Management Plan arsenal.

Swab tests to detect allergen residues

Checking for removal of protein residues after cleaning can quickly identify contamination. As the majority of allergens are proteins, it indicates low risk of allergens being present if a surface is found to be virtually protein-free.

3M Clean-Trace Surface Protein (Allergen) is a simple and very sensitive swab test for the detection of protein residues on surfaces and in solution. It has been validated for a range of allergenic proteins, including egg, milk, gluten, soy and peanut.

If you are interested in finding more about this product visit www.3M.com.au/foodsafety (in Australia), www.3M.co.nz/foodsafety (in New Zealand), email 3mmicrobiologyau@mmm.com or call 130 363 878 (Australia) or 0800 326 886 (New Zealand).