Managing allergens through cleaning

ALLERGEN MANAGEMENT through cleaning in the food, dairy, beverage and brewing industries is an essential control to reduce the risks to vulnerable consumers through the unintended cross-contact of allergenic proteins into other products.

What is an allergen?

An allergen is a substance that can cause an allergic reaction. In some people, the immune system recognizes allergens as foreign or dangerous. As a result, the immune system reacts by making a type of antibody called IgE to defend against the allergen. This reaction leads to allergy symptoms and can in some cases be deadly.

Common allergens relevant to food and beverage include egg, peanut, milk, nuts, soy, wheat (Gluten) and fish amongst others.

To ensure against cross-contamination, those operatives undertaking cleaning activities following production of an allergen containing product, must be aware of the vital role they play in preventing the cross-contact of allergenic proteins into subsequent batches or items and that it is not just cleaning for cleaning’s sake.  This involved the correct training.

The need for training and awareness and its importance cannot be overemphasised.  Those engaged in cleaning activities following production of an allergen-containing product must be aware of the vital role they play.  The key message it that contamination is unlikely to be homologous as the early part of the run would contain potentially higher levels of extraneous protein simply because it would pick up the debris on passing.

Hygiene operatives should clearly understand as part of their training that:

1. Chemicals do not inactivate or ‘kill’ allergens
2. Disinfectant has no material effect on allergenic proteins
3. The potential consequences of cross-contact allergens reaching a vulnerable consumer
4. The prevalence of both allergic and intolerant reactions in the population.

Supervisors and managers should take more advanced and detailed allergen training to appreciate the science behind the subject and the role that cleaning plays in their organisation’s overall food safety strategy.

There are three main steps to implement in any cleaning regime:

1. Cleaning procedures – adoption of processes that fit your business
2. Control – implementing adequate cleaning procedures to prevent risk
3. Verification – validating the results of the cleaning and its effectiveness.

Regardless of the type of food business, cleaning generally falls into four types:

1. Dry cleaning
2. Deep cleaning
3. Inter-product ‘changeover’ cleans
4. Automated cleaning.

One of the first considerations is the type of surfaces to be cleaned and the ‘cleanability’ of those surfaces. Stainless steel is the easiest of surfaces to clean with cloth and wood being the most difficult to remove allergen residue from, mainly due to the porosity of the surfaces.

The ‘cleanability’, combined with the surface material’s reaction to certain chemical types, will determine the most successful cleaning regime to use.

Dry cleaning

This method is often employed where water sprays can’t be used, in a bakery for example. In this scenario, the first step would be to use scrapers or brushes to remove the gross debris followed by the application of a detergent in a controlled manner. This should ensure effective removal of any allergenic ingredients.  Disinfectant, if applied, is usually alcohol-based which evaporates to leave a microbiologically clean surface with no moisture.

Deep clean

This type of clean is carried out over a longer time period and often at night, it includes several steps:

• Pre-rinse to remove gross debris
• Application of a detergent
• Manual agitation of the detergent
• Prolonged rinsing
• Application of a disinfectant
• Possible final rinse depending on product used.

This regime may use chlorinated or highly alkaline detergents, which together with physical agitation from a brush, green pad of pressurised water jet, will remove food debris ensuring the allergenic residue is also removed.

Inter Product Cleans

Also referred to as Change-over cleans, this is where problems and potential risks in the removal of allergens are most likely to occur.  A product change clean is often less effective than a hygiene clean for a number of reasons.

Staff are often lacking in awareness and training in the correct method of cleaning equipment, plus a lack of motivation.  The use of less aggressive, often neutral, chemicals leads to a poorer removal of residues and add to this the pressure of Production Management needing to reduce down-time to a minimum.

Automated cleans

This involves any clean where the mechanical energy of the clean is supplied by automatic means.  For example, in a tray-wash unit or CIP where jets and detergent streams are used.

The common concern here is carry-over of allergenic residue from one product cleaning cycle to another but if the cleaning cycle is operated correctly and has been validated, then the risks are reduced.

It goes without saying that the tools and equipment used during allergen cleaning must themselves be cleaned to avoid them becoming sources of debris.  Usually, specific colour-coded utensils are used for cleaning post-allergens and these must be hygienically designed, capable of being effectively cleaned and stored safety between use.

And finally, an effective clean involves visual checks from line supervisors. Obvious ‘trap areas’ need to be identified and checked before restarting production.  A rapid checking system, specifically for allergens also helps ensure the validity of the clean and that all due diligence has been carried out.

Checking the quality of the clean

In order to ensure allergen control through cleaning processes, it is necessary to undertake validation of all cleans using test techniques.  These need to be repeated on a routine basis, the frequency of which will be determined by the company’s HACCP and risk assessment process and by customer-led demands.  Cleaning verification also proves consistency in cleaning.

Validation of the hygiene regime is critical in determining practices, equipment and chemicals are fit for purpose in delivering a safe food production environment.

Allergen validation is undertaken using ELISA (Enzyme Linked Immunosorbent Assay) which can provide very specific analysis of the allergenic protein present as well as providing quantification information. This analysis is undertaken in dedicated equipment often against standards which contain known levels of the allergenic protein of concern, thereby providing quantification of the level of allergenic protein present in the sample.

DNA analysis can also be used for identifying allergens, however care should be taken as the analysis can only assess the presence of DNA and not distinguish between the type of protein. As an example, DNA analysis cannot distinguish between milk proteins and the presence of beef; or the use of chicken meat and the presence of egg protein.

Since the introduction of allergen labelling legislation in 2004, the pre-packed food industry has become experienced in managing allergy cross-contract including verification of cleaning activities.  Although allergen recalls continue, most involve incorrect packaging or labelling errors rathe rather than hygiene controls.

To undertake verification testing for allergen presence or absence the only available technology is that based on antibody assessment using either specific lateral flow or flow-through tests.  These tests are currently the best available technology for real-time rapid testing and although there are limitations, they do provide surety that allergen cross-contact is controlled.  Results are available in under ten minutes.

ATP testing has, for many years, been utilised as a non-specific hygiene monitoring tool whereby the level of organic debris present on a surface can be readily assessed utilising a biochemical mechanism that highlights the debris.

As ATP is present in all living cells whatever the source, this technology’s use as a non-specific tool is well placed, however when considering allergen management care must be exercised. This is because vulnerable consumers react to the allergenic proteins present in the food matrix and not the organic matter. 

Protein is a cellular component and does not contain any ATP and circumstances often occur where the level of organic debris is low, but there is significant contamination with allergenic proteins which could represent a hazard to consumers. For this reason, care must be exercised when considering ATP assessment as a method for verifying that a clean involving allergenic protein has been successful.

As a rule of thumb, if there is significant organic debris present then it is highly likely that allergenic protein remains, however the reverse is not always the case. For this reason, users are advised not to rely on ATP assessment alone for verifying cleaning standards where allergens are involved.

In conclusion, choosing the right chemical and enzyme-based products for the type of surface and following this with a well-designed and executed hygiene validation and verification regime will give the food producer peace of mind and a high degree of control over the safe and hygienic manufacture of its products.  In the end, allergen management is all about the standard of cleaning.

Peter Littleton is UK technical director at Christeyns Food Hygiene. An expert in his field, Peter is also training services & events director for the Society of Food Hygiene and Technology (SOFHT). He supported the society’s “Allergens: getting it right first time, every time” on September 20^th at Drayton Manor Hotel.

For more information visit​ www.christeyns.com