Food Contamination and Prevention - III

Food Allergies

Food allergies are an increasing problem for the food industry including caterers. Food allergens cause the body's immune system to react, often within minutes but sometimes within hours. In serious cases a person may have an anaphylactic shock, which is life threatening. Even minute amounts of the allergen can result in serious problems. Peanut and other nut allergies are often very severe. Food allergy occurs when a person’s immune system reacts inappropriately to a food. The first stage of the process is called sensitization – when the immune system’s “memory” registers the food as a threat. Antibodies to that food are produced, and at a subsequent encounter, these antibodies connect with the food’s proteins and trigger the release of certain substances in the body, such as histamine. This results in an allergic reaction.

Symptoms

The first exposure to a specific allergen does not produce symptoms, however subsequent exposure result in an allergic response. Symptoms usually include some of the following;

Generalized flushing of the skin,
Nettle rash,

Swelling of the throat and mouth

Difficulty in swallowing or speaking

Severe asthma

Abdominal pain, nausea and/or vomiting

Sudden feeling of weakness (fall in blood pressure)

Collapse and unconsciousness

Food intolerances are usually less severe and do not involve the immune system. They may be due to a lack of enzymes or a response to an irritant.

Common Allergenic Foods

Foods which commonly contain allergens include:

Peanuts – also called ground nuts, are found in many foods, including sauces, cakes and desserts, Indonesian, Thai, Indian, Bangladeshi dishes and peanut flour and groundnut oil.

Nuts – these include walnuts, hazelnuts, Brazil nuts, cashew, pecan, pistachio, macadamia, Queensland nuts and almonds. Found in sauces, desserts, crackers, bread, ice cream, oil and marzipan.

Milk – including lactose, in liquid or powder form, in your yoghurt, cream, cheese butter and other milk products, ready to made or glaze dishes contain milk powder.

Eggs – found in mayonnaise, cakes, mousses, pasta, sauces and quiche. Sometimes use to bind meat in burgers, or to provide a glaze.

Fish – e.g. anchovies used in salad dressings, sauces, relishes, and on pizzas.

Shellfish – including prawns, scampi, mussels, lobsters and crab. Shrimp paste and oyster sauce are found in Thai and Chinese dishes.

Soya – may be found as tofu, bean curd, soya flour, and textured soya protein. Also found in ice cream, sauces, desserts, meat products and vegetarian products, e.g. veggie burgers. 

Cereals containing gluten – coeliac need to avoid wheat, rye, and barley, oats, splat and kaput and foods made from these. Bread, pasta, cakes, pastry, and meat product may contain wheat flour. Soups and sauces, dusted, battered, or bread crumbed foods may contain flour.

Sesame seeds – used in bread and breadsticks, Sesame paste (Tahini) in Greek or Turkish dishes, including hummus. Sesame seed oil used in cooking or salad dressings.

Mustard
Celery and celeriac

Some fruits such as strawberries and kiwi fruit and luptin flour can cause problems, in addition to colourants, artificial flavourings, and preservatives such as sulphur dioxide and sulphites all pose a risk to allergy sufferers.

Control of Allergenic Hazards

Manufacturers must exercise particular care during food production to ensure allergens do not contaminate other products, for example, dust from nuts does not end up contaminating a product that normally does not contain nuts. Cleaning to remove all traces of contamination can be quite difficult and therefore many factories use completely separate production lines or even different factories. Dust can be spread through ventilation systems or involve cross contamination from cloths, cleaning equipment or personal.

Food businesses should implement an allergen control system based on HACCP and prerequisite programmes to reduce risk from allergens. This will involve using reputable suppliers and branded goods, with all ingredients and foods clearly labeled; satisfactory packaging and segregated storage; using specific equipment for preparation, cooking etc.; segregated displays; separate serving utensils and clear labeling. Ingredient information must be available for all products and staff should know how to check this. In the event of a product becoming contaminated with an allergen it must be discarded or dealt with as a contaminated product.

If there is any risk of a product containing an allergen, it must be clearly labeled. Requirements for labeling allergens are defined in the food labeling regulations of each country (e.g. No 02, amendment, Regulations 2004, England). Foods which are identified as most likely to be allergen, it must be clearly labeled at all times.

In catering, effective communication and knowledge of all ingredients are essential to reduce the risk from allergens. Don’t guess, clear menu descriptions identifying potential allergenic ingredients should be provided, e.g. cooked in ground nut oil. Always update the menu when ingredients or recipes are changed. Staff must be instructed and trained about allergens and the implementation of effective control measures are working.

When a customer confirms they are allergic to a particular food, the person taking the order must provide accurate information to the person preparing the food. It is not just the menu item that may contain the allergen, it could be sauce used to make a garnish, it may be the oil used to cook the food or the allergen may be introduce because of a failure to effectively wash the hands or clean preparation equipment. Allergens won't usually be destroyed by cooking.

All staff should be aware of the action to take in the event of a customer having an anaphylaxis (severe allergic reaction as a result of a susceptible person eating a food containing an allergen).

(The customer may have a pre-loaded adrenaline injection kit which they use as soon as a serious reaction is suspected.)

The customer should not be moved and an ambulance with paramedic should be called using the emergency number. You should explain that the customer could have anaphylaxis.

What is Anaphylaxis?

Anaphylaxis (pronounced ana-fill-ax-is) is a severe and potentially life-threatening allergic reaction characteristically affecting more than one body system such as the airways, heart, circulation, gut and skin. Symptoms can start within seconds or minutes of exposure to the food or substance you are allergic to and usually will progress rapidly. On rare occasions there may be a delay in the onset of a few hours. Sometimes you will hear anaphylaxis referred to as an ‘anaphylactic reaction’.

An anaphylaxis is any allergic reaction, including the most extreme form, anaphylactic shock, occurs because the body’s immune system reacts inappropriately in response to the presence of a substance that it wrongly perceives as a threat. Thus symptoms are caused by the sudden release of chemical substances, including histamine, from cells in the blood and tissues where they are stored. The release is triggered by the interaction between an allergic antibody called Immunoglobulin E (IgE) and the substance (allergen) causing the anaphylactic reaction. This mechanism is so sensitive that minute quantities of the allergen can cause a reaction. The released chemicals act on blood vessels to cause swelling. In people with asthma, the effect is mainly on the lungs. There may also be a fall in blood pressure. If a patient has suffered a bad allergic reaction in the past, whatever the cause, then any future reaction is also likely to be severe. If a significant reaction to a tiny dose occurs, or a reaction has occurred on skin contact, this might also be a sign that a larger dose may trigger a severe reaction. It is particularly important that those with asthma as well as allergies are seen by an allergy specialist because asthma can put a patient in a higher risk category.