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. 

Food Contamination and Prevention - II

Chemical Hazards

Eating a wide range of chemicals is part of our daily life. Thanks to wider application of agricultural chemicals and food additives, a broader range of safe and wholesome food from different parts of the world is made available to meet consumers’ needs. Today, the international food safety authority, Codex Alimentarius Commission, has already established standards for more than 250 food additives as well as more than 250 agricultural chemicals. Together with natural toxicants and industrial chemicals arising from natural sources or human activities, we might be exposed to more than 700 different kinds of chemicals in the food we eat every day. We discussed various points on chemical hazards time to time as well as allergens and remedies.  But this article intends to discuss more practical aspects of chemical hazards and the preventive controls that can be used to eliminate or minimize such contaminations. The chemical contamination mostly accidental, but it is sometimes intentional where sabotage can happen due to intentional contaminations. Thus harmful chemicals may disrupt body metabolism, cause cancers, damage genes, alter organ functions, affect reproduction and development, etc. examples are aflatoxins that can increase the risk of liver cancers whereas mercury can affect developing brains in fetuses, infants and children. However, some food chemicals do cause acute effects, e.g. ciguatoxin poisoning.

According to the dictionary meaning, “chemical hazards are chemical agents that have the potential to cause adverse health effects in humans”. Chemical hazards can occur at any point during harvesting, storage, processing, preparation and service. The presence of chemical hazards in food is usually less immediately apparent than that of bacteria and other biological hazards. However, Chemicals are part of our life, because we are bag of chemicals and what you eat is what you are if you put it in a very simple way. Thus unwanted chemicals can enter into the foods during various stages. When considering growth of plants and animal which are our major source of foods, there are various chemical contaminations such as veterinary drugs, fertilizers, pesticides and environmental contaminants like dioxins, lead or mercury, etc. On the other hand foodstuffs can be contaminated during processing, i.e. oil, cleaning chemicals, insecticides, etc. The next chemical contamination can happen during transportation due to the spillages and leakages. Furthermore, rest of the chemical contaminations may be possible during sale of the food item, i.e. cleaning chemicals, insecticides and such chemical leaking as plasticizers from packaging. The major problems with chemical contaminations are acute poisoning, long-term illnesses or cancers. 

Thus acute toxicity caused by food-borne chemical contaminants is now very rare in developed countries, but their much more concern now is exposure to low levels of toxic chemicals in the diet over long periods. In some cases this can lead to chronic illness and there is also the risk that some contaminants may be carcinogenic. A huge range of potentially toxic chemicals may contaminate food, but some of the main classes of contaminant important in food safety, because these chemicals are present in our food for different reasons, which are:

Food additives that are intentionally added to achieve certain technological functions during food processing, e.g. preservatives (e.g. benzoic acid) can inhibit microbial growth and colour retention agents (e.g. ascorbic acid) can retain or stabilise the original food pigments.

Environmental pollutants such as heavy metals (e.g. mercury, lead) and persistent organic pollutants (e.g. dioxins) that are entered the food chain as contaminants.

Chemicals formed during certain food processing or cooking conditions (e.g. acrylamide).

Residues of agricultural chemicals present in the raw materials, resulting from previous application of pesticides and veterinary drugs during production and storage of food crops and animals.

Some naturally produced toxins by microbes or sea animals, e.g. aflatoxins in peanuts, ciguatoxin in coral fish.

Some naturally present components of food, which may cause adverse reactions under certain conditions, e.g. phytohaemagglutinin in inadequately cooked pulses and beans, allergic substances in peanuts and milk, etc.

The number of chemical hazards is at least hundred times more than that of biological hazards.

The potential of these chemicals to cause adverse health effects in humans is of particular concern to the general public.

Contaminants from packaging and food contact materials (e.g. plasticizers)

Cleaning and sanitizing chemicals

Adulterants (e.g. illegal food dyes)

Furthermore, when toxic chemicals used for pest control or for cleaning and sanitizing food contact surfaces and food preparation equipment come into contact with food, the food may be contaminated by those chemicals. Toxic metals such as copper, brass, cadmium, lead and zinc can be a source of chemical contamination. Zinc, used in galvanized containers (garbage cans) and in gray enamelware containers which may be plated with antimony or cadmium, can make acidic foods such as orange juice or tomato sauce and pickles poisonous. Pottery dishes with lead glazes should not be used to prepare or serve food. However, most possible chemical contaminations, are taken place due to use of cleaning chemicals or due to the byproducts of microbial contaminations such as aflatoxins, mycotoxins etc. The major contamination of cleaning chemicals are mostly the taint, where such chemicals must not be used in food production premises, i.e. phenols, or perfumed soaps, especially those who are handling dairy or fatty foods. Thus all the cleaning chemicals or materials must be kept properly labeled containers in a spate store under restrictions of use with authorized persons to obviate any risk of contaminations.

The presence of chemicals is, however, regulated to protect public health, making reference to safe reference values established by international authorities. Only when dietary exposure exceeds the safe reference value, public health may be at risk. Mere exposure to chemicals should have no cause for undue concern.

Intentionally added chemicals help to maintain a food’s freshness or to enhance flavors in foods. Check the food ingredient label for more information about the additives, which give you a list of food preservatives such as sodium benzoate, potassium sorbate, potassium metabisulphite, etc. or flavour enhancers such as MSG, and acidulants like citric acid or food emulsifiers. Excessive use of any of these can be causative to humans and some additives have been linked to cases of lethal allergic reactions; particularly among sensitive individuals, in particular, asthmatics. Food service establishments are prohibited by law from using sulfites to maintain product freshness. However, they are still approved for use in some food processing operations, for example, processing shrimp and manufacturing wine. If they are used, the product must be clearly labeled.

Preventive Controls for Chemical Contaminations in Food Manufacturing  

The control of these chemical contaminations are not easy, however following concerns may help you improving the problems in chemical contaminations.

Purchase of regulated and certified raw materials form trusted suppliers.

Frequent and scheduled internal audits and supplier audits.

Regular testing of raw materials and end-products through accredited third party laboratories.

Collection and application of new and modern food safety knowledge regarding the product manufactured.  

Regular training of food safety teams and updating their knowledge as well as all food handlers in the production floors.

Careful use of additives, through authorized persons with written instructions for applications.

Control of all chemicals and preservatives under specific regulations without access for all the employees under lock and key conditions.

Control of chemical applications in cleaning and sanitation programs with written instructions and authorized operatives in the presence of a supervisor for guidance.

Use of approved food grade cleaning chemicals, food additives, preservatives etc. under FDA, CODEX, WHO or any other national/international regulatory authority’s recommended concentrations based on the consumer requirements of the concerned country.

“All substances are poisons; there is none which is not a poison. The right dose differentiates a poison from a remedy”

~ Paracelsus, Father of Toxicology