Food Safety and Food Poisoning
What is food poisoning? It is an acute illness, usually sudden, caused by the ingestion of contaminated or poisonous food. The symptoms of food poisoning are:
1. nausea: a sick feeling as if you are about to vomit
2. illness – vomiting
3. Bowl pains – gripping pains in the stomach area
The main causes of food poisoning are:
1. Bacteria – the most common
2. Viruses, which are smaller than bacteria, are normally found in water.
3. Chemicals – Insecticides and herbicides
4. Metals – lead pipes, copper pans
5. Poisonous plants: poisonous mushrooms, kidney beans (undercooked)
bacteria It is the most common form of food poisoning, so it is important that we know more about them. Bacteria are tiny insects that live in the air, in water, in soil, on and in people, in and on food. Some bacteria cause disease. They are called PATHOGENIC bacteria. Some bacteria cause food to rot and spoil, they are called SPOT bacteria. There are four things bacteria need to grow. These are:
Heat. They love the body temperature of 73 degrees, but can happily grow up at 15 degrees. They grow most easily between 5c and 63c. This is known as the DANGER ZONE
Weather. Each bacterium grows by dividing in half. This takes time, on average every 20 minutes. This is known as BINARY FISSION. Imagine, a single bacterium splitting in half every ten minutes can become more than a million in 3 and a half hours.
Food. They like foods rich in protein, such as poultry, cooked meat, dairy products, shellfish, cooked rice, stews, and sauces.
Humidity. They need water, and most foods have enough water or moisture for bacteria to thrive.
Some bacteria can form a hard protective sheath around themselves, this is called a SPORE. This happens when ‘the going gets tough’, when it gets too hot or too dry. So they are able to survive very cold or hot temperatures and can even be present in dry food. Once the right conditions return (5 – 63c), the spore breaks out of its protective shell and becomes a growing poisonous bacterium again.
Bacteria and food poisoning
We have established that the presence of bacteria is one of the most common causes of food poisoning; the presence of poisonous chemicals can also cause food poisoning. There are a number of potentially toxic chemicals present in food. For example, potatoes that have turned green contain the toxic substance Solanine, which is only dangerous when eaten in excess.
Rhubarb contains oxalic acid: the amounts present in the stems that are normally cooked are relatively harmless to humans, but the higher concentration in the leaves makes them very dangerous to eat.
A toxin is a poisonous substance that can be produced by the metabolism of a plant or an animal, especially certain bacteria. Toxic food poisoning is caused mainly by staphylococci in the UK and, more rarely in this country, by Clostridium Botulinum.
The foods most commonly affected by staph are:
• Feet of meat
• Sliced meats
• Cakes with sauce
• Synthetic cream
50-60% of people carry staph in their nose and throat and are present in nasal secretions after a cold. Staphylococci are also present in wounds and skin infections and find their way into food through the hands of an infected food handler. Hence the importance of keeping all wounds and skin conditions covered. Although staphylococci are easily killed by thorough cooking or reheating, the toxin they produce is often much more resistant to heat and may require a higher temperature or longer cooking time for complete destruction.
Clostridium botulinum food poisoning, known as botulism, is extremely serious. This produces a potentially deadly toxin that is the most virulent poison known. The foods most commonly affected by Clostridium botulinum are:
• Improperly processed canned meat, vegetables and fish.
During the commercial canning process, every precaution is taken to ensure that each part of the food is heated to a temperature high enough to ensure complete destruction of any Clostridium botulinum spores that may be present.
YEASTS AND MOLDS: Microscopic organisms, some of which are desirable in foods and contribute to their characteristics. For example, cheese maturing, bread fermentation, etc. They are simple plants that look like whiskers on food. To grow they need heat, moisture and air. They are killed by heat and sunlight. Mold can grow where there is too little moisture for yeast and bacteria to grow. Yeasts are single-celled plants, or organisms larger than bacteria, that grow on foods that contain moisture and sugar. Foods that contain a small percentage of sugar and a large amount of liquid, such as fruit juices and syrups, can ferment due to yeasts. Yeasts are destroyed by heat.
VIRUSES – microscopic foodborne particles that can cause illness. For example, Hepatitis A (jaundice). Unlike bacteria, viruses cannot multiply or grow in food.
PROTOZOA: single-celled organisms that live in water and are responsible for serious diseases such as malaria, usually transmitted by infected mosquitoes, and dysentery. These foodborne infections are mainly contracted abroad.
ESCHERICHIA COLI – E Coli is a normal part of the intestines of man and animals. It is found in human feces and raw meat. E coli causes abdominal pain, fever, diarrhea, and vomiting. High standards of food hygiene and cooking must be applied. Raw and cooked meat must be stored at the correct temperature and cross-contamination must be avoided.
SALMONELLA – is present in the intestines of animals and humans. Affected foods include poultry, meat, eggs, and shellfish. Prevention should include:
• good standards of personal hygiene
• elimination of insects and rodents.
• wash hands, equipment, and surfaces after handling raw poultry
• do not allow carriers of the disease to handle food.
There are three methods to control bacteria:
1. Protect food from airborne bacteria by keeping it covered. To avoid cross-contamination, use separate cutting boards and knives for cooked and raw foods. Use different colored boards for particular foods. For example, red for meat, blue for fish, yellow for poultry, etc. Store cooked and raw foods separately. Wash your hands often.
2. Do not keep food in the danger zone between 5c and 63c for longer than absolutely necessary.
3. To kill bacteria, subject bacteria to 77°C for 30 seconds or higher temperature for less time. Certain bacteria develop into spores and can withstand higher temperatures for longer periods of time. Certain chemicals also kill bacteria and can be used to clean equipment and utensils.
The main food hygiene regulations of importance to catering are: Food Safety (General Food Hygiene) Regulations 1995 and Food Safety (Temperature Control) Regulations 1995. These implemented the Food Hygiene Directive of the CE (93/43 EEC). They replaced several different regulations, including the Food Safety (General) Regulations of 1970. The 1995 Regulations are similar in many ways to the earlier regulations. However, as with the Health and Safety legislation, these regulations place a strong emphasis on owners and managers to identify safety risks, design and implement appropriate systems to prevent contamination, these systems and procedures are covered by the Hazard Analysis and Critical Control Points (HACCP). ) and/or Insured Catering Insurance. The regulations impose two general requirements on the owners of food businesses:
• Ensure that all food handling operations are carried out hygienically and in accordance with the ‘Hygiene Rules’.
• To identify and control all potential food safety hazards, using a systems approach, be it HACCP or assured safe catering.
• In addition, there is an obligation for any food handler who suffers from or is a carrier of any disease that can be transmitted through food, to notify the employer, who may be forced to prevent the interested party from handling food. Catering establishments have a general obligation to supervise, instruct and provide training in food safety and hygiene consistent with the responsibilities of their employees. Details regarding how much training is required are not specified in the regulations. However, the HMSO Industry Guide to Catering provides guidance on training that can be taken as a general standard to comply with the legislation.
Prevention of food poisoning
Almost all food poisoning can be prevented by:
• comply with hygiene standards
caring and thinking in the head
• ensure that high standards of cleanliness are applied to facilities and equipment
• accident prevention
• high standards of personal hygiene
• physical aptitude
• maintain good working conditions
• keep equipment in good condition and clean
• use separate equipment and knives for cooked and raw foods
• ample supply of cleaning facilities and equipment
• store food at the right temperature
• safe reheating of food
• fast cooling of food before storage
• protection of food against vermin and insects;
• hygienic washing procedures;
• Know how food poisoning occurs
• Implementation of procedures for the prevention of food poisoning.
This has been just a brief overview of food safety. If you are in the restaurant industry or planning to become a cook or chef, it is essential that you learn everything there is to know about the subject. The following links should help fill in the gaps.
Essentially, you need to know the Food Regulations that apply to your own country. There is no point in following the UK Food Safety Regulations if you live or work in Australia, Spain or New Zealand.