The four golden rules of good food hygiene elaborate the four stages in which particular care should be paid to avoid food contamination by pathogenic food bacteria.
Here are the four golden rules of food hygiene:
- Buy food from a safe source
- Prevent bacteria from entering your food
- Prevent the multiplication (or growth development) of bacteria in your food
- Destroy bacteria on utensils and work surfaces
So lets look at the four points one by one.
1) Buy food from a safe source
Make sure that you buy food from a supplier that is well known and reputable. It is important that all foods be within their expiry date and stored in appropriate conditions in the shop.
Counters should be kept clean, likewise all machines such as meat grinders and meat slicers.
Food Freezers and food chillers should display their temperatures and should be set at less than 5 degrees centigrade for chilled products and -18 degrees centigrade or less for frozen products.
All packaging should be original and not tampered with or forged. If they have been tampered with this indicates that the product is not original and had been produced by a fraudulent company. Do not buy these products under any circumstances because they threaten your health severely.
All reputable food retail outlets should display an up to date licenses’ from all the necessary licensing bodies that are needed to sell the products in the store. Check with your local authority to find out what licenses’ a shop or a supermarket must have to be open for business in your area.
2) Prevent Bacteria From Entering Your Food
Ok! This is the pace to tell you a little about bacteria and how they multiply. All bacteria, when they have the correct conditions begin to multiply. The conditions that they need are, 1) a temperature of above 10 degrees centigrade, (some say 5 degrees).
The second thing they need is a food source. Bacteria break down all organic matter and use the basic food molecule which is the mono-saccharide glucose.
Bacteria need only 20 minutes to adjust themselves to a new food source. E.G.. Supposing a bacteria was on a sugar food and suddenly found itself on fish, it would need 20 minutes to adjust.
The third thing bacteria need is a source of water which they use to move about in and for the osmotic action to get the food source into their cell.
On attaining suitable conditions bacteria then commence to reproduce at a rate of one division of the whole colony every 20 minutes. E.G. If you had 1000 bacteria on a piece of food to begin with you will have one million bacteria after 20 minutes. In the next 20 minutes the number would jump up to 10,000,000. After that the numbers are astronomical!
Keeping bacteria from getting into your food is down to prevention of cross contamination.
Cross contamination of food can come from direct or indirect contact with other food sources, unhygienic, injoured or sick humans & animals like mice, rats, pets and a vast array of insects that can get into food.
It can also come by putting the food on unclean surfaces and containers or by allowing different kinds of food to come into contact either directly of indirectly through water or air.
In good professional kitchens there are different fridges for different functions. For example, there is one fridge for dairy, another for cold fresh vegetables and another for food that has either been cleaned or cooked.
As home owners we do not usually have the luxury of having different fridges therefore it is advised to keep cooked foods at the top of the fridge and raw materials to the bottom in closed containers. This way the risk of contamination is lessened.
Eggs especially should be kept in a closed egg containers because they have many bacteria on their outer shells.
Remember to wash your hands and arms to the elbow before preparing food. Cut your salads first and then go onto the foods that are to be cooked making sure to thoroughly wash your board before moving onto a different food.
Wash all surfaces before and after work with a good detergent. Put cloths into the wash after each usage. Always start with a clean cloth.
3) Prevent the multiplication of bacteria in your food
As Stated above bacteria need the correct conditions to divide themselves. To do this they need A) the right temperature, B) Food and C) water.
It follows, then, that food should be stored at the lowest possible temperature to keep bacteria dormant. Also, do not allow your meats, fish or eggs to come into contact with water before you cook it.
Cook your food at the earliest possible moment and after it is cooked keep it at a temperature of at least 70 degrees centigrade until it is served. If this is not possible, sool in quickly in small amounts and freeze it as soon as possible.
If you have to cool your food, do not put hot food in large containers into the fridge. Divide it up into smaller containers and do not stack them in such a way that air cannot circulate around the containers. Once cool freeze if possible. In commercial kitchens blast chillers and blast freezers help to prevent bacterial growth by lowering the food temperature more quickly and help to prevent the deterioration of the quality of your food
When thawing food, do it in the fridge in a closed container. Remember, it’s better to plan a meal a couple of days ahead of time than to have a couple of days sick in bed.
Once thawed, cook the food as soon as possible.
The best way to destroy all bacteria is to cook it in a pressure cooker. This way the combination of increased temperature and increased atmospheric pressure will completely sterilize the food.
4) Destroy all bacteria on utensils and work surfaces
This rule speaks for itself. Wash your surfaces after each usage with hot detergent and water.
Likewise, wash all utensils in hot water and washing up detergent. The water should be so hot that you need gloves to tolerate the heat.
Store pots, pans, plates, cutlery and other utensils in a clean and dry place. Make sure that they are dry before storing them away. Use a clean dish towel every time. Stack bowls and cooking trays undide down to ensure water drainage. Stagnant water is dirty water and will produce bacteria no matter how well you washed the utensils.
Heat crockery to 80 degrees centigrade before serving. This will prevent contamination even Further.