Correct food handling practice and food storage helps prevent bacteria from contaminating and multiplying on foods. The following action needs to be taken to prevent bacterial contamination:
- Protect food from contamination – handle food properly
- Prevent bacteria from multiplying
- Destroy germs on/in food
Fig. 3.33: The food contamination chain can be broken in several places.
Food can be protected from contamination by handling it with care. Food handlers should think about:
- where food poisoning bacteria come from. They can come from people's bodies, sneezes, coughs, high risk foods, insects, rodents, pets, toilets and dust particles in the air
- the different ways bacteria can get on to the food they are handling, for example, from cross contamination and contaminated hands and clothing
- the correct cooking and storage temperatures which prevent bacteria multiplying
Top of Page
9.1 Correct food handling rulesAlways wash hands with soap and warm water before handling food. Wet the hands before applying the soap. Make sure you rub in between fingers and on the front and backs of hands. Remember to clean under fingernails. Rubbing with soap loosens bacteria. They must be rinsed off with water. (When possible, use hot water for washing the hands.)
Fig. 3.34: Wash hands before handling food and be sure to clean under the finger nails.
Always wash hands with soap and warm water after going to the toilet or touching any parts of the body, such as the skin or nose.
Fig. 3.35: Wash hands after going to the toilet.
- Do not smoke while preparing food
- Handle food with tongs, a spoon or some other utensil which is clean
- When sneezing or coughing always cover the face with a tissue or the hands and turn away from the food. Wash hands immediately after as they may have been contaminated
- Avoid preparing food for others if you have diarrhoea
Fig. 3.36: If sneezing, turn away from the food and use a tissue.
Top of Page
- If food does have to be left standing in the open for a few minutes during preparation always cover it with a lid, clean cloth or cling wrap
- Do not let raw high risk foods touch other foods
- Always clean and sanitise utensils and benches/work surfaces used to prepare high risk foods immediately after the food has been prepared
- Work benches and cooking utensils should always be kept clean
- Make sure insects, rats, mice and other pests cannot get into the food preparation area
- Pets should also be discouraged from domestic kitchens and must never be allowed into a shop or community kitchen
Fig. 3.37: Keep all work benches clean.
- Dispose of rubbish regularly and correctly
- Make sure the floors, walls, window sills and all fixtures in the food preparation area are regularly and properly cleaned
9.2 Correct food storageFood poisoning bacteria can only multiply in the temperature danger zone of between 5°C and 60°C.
However, food poisoning bacteria do not multiply at the same rate throughout this temperature range. They multiply most quickly between 36°C and 38°C, which is around human body temperature.
Above 60°C nearly all food poisoning germs are killed. Below 5°C the germs stay alive but they do not multiply. Keeping food out of the temperature danger zone helps stop the multiplication and growth of bacteria.
Fig. 3.38: The food temperature danger zone.
Top of Page
Food should be stored according to its food type. For example:
- high risk foods such as milk and milk products and fish should be stored in a refrigerator or freezer. They should never be left in the food temperature danger zone
- foods such as fresh fruit and vegetables last longer when they are kept cold, and should be stored in a refrigerator
- dry foods such as flour, breakfast cereals and rice are likely to be attacked by pests and need to be stored in sealed containers
Storing foods in refrigerators and freezersFreezers, including the freezer section in household refrigerators, will keep foods frozen. Frozen foods can last many months depending on the food type. However, some foods are unsuitable for freezing. For example, cheese and processed foods will lose food quality when frozen.
Frozen foods taken from the freezer and allowed to thaw must be cooked or eaten straight away. Thawing means returning the frozen food to its normal soft state by increasing its temperature. It is safest to do this by putting the frozen food into the normal refrigerator compartment, or by defrosting in a microwave oven on the defrost setting.
Once food has been thawed it should never be frozen again. This is because bacteria will grow and multiply in the food during the freezing and defrosting process.
Refrigerators chill foods. Foods which are to be eaten cold should be kept in the refrigerator until they are ready to be served. These foods include milk, cheese, custards, salads and cold meats. Many of these foods will deteriorate (break down) after several days in refrigerator storage and will not be fit to eat.
Storing foods which do not need to be frozen or chilledThese foods include cereals, flour, sugar, unopened canned goods, dried products, sauces and spices. They do not support the growth of bacteria like the high risk/high moisture foods. They can lose quality from being kept too long in storage and their major source of contaminants is pests.
Some bacterial contamination can occur when canned high risk/high moisture foods are kept too long in storage or when containers become broken or damaged during production, transport or storage. Other foods may suffer bacterial contamination from exposure to pests, especially insects and rodents.
Care should always be taken when purchasing tinned foods. Do not buy dented or blown cans. A blown can occurs when gas forms from the action of bacteria in the product. It is easy to tell a blown can because the lid and base will pop when pressed.
When dealing with foods that are normally stored at room temperature, remember:
- canned or packaged foods should be used in rotation, with the oldest used first
- cereals, flour, sugar and other dried foods should be stored in sealed containers to stop the access of pests
- when containers with re-sealable lids are opened, such as sauce bottles, pickle and jam jars, the lid should be put back tightly if all of the food is not used. Check the label for storage instructions as some foods must be stored in the fridge after opening
- when cans without re-sealable lids are opened, such as some sauces, gravies, fruit, meat and vegetables, all of the unused contents should be transferred to a clean container with a tight lid. If the contents are high risk/high moisture foods such as fruit, vegetables or meat this container should be kept in the refrigerator
Top of Page
9.3Correct cooking temperaturesFood poisoning bacteria do not grow at temperatures above 60°C. If the temperature falls into the danger zone between 5°C and 60°C, the bacteria will be able to grow and multiply rapidly.
Before some frozen foods are eaten they will need to be thawed. Foods which are to be eaten hot should be cooked and served immediately while they are still hot. If they are not to be eaten straight away they should be placed in the refrigerator or freezer immediately after cooking.
Cooked foods which have been stored in the refrigerator or freezer must be thawed if necessary and reheated quickly and thoroughly to a temperature of at least 75°C.
No high risk food should be left standing in the danger zone for more than a few minutes.
9.4 Food shops and storesThere are laws which strictly control food handling practices in places where food is prepared ready for sale to the public. This is because there is usually a lot more food involved and more people could be affected by food contamination. Many Indigenous communities now have food outlets that sell ready to eat food or provide meals to schools or elderly people. Therefore, Community Councils must take particular care to follow the correct food handling practices. The requirements are detailed in the Australian Food Standards Code.
Environmental Health Practitioners employed by the Department of Health and local government have responsibility for routinely inspecting shops and making sure that these regulations are followed. These inspections are very specialised, but sometimes the EHP can make occasional visits.
One task that the community can ask the EHP to do is a frequent routine inspection of any food shops and stores in the community. Before doing them alone, it would be necessary for the EHP to learn to do them properly. The best way to do this would be for the EHP to accompany the EHO on a number of shop inspections.
Any EHP wishing to learn how to do shop inspections must contact his/her local EHO.
Top of Page
These inspections will include checking:
- date codes on foods (‘best before’ or ‘use by’ date). Some foods display a date by which they should be used. It is for the information of buyers and is called the date code. When this date has been passed the food is said to be out of code
It is not illegal to sell foods after the ‘best before’ date, but buyers should be careful because such foods could be stale or have lost some of their quality, such as loss of nutrients or taste. It is illegal to sell foods after the ‘use by’ date
- for food contamination. Signs of food contamination include:
- broken packets
- blown cans (the lid or base will ‘pop’ when pressed)
- weevils in packaged dried goods, such as plastic bags of rice. Weevils are a type of insect, and leave webs which can be seen through clear plastic packaging
- meat in shrink-sealed plastic bags will develop gas when contaminated with bacteria. The bag will bubble or bulge under the pressure of the gas
- discolouration and mould on chilled goods
- food storage in freezers, chillers and refrigerators. Raw and cooked foods must be stored separately in freezers, chillers and refrigerators and the cabinets of these storage facilities must be kept very clean
Also, a build-up of frost and ice inside the cabinets probably means that the correct temperature is not being maintained
- storage of dry foods. It is important that dry foods, such as flour, breakfast cereals and sugar, are stored safely. Storage areas for dry goods, including dry foods, are favourite places for rats and mice and checks should be made for signs of these pests
Dry foods should always be separated from household cleaning and other products which may be poisonous or which could spoil the food in other ways. For example, odours given off from these products may poison or flavour the dry foods
- that correct cooking temperatures are used. Where food is prepared on the premises, such as in fast food outlets or school canteens, it is important that all food is cooked at 75°C or hotter to kill harmful bacteria. After cooking, high risk foods should be stored above 60°C. This includes hot foods displayed for sale in shops
- that proper food and personal hygiene practices are followed
- that proper food handling facilities are provided. It is important that all shops where food is prepared provide food handlers with a hand basin, soap and clean, single-use towels, e.g. paper towels
- for evidence of disease-carrying pests. It is important that all premises where food is sold are free of pests, such as rats, mice, cockroaches and flies. Checks should be made for evidence of these pests, such as rat or mice droppings