Correct storage and use of canned foods.
Commonly, foods in hermetically sealed metal containers (such as aluminium and tinplate) are called canned foods.
Hermetically sealing foods in containers is a method of food preservation. Foods such as fruit, vegetables, meat, fish, or a combination of these foods (e.g. meat and vegetable condensed soup, sauces and fruit salad) are preserved this way. Hermetically sealed containers are also made from glass jars, plastic tubs, flexible pouches and UHT cartons.
How are these foods made commercially?
Foods are washed, prepared and filled into containers and sealed. The food is heat treated producing a commercially sterile shelf-stable product in air tight containers. Heat treatment kills organisms that may spoil the food or cause food-borne illnesses. Contents remain commercially sterile until the container is opened.
Are the containers safe?
Most containers used to hermetically seal foods do not affect the quality or safety of its contents. If the container is damaged during or after manufacture, the safety of its contents can be affected.
How long can I keep these foods?
Foods in hermetically sealed containers have a long shelf life. The storage life depends on a number of factors, including conditions of storage and the nature of food. As a general rule, the lower the storage temperature, the longer the storage life will be.
The sealed containers prevent contamination of food, by organisms that can spoil the contents or cause illness to people, during transportation and storage.
While foods in sealed containers do not change suddenly, slow changes do occur in the container. This may affect the quality of food.
How do I select these foods?
When buying foods, always check the label. In Australia and New Zealand, foods in hermetically sealed containers that have a shelf-life of less than two years require a ‘best-before date’ (date mark) on the label. However, where a food needs to be consumed within a certain time for safety reasons, a ‘use-by date’ is provided. Those that have a shelf life of longer than two years do not need this information.
The label must also include storage conditions required to ensure that the food will keep until the date marked period. Manufacturers also have to provide directions for storage on labels for health and safety reasons.
- Do not purchase any food past its ‘use-by date’. If it has a ‘best-before date’, you could purchase and consume the product after that date, though the food may not be at its peak quality.
- If the label has storage instructions, ensure that the food is stored accordingly at the point-of-purchase.
In addition to the above, food containers should be inspected for:
· swelling and/or leakage | · dented or damaged containers |
· rust and scratches | · damaged seams |
· broken tamper seals | · abrasions, blisters, wrinkles (pouches) |
Do not purchase the food if you see any signs of the above defects.
How do I store these foods at home?
Foods in hermetically sealed containers must be stored according to the storage instructions on the label. If instructions are not provided, then store in a cool dry place. Handle containers carefully to avoid denting or damaging it.
Rotate food in your pantry by using older stock first. Food in hermetically sealed containers is best used within 12 months of purchase to enjoy peak flavour and nutrition.
Before opening
Inspect the container as outlined in ‘How do I select these foods?’ before use. If there are signs of damage, do not use or even taste the food.
Wipe or wash the top of the container before opening. Always use a sharp clean can opener and wash the opener after every use.
Practice good hygiene as if you were handling fresh food – keep all food preparation surfaces and implements clean, and wash hands in warm soapy water before preparing food.
After opening
If the contents have an unusual odour or colour, or if you notice that the inside of a metal container (or lid) is rusted, throw out the contents. Do not taste.
If not used immediately, the contents of the opened container should be emptied into clean plastic or glass container, covered and stored in a refrigerator.
What should I do if I suspect problems with these foods.
You should report any doubtful product to the manufacturer. If you have any concerns about a particular food, you could alert the health department in your state, territory or region.
Further information
Food Science Australia.Storage life of Foods – Fact Sheet 2005. Available at: http://www.foodscience.csiro.au/storagelife2.htm
Canned Food Industry Association.Website available at: http://www.can-news.com.au/
For general food safety information, contact the Food Safety Information Council at: http://www.foodsafety.asn.au/