Preservation/Keeping Foods for Longer

Causes and Indicators of Food Spoilage

Microorganisms like bacteria, yeasts and moulds can cause food spoilage. They can alter the taste, smell and look of food, making it unsafe for consumption.
Enzymes present in the food itself can cause spoiling. These enzymes could lead to changes in colour, flavour and texture.
Look out for signs of spoilage such as a change in colour, texture or smell. If the food looks or smells off, it’s better to be safe and discard it.

Methods of Food Preservation

Canning: This method involves heating food to kill the harmful bacteria and sealing it in airtight containers. Canning can preserve food for years if stored correctly.
Pickling: In pickling, foods are soaked in solutions like vinegar or brine (salt water), which create a hostile environment for bacteria, preventing them from multiplying.
Drying: This process involves removing water from food, which slows down the growth of bacteria. Dried food should be kept in a cool, dark and dry location.
Freezing: This slows down the decomposition by turning residual moisture into ice, inhibiting the growth of most bacterial species.
Smoking: This not only adds flavour but also preserves food by exposing it to smoke, which contains antimicrobial and antioxidant properties.

Tips for Keeping Foods for Longer

Always check the use-by dates. Food may be unsafe to eat after this date, even if it looks and smells fine.
Refrigerate or freeze perishable food within two hours of purchasing or preparing.
Avoid putting opened canned foods back into the refrigerator, transfer them into a different container instead to avoid leaching of metal into food.
Rotate your stock. Use up older goods first to reduce waste.
Store foods in correct conditions. For example, potatoes should be kept in a cool, dark, well-ventilated place, while most fruits are best stored at room temperature to ripen correctly.

Understanding the indicators of food spoilage, the methods of preserving food, and best practices for food storage can help increase the shelf life of your food products and minimize waste.