Ask an expert: is it safe enough to eat?

16th June 2021 | Eativity editors

Next time you’re about to throw packaged food in the rubbish, you should double-check the date on it first. Food safety experts admit that some labelling can be confusing – and you could be throwing out food that’s actually still perfectly safe to eat.

Dr Alison Jones, a food technologist from UNSW School of Chemical Engineering, agrees that food labelling can be confusing for many people, and wants to emphasise the fact that “use-by” and “best-before” dates are actually very different.

“Food manufacturers are responsible for determining the type of date marked on their products to help give consumers a guide as to how long the food product will last before it deteriorates,” she explains. “This is particularly important in determining the quality, nutrition and microbiological safety of food.”

To help you figure out whether all that food in the back of your cupboard is still good or should go in the bin, Dr Jones dishes up the answers in the food labelling debate.

Like to keep your food in jars? Snip out the date on the pack and keep it in the jar.

Q: What’s the difference between use-by and best-before?

A use-by date indicates that the safety of the product can’t be guaranteed after the shown date. Food shouldn’t be eaten after its use-by date, and it’s illegal for retailers to sell food after its use-by date for health and safety reasons. Foods which display use-by dates are commonly those where the spoilage is not clearly discernible before you eat it, for example, fresh pasteurised milk, chilled ready-to-eat foods or deli meats.

Best-before dates indicate that the product may suffer some loss in quality after the displayed date, but should still be safe to eat. That’s provided its packaging is intact and/or it’s been properly stored, since food can spoil prematurely if it’s been subjected to factors including high temperatures, physical damage, broken packaging or high humidity.

Most foods which have a best-before date should still be safe to eat for a little time after, and retailers can still sell food after a best-before date if it’s fit for human consumption.

Foods that commonly carry best-before dates are those which don’t support the growth of pathogens or, in the case of fresh meat, where a later process such as cooking will destroy any bacteria that might be present. Examples of foods that usually have a best-before date are shelf-stable foods such as food in cans and pouches, low water activity foods like lollies, tea, freeze-dried coffee, sugar, salt, cereals and dried fruits. Other examples include acidic fermented products such as yoghurt or sauerkraut, and frozen products.

Someone in a lab coat has spent a lot of time figuring out that little date on your packaged food.

Q: How do companies determine these dates?

Companies conduct vigorous shelf-life studies that put products under various conditions and monitor the type and rate of deterioration in the food. For example, they test the growth of any spoilage microbes, loss of key nutrients, changes to the food’s water activity or physical, chemical or biochemical changes that alter the food’s quality and safety.

If products require special storage conditions in order for the date markings to be effective, then manufacturers can provide specific storage condition statements on the packaging. This is compulsory in the case of a use-by date, where specific storage is essential for the health and safety of the product (and the person who eats it) – so it’s important to keep an eye out for these on food product packaging.

Some foods, such as canned food, don’t need a use-by or a best-before date, although many do. This is because they have a best-before date of over two years, and it gets hard for food manufacturers to give an accurate estimation of how long the food will last.

Q: How long is a food still safe to eat after its best-before date?

That very much depends on the food – the best advice is to look for signs of deterioration, spoilage and/or damage such as mould, slime, rancidity, off-flavours or odours, staling, gas-production or broken packaging. You should also follow any of the manufacturer’s specific storage instructions to ensure the best-before and use-by dates are effective.

For more information on food safety, including an A-Z guide to everything from additives and botulism to yoghurt and zucchini, head to foodsafety.asn.au