冷冻水果和罐装蔬菜便宜，但它们的营养是否和新鲜食物一样？

You probably know fruit and vegetables are good for you, and most of us don’t eat enough of them.

But amid a cost-of-living crisis, buying more fresh food may not seem like a budget-friendly option.

Enter: canned or frozen fruit and veg.

These are usually cheaper and longer-lasting than fresh produce. But are they as healthy? Let’s unpack the research.

First, how much should we be aiming for?

Fruit and vegetables contain important vitamins, minerals and fibre. These support overall wellbeing and reduce the risk of illnesses, such as heart disease and some cancers.

The Australian Guide to Healthy Eating recommends adults eat at least two serves of fruit and five serves of vegetables every day. This includes frozen and canned options.

For example, ½ a cup of frozen broccoli or ½ a cup of canned beans equals one serve of vegetables. One cup of canned peaches or one cup of diced, frozen mango equals one serve of fruit.

Cheap, quick… and low waste?

Most canned and frozen fruits and vegetables are cheaper than fresh produce.

As they generally come pre-chopped and ready to cook, they also cut down on preparation time.

Produce that is canned or frozen also has a much longer shelf life than fresh options. This means they are available year-round, and are less likely to spoil and have to be thrown out.

What about nutrition?

Frozen and canned fruit or veg generally retains its original nutritional value – sometimes better than fresh produce.

For example, the nutritional value of most frozen and canned products is equivalent to fresh fruit and vegetables that have been in the fridge for a week.

But the process of preserving certain foods may actually increase their nutrient content. Apricots are one example, with frozen apricots having a much higher vitamin C content than fresh apricots. This is because vitamin C is used to help preserve the fruit.

Freezing uses low temperatures to delay food spoilage. Industrial freezing methods are effective at retaining the colour and textural qualities of fruit and vegetables, while also maintaining their nutritional content.

However, freezing may damage the structure of food if it causes ice crystals to develop. This can reduce the nutrient content of fruits and vegetables and make them mushy, especially if you thaw and re-freeze them.

Frozen fruits and vegetables are at risk of being contaminated with the bacteria Listeria monocytogenes, which can cause food poisoning. But cooking fruits or vegetables before eating them reduces this risk.

The canning process involves sterilising foods at high temperatures so they can be safely stored at room temperature for long periods. However, being exposed to high temperatures causes some nutrients in the food to break down, especially water-soluble vitamins such as vitamin C. But advances in canning technology are allowing the process to be done faster and at lower temperatures, meaning less nutrients are lost.

What to keep an eye on

There are some things to look out for when purchasing canned fruit or vegetables.

Canned vegetables can have a high salt content, so it’s best to choose products that say “no added salt”. You can also check the nutrition information panel and look for options with the lowest sodium content. Draining and rinsing canned veggies before eating them can also help reduce the amount of salt you eat.

For baked beans in sauce, the sauce may contain added sugar and salt. If you eat baked beans regularly, it’s worth finding a salt reduced option to help lower your sodium intake.

To help reduce your sugar consumption, choose canned fruit options that are canned in juice rather than syrup. Some may also say “no added sugar” on the package.

How to use them

Canned fruits can be eaten as a snack on their own, or with cereal or yoghurt. In many recipes you can often replace fresh fruit with frozen and canned options.

Frozen veggies are great for whipping up a quick meal. For example, frozen peas and edamame only need a few minutes to cook, so can be added last-minute to a stir-fry or stew.

Adding a tin of lentils, chickpeas or beans can bulk out a stew or pasta sauce, while boosting your fibre and protein intake. Given they are already cooked, you can also toss them into a salad that will keep you fuller for longer. Just remember to rinse them first.

For more inspiration, here are some recipe collections that revolve around:

frozen vegetables

canned beans

canned fruits and vegetables

frozen fruits.

What about dried fruit and veg?

Compared to tinned versions, dried beans, chickpeas and lentils – which are all excellent sources of fibre and protein – are even better value and also have a long shelf life. But they can take longer to prepare.

Depending on the product, dried beans, chickpeas and lentils may need soaking prior to cooking or may be ready to add straight to the pot. If in doubt, check the instructions on the back of the packet.

Dried fruits are not recommended as an everyday alternative to fresh, frozen or canned fruit. This is because drying makes them more highly concentrated in sugar. But you can enjoy them as an occasional snack.

Margaret Murray does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.