Nutrition Advent Calendar – Day 22
Vegetables – Fresh vs Frozen vs Canned
As I planned this topic, I noticed last week that Examine.com had published an evidence based article with the same intention, so I’m simply going to summarise the key points from this, as they have done a great job!
Environmental factors such as soil quality, season, weather, farming methods and storage conditions/duration can influence nutrient content.
Frozen vegetables are typically blanched in hot water for a couple of minutes before freezing. This blanching process is to inactivate enzymes that may cause unfavourable changes in colour, smell and nutritional value. Blanching can release and breakdown some vitamins and minerals but is unlikely to significantly worsen the quality of the produce.
Canned vegetables are usually are more processed. As well as blanching they can be preserved in sugary syrups, contain added salts and other additives which carry their own health risks e.g. increased cancer risk.
Several forms of processing can also breakdown essential nutrients i.e. nitrates (from beetroot) almost entirely.
How you cook food can influence the nutrient availability of certain foods. This helps release nutrients from the food for the body to absorb them more easily.
Some water soluble nutrients (e.g. B vitamins & vitamin C) may be lost during the cooking process of vegetables, but this will not completely destroy the quality of the food. In fact cooking some foods enhances their antioxidant capacity, particularly beta-carotene from carrots, lycopene from tomatoes and lutein from broccoli and courgette.
Take home messages:
How you cook your vegetables, whether they’re fresh, frozen or canned will determine the overall nutrient quality. Cook your vegetables with minimal water & oil to retain more nutrients e.g. steam/slow cook/casserole/roasted.
Choose the vegetables that’s going to get you eat them. Eating any form of vegetables means you’ll obtain some nutrients. Do what works for you!!