Frozen and tinned foods can be just as nutritious as fresh produce—here's how
Freezing lowers the quantity of vitamins misplaced after harvesting. Credit score: SerPhoto/ Shutterstock

The continuing value of residing disaster and fruit and vegetable shortages have left many individuals worrying about how they’ll get these vital meals of their food regimen. But regardless of this, many individuals should still keep away from frozen and tinned produce within the perception that recent produce from the grocery store is best.

Nonetheless, not solely can frozen and tinned produce be simply as nutritious as recent fruit and veggies, in some circumstances they might truly be extra nutritious.

Some individuals shrink back from frozen and tinned meals as a result of they’re technically categorised as “processed meals”. Whereas these meals could embrace preservatives, these components are tightly regulated and have no antagonistic impact on well being. To not point out that the preservation processes used to forestall these meals from spoiling are literally the rationale they’re capable of keep so many vital vitamins.

Nutrient high quality

Vegetables and fruit start to lose vitamins as quickly as they’re picked. They’ll lose as much as half of some vitamins inside a few days of being harvested.

Nutritional vitamins similar to vitamin C are particularly vulnerable to being misplaced after being picked. Inexperienced peas lose about half of their vitamin C inside the first two days after harvest. Related losses are noticed in broccoli and beans.

There are various the reason why these vitamins are misplaced after harvest. First, publicity to gentle and air can provoke a chemical course of referred to as photo-oxidation, which causes vitamins to interrupt down. As well as, pure enzymes current in meals may break down the vitamins. Microorganisms from soil, air and water may discover their approach into meals and feed on the vitamins.

However the strategies used to freeze and might meals each forestall spoilage and decrease the quantity of vitamins misplaced from the product, as they cease these processes of their tracks.

Canning entails including warmth into meals—sometimes utilizing temperatures between 120-140℃ to protect them. Though meals are solely subjected to those temperatures for a couple of minutes at a time, this inactivates sure enzymes and destroys most microorganisms, stopping the meals from spoiling whereas making certain many vital vitamins aren’t misplaced.

Freezing, alternatively, removes warmth from the meals. By reducing its temperature sufficient that the water within the meals freezes (round -20℃), this slows down the chemical reactions that happen in meals—once more, stopping vital vitamins from being misplaced. It is also frequent apply to blanch meals previous to freezing. This additionally inactivates the pure enzymes within the meals, stopping additional nutrient loss.

Thermal processes (similar to canning and blanching) can themselves result in some inevitable nutrient loss. However the extent of this loss is dependent upon the meals and the vitamins they comprise.

Canning usually results in a a lot larger lack of some vitamins than blanching and freezing. It’s because it employs larger temperatures and harsher processing circumstances, with most fruit and veggies needing to be boiled in water earlier than being sealed.

Carrots, for instance, lose little or no vitamin C throughout freezing. However they will lose a important proportion of their vitamin C throughout canning as a result of it is a water-soluble vitamin—which means that it is simply damaged down in water, particularly after being degraded by warmth.

In distinction, vitamin A loss is a lot decrease throughout canning because it’s extra steady in opposition to warmth. In actual fact, extra vitamin A is misplaced throughout the freezing course of.

Vital vitamins

Although some vitamins could be misplaced throughout the blanching, freezing and canning processes, in lots of circumstances the meals nonetheless retain extra vital vitamins than they’d if picked simply earlier than peak ripeness and shipped to their vacation spot grocery store. For instance, analysis exhibits that the vitamin content material of frozen blueberries is comparable—and typically even larger—than that of recent blueberries.

And whereas tinned peaches could lose some vitamins throughout the canning course of, there’s then just about no change of their nutrient ranges even after three months in storage. The identical is true of many different canned and frozen produce, similar to peas, sweetcorn and broccoli, which maintain a lot of their vitamins even after a yr in storage.

The identical applies to different compounds current in meals. For instance, polyphenols—pure compounds present in most fruit and veggies, a few of which have been linked to higher coronary heart well being—could be preserved for longer by means of freezing.

Finally, whereas there could also be some variations within the vitamins accessible in recent versus frozen or tinned produce, nobody sort of meals is considerably higher than the opposite. Nicely, usually.

The exceptions embrace lycopene in tomatoes, the compound that provides tomatoes their pink coloration, which is definitely larger in canned tomatoes than recent tomatoes. There are a number of causes for this—such because the excessive temperatures used throughout canning serving to launch extra lycopene. And since it’s linked with a decrease threat of heart problems, you might need to take into account shopping for canned tomatoes as an alternative—or canning recent tomatoes your self.

Frozen and canned fruit and veggies are a good way of getting the dietary advantages of recent produce with out breaking the financial institution. And within the midst of our present meals shortages, they could be a extra accessible and longer-lasting possibility.

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Frozen and tinned meals could be simply as nutritious as recent produce—this is how (2023, March 21)
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