Are Frozen Vegetables Healthy?

What About Frozen Fruits?

Your fresh produce isn’t that fresh and could be lacking nutrients. So are frozen vegetables healthy? What about fruits? Here’s the science.


Frozen Fruits and Vegetables are Better than Fresh

Hey, you like apples? Sure you do! You're no beet-eating Bolshevik. Chomping into a fresh, nutrient-rich apple is apple-pie American and oh-so satisfying.

But here's where I rain some bummer down on you. Most grocery store apples have been chemically treated so they'll last for 12 months, so unless you bought them during apple season (July through early November), you could be scrunching an apple that's the fruity equivalent of the mummified pharaoh, Tutankhamun.

Apples aren't the only foods that are sometimes stored in food distribution warehouses for lengthy periods. Carrots can be stocked for 1 to 9 months. Orange juice is pasteurized and sometimes sequestered in storage tanks for a year.

And there are probably scores of other examples. Clearly, fresh grocery-store produce often isn't so fresh and is likely compromised, nutrition-wise. There's a way to get around geriatric produce, though, and that's by switching to frozen fruits and vegetables.

Why is My "Fresh" Produce So Damn Old?""

It's easy to think all that colorful produce at your grocery store was grown locally, raised by farmers who pushed their wheelbarrows through streets broad and narrow (alive, alive, oh!) to Kroger's so that you could have fresh fruit salad for Sunday brunch.

A nice thought, but totally fakakta, unless maybe you live in California. The "land of fruits and nuts" (an apt nickname, in this case) boasts more than 77,500 farms and grows over 400 different types of produce, much of which of course is shipped to other parts of the country.

Consider too that the U.S. imports 32% of its allegedly fresh vegetables and 55% of its allegedly fresh fruit, none of which is likely jetted-in overnight to your grocery store.

And all those supply-chain problems the country/world is facing? They apply to produce too. Nancy Tucker, Vice President of Global Business Development at Produce Marketing Association (PMA), gives the example of Chilean cherries, 90% of which are shipped to China in recyclable containers and then distributed around China (1).

Once these containers are unloaded, they're filled with some other product and sent to another country, eventually making their way back to Chile to be used again for cherries. However, when something mucks up the delivery chain, like a pesky virus, the containers pile up, so much so that the number of containers leaving China dropped by 25% this last February.

"It's like a dance in a historic movie," explained Tucker. "The dancers move from partner to partner down a chain, but if the music stops the dancers all pile up."

When the produce does get shipped, it's hardly fresh off the vine and its nutrient density has likely diminished.

How the Heck Do You Score Fresh Produce in January?

Then there's the matter of growing seasons, which I alluded to in the opening paragraphs of this article. How do you think people shopping at, say, Sobeys in Buffalo during the winter get their squash? It was of course shipped from warmer climes, most likely California, Arizona, south Texas, or Mexico.

But let's forget about all those shipping and supply-chain problems we currently face and consider a best-case scenario for that squash from Sobeys:

It took a whole day to pick it from the field. It took another to clean and pack it. One more day to wait for a truck and four more days of travel to a terminal market, where it sits one day. Then it travels to a distributor for repacking, which probably takes another day. Then it's trucked over to the local grocery store and placed on the shelf.

That means that the squash has been disassociated from its vine for 9 days. Okay, but a squash has about 14 days before it overripens and loses much of its nutritional value. Better pick that sucker up quick and make your succotash because the squash-clock is ticking.

And that's a best-case scenario. There's a good chance that your produce, squash or not, is a lot older than 9 days, even in normal times, making its nutritional value terribly suspect.

There's a solution, though: frozen fruits and vegetables.

Are Frozen Fruits and Vegetables as Nutritious as Fresh?

The best thing about frozen fruits and vegetables is that they're generally frozen within 48 hours of picking, which locks in flavor and, more importantly, nutrients.

Delicate fruits like berries are subjected to something called cryogenic freezing (which is also what they did to baseball great Ted William's head). They use solid C02 or liquid nitrogen to quickly freeze the fruit (or head), which lessens crystallization. Other, less vulnerable fruits and vegetables are placed on conveyor belts and belted with "air blast" freezing.

It makes sense that the nutrients would be locked in place, but there's research to back it up. Bouzari, et al., in 2014, evaluated the amount of riboflavin, beta-carotene, vitamin C, and alpha tocopherol (vitamin E) in frozen and non-frozen carrots, corn, spinach, broccoli, peas, green beans, strawberries, and blueberries (2).

Here's what they found:

  • Frozen foods showed a minimal loss of vitamin C, compared to big losses in non-frozen, "fresh" varieties.
  • Frozen peas showed an increase in vitamin C and vitamin E over non-frozen.
  • There was basically no difference in riboflavin content between frozen and non-frozen samples.
  • Three of the frozen vegetable varieties had higher amounts of vitamin E than their non-frozen counterparts.
  • The findings were true for fruits and vegetables even if they'd been frozen for 90 days.

The news wasn't all a bowl of frozen cherries, though. For reasons unknown, the frozen peas, carrots, and spinach had lower levels of beta-carotene than the non-frozen samples.

Generally speaking, though, as long as the "chain of freezing" wasn't broken (e.g., some grocery store twit let the frozen produce sit on a loading dock for a couple of hours while they went to see a Spiderman movie), the frozen produce is often as good or better than fresh, and another study shows that the nutrient levels remain stable for at least 6 months (3).

The same is true for most, if not all, the phytochemicals found in fruits and vegetables (4). In fact, in the case of blueberries, freezing actually improves the bioavailability of anthocyanins (5). Apparently, the freezing sometimes creates crystals that disrupt the structure of the plant tissue, thereby making the anthocyanins more accessible.

What About Pesticides?

It's hard to find pesticide-free fruits and vegetables in general, and just because produce is labeled "organic" doesn't mean the farmers didn't use insect and/or mold killing chemicals on it. However, organic stuff usually contains less pesticide than their non-organic counterparts.

That being said, there's a decent chance that frozen fruits and vegetables, since they're washed/soaked/peeled before freezing, contain fewer pesticides in general. All that considered, we might conclude that frozen organic fruits and vegetables would contain the fewest pesticides of all, (aside from the stuff that was raised on small farms that tout their chemical-free practices).

How Do I Prepare Them Without Making Them Mushy?

Regarding frozen vegetables, you don't need to thaw them before cooking. In fact, that's sometimes a mistake as thawing by, say, running tap water over them, allows nutrient-rich solutes to leach out and escape through your plumbing. Likewise, slow thawing allows some of the microbes and enzymes contained in the food to activate and start breaking down the food, contributing to the dreaded soggy vegetable syndrome.

The best way to prepare frozen vegetables is by frying or steaming. Just plop them straight from the freezer into the pan or steamer. Microwaving is acceptable too. To assure crunchiness when using the latter cooking mode, just put them in a dish without water and zap for 4 to 5 minutes.

Frozen fruits can be thawed a little more successfully than frozen vegetables, but why bother? A handful of frozen strawberries or melon tossed into a blender eliminates the need for ice cubes. Toss a handful of frozen blueberries into your oatmeal and they'll thaw before the spoon hits your lips.

Ditch the Frozen Fruit and Vegetable Bias

Most people insist on buying "fresh" fruits and vegetables. They regard frozen produce as "processed" and nothing anyone can say can change their minds. I understand this bias towards allegedly fresh produce – it's extremely common. It is, however, misguided, especially considering the current state of supply chains in the world.

It'd be different if we all lived next to a world-class farmer's market that featured fruits and vegetables most of us had never even seen before, but we don't. Hence, frozen fruits and vegetables appear to be the smartest choice.

References
  1. Can Food Supply Chains Cope with C-19? Bayer Global News. April 12, 2022.
  2. Bouzari A et al. Vitamin Retention in Eight Fruits and Vegetables: A Comparison of Refrigerated and Frozen Storage. J Agric Food Chem. 2015 Jan 28;63(3):957-62. PubMed.
  3. Pallig A et al., Analysis of Polyphenols, Flavonoids and Assessment of the Antioxidant Capacity of Frozen Fruits. Revista de Chimie (Rev. Chim.). 2018 Feb;69(2):445-448.
  4. Mullen W et al. Effect of freezing and storage on the phenolics, ellagitannins, flavonoids, and antioxidant capacity of red raspberries. J Agric Food Chem. 2002;50(18):5197-5201.
  5. South Dakota State University Freezing blueberries improves antioxidant availability. ScienceDaily. 22 July 2014.
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