Vegetables are vegetables, right? They can be canned, frozen or fresh, but as long as you eat your veggies, you’re good to go. Well, wouldn’t the world be a better place if this were the case?
After all, not everyone has the space to plant their patch of fruits and vegetables, and let’s face it – fresh produce can be expensive. On top of this, many simply don’t have the time to prepare fresh food, and canning or freezing isn’t a practical option.
The fact is that we all want to get the most from what we eat. But what exactly happens when fruits or vegetables are canned or frozen? Does it make any difference?
The Issue of Bioavailability
In terms of food, bioavailability refers to the rate and extent the body can absorb certain nutrients found in food, including fruits and vegetables. When we eat, the nutrients contained in the food are ingested into the bloodstream and transported throughout the body. However, different nutrients can be consumed at different rates and quantities.
The bioavailability of a specific nutrient depends on both internal and external factors. For example, gender and pregnancy are some internal factors, while external factors include the chemical form of the nutrient.
When it comes to macronutrients like carbs, proteins, and fats, they have a high bioavailability rate of more than 90 percent. Vitamins and minerals, on the other hand, can vary depending on how they are consumed.
For example, cooking or pureeing plant foods can increase the rate at which the nutrients are absorbed. Say you eat raw carrots or spinach; you can get high sources of fiber but only a fraction of the carotenoids. On the other hand, cooking these vegetables increases the number of carotenoids and reduces the amount of fiber absorbed.
Generally, our bodies can easily absorb vitamins A, D, K, and E if these vitamins are consumed along with fats. This means that the compounds found around fruit and vegetables can affect the bioavailability of their nutrients.
Now that we understand the concept of bioavailability, let’s get the facts in. Are there nutritional differences among frozen, canned, and fresh vegetables? The answer may surprise you.
Canned Fruits and Vegetables
Canned fruits and vegetables are a practical solution to help you make healthy choices, especially when you are on a tight budget or fresh produce is out of season. Since they don’t expire quickly, they can last for weeks, which saves time going to the market regularly. The only problem with canned produce is that they undergo some processing.
From bleaching to adding syrups and salt, these additives can bring health risks to supposedly healthy food. Sodium is one of the additives used to preserve canned goods.
Since the overconsumption of salt is linked to a host of health problems, canned vegetables may not sound like a smart choice. In addition to salt, many manufacturers use processing techniques that break down essential nutrients like nitrates. Nitrates play a critical role in controlling blood pressure and managing cardiovascular health.
Another danger that comes with canned goods is the presence of BPA, or bisphenol-A. This chemical has been connected with the increased risk of cancer and also adds acidity to the produce.
Despite these possible issues, a study conducted by Michigan State University showed that canned goods could provide a healthy alternative that is also affordable. According to the study, canned goods have the following benefits:
- Longer shelf life, which makes meal preparation easier
- A lower-cost, which makes them available to more families
- Safe to eat since canning removes the risk of foodborne illnesses
- Similar nutritional content to fresh and frozen produce
The secret to enjoying canned goods that still have reasonable nutrition value is to check the labels. Select canned goods that have no added sugar or sodium and use their natural juice as storage.
The Truth About Frozen Produce
In most cases, frozen produce undergoes little or no processing, except the occasional blanching before freezing. Blanching reduces the expected change in color, flavor, and nutritional value. Since fruits and vegetables that are frozen are usually picked at their peak of ripeness, they’re often the most nutritious.
Freezing helps retain the nutritional content of both fruits and veggies. This is, of course, if you consume them within a few months. The longer fruits and vegetables are frozen, the higher the chance that some nutrients begin to break down. A study showed that, if frozen produce is stored for more than a year, nutrients like vitamin C and B can start to breakdown.
The time when certain nutrients can be lost is during blanching. The blanching process takes a few minutes and is essential to maintain the flavor, color, and texture of the product. Unfortunately, it can also result in the loss of nutrients like vitamin C and B; however, if fruits are not blanched, this does not apply. In general, nutrient reduction ranges from 10-80 percent, depending on the type of fruit and vegetable and the length of blanching.
On the positive side, some research suggests that freezing produce can retain the antioxidant properties despite the loss of water-soluble vitamins.
Fresh Fruits and Vegetables
When it comes to fresh fruit and vegetables, it is easy to assume that these are the best options with the highest nutritional value. But this depends on whether a fruit or vegetable is post-harvest ripened or vine-ripened.
Post-harvest ripened fruits and vegetables are picked when they are not that ripe, and they ripen during transport. Vine-ripened fruit or vegetables, on the other hand, are pulled and sold ripe. So how does the nutritional value of these two fresh produces compare?
According to one study, ripening berries show pre-harvest weight loss and an increase in the potassium and content levels when ripe. In this case, the berries have more time to absorb nutrients from the soil, which means the longer they stay in the ground, the higher the nutritional value.
However, this is not true for all fruits and vegetables. Some fruits and vegetables absorb minerals and vitamins from the soil during their early stages, which means post-harvest ripening doesn’t affect their nutritional content.
So in the debate between post-harvested and vine harvested fruits and vegetables, studies suggest that the nutrition value is equal. In some cases, post harvested produce can even be higher in nutritional content, depending on factors like the soil, farming method, storage, and season.
Fresh Foods vs. Canned vs. Frozen
From everything we have just discussed, it is easy to conclude that the best choice is always fresh fruit and vegetables, but this is not always the case. Of course, we would never categorize a fresh fruit or vegetable as unhealthy. However, sometimes, the canned or frozen version may be better.
Here are a few of such cases:
Fresh Peas or Frozen Peas
If you are shopping at the farmers market where you are sure that the peas are newly picked, then it is good to go for the fresh peas. However, if you are shopping at the grocery store, frozen peas are a better option. Why? After 24 hours, peas start to lose their taste. As soon as they are picked, the sugar turns into starch.
Frozen peas, however, are picked at the peak of ripeness. This stops the conversion of sugar into starch and preserves the taste and texture of the peas. When choosing frozen peas, just make sure to find a product that has no added sugar, salt, or sauces.
Fresh Tomatoes or Canned Tomatoes
As you may know, tomatoes are seasonal, so if you are looking to get some vegetables out of season, canned tomatoes may be your only option. However, even if they are abundant, there is one thing that canned tomatoes offer that fresh tomatoes don’t- lycopene. When tomatoes are canned, they are processed through heating, which releases lycopene, a compound that is known to have a wide range of health benefits.
To make sure you are making the healthy choice, choose only tomatoes that are in glass jars that are safe from BPA. If you read the labels carefully and make a smart choice, canned tomatoes can be a better option than fresh tomatoes.
Fresh Broccoli or Frozen Broccoli
In some cases, frozen vegetables can be a better choice than fresh vegetables, as we have seen. However, when it comes to broccoli, it is best to stick with the fresh produce. Frozen broccoli lacks the texture we love and is often watery and mushy when cooked. Although it reduces the time for preparation, those extra minutes chopping may be worth your while.
Fresh Lemon Juice or Bottled Lemon Juice
One of the reasons many of us rush for bottled lemon juice is because we want to avoid the task of manually squeezing the lemons. Although this is understandable, you should know that bottled lemon juice often has additives like sugar, acid, and water. These additives not only influence the nutritional value of lemon but also affect the taste. The solution – stick to fresh lemons!
Fresh Spinach or Frozen Spinach
Have you ever wondered why Popeye eats canned spinach instead of raw? Well, he knew the nutritional value in a can of spinach is more than a cup of spinach.
For you to get the same nutritional value in a ten ounce can of frozen spinach, you’d have to harvest your whole garden. So if you want to get value for your money, go for frozen spinach, which is rich in fiber, iron, calcium, and foliate.
Both Fresh and Frozen Produce Decline with Storage
Now that it is clear that whether to buy frozen or fresh produce depends a lot on the type of fruit or vegetable, there is something else we want to note. Whether you choose frosted or fresh food, both have a decline in nutrient value during storage.
One study examined the effect of storage conditions on a range of fresh and frozen fruit. The researchers reviewed six fruits and vegetables, namely: baby sweetcorn, blueberries, raspberries, peas, green beans, and cauliflower. These six fruits and vegetables were analyzed using methods for measuring vitamin C, polyphenols, carotenoids, and anthocyanin.
After three days, they concluded that:
- Frozen spinach had lower levels of vitamin C than fresh spinach.
- Frozen broccoli and carrots had equal levels of vitamin C with their fresh counterparts.
- Frozen and fresh spinach had similar levels of B-Carotene.
- Frozen Brussels sprouts had higher levels of vitamin C than fresh sprouts.
The study suggests that, after three days of refrigeration, the nutritional value of fresh vegetables was lower than those of frozen varieties.
The vitamin C content in fresh vegetables starts to decline right after harvest and continues to decline during storage. However, antioxidants like carotenoids can increase during storage.
As you can see, there are advantages and disadvantages to fresh produce, canned, and frozen food. Here is a summary to help you make the right choice:
Frozen produce pros:
- They stay in a fresh state even after many days, which allows you to continue to make healthy choices.
- Since they are frozen at a time when they have the highest nutritional content, they can be more nutritious than fresh vegetables.
- In terms of dietary fiber, the content of frozen vegetables is similar to that of fresh vegetables.
- Frozen vegetables are often more affordable than fresh vegetables, allowing you to enjoy them all year round.
Frozen produce cons:
- If blanching is used before freezing, the levels of water-soluble vitamins like vitamin B or D can drop drastically.
- To help increase the shelf life, preservatives may be added to frozen vegetables. Sodium is a common additive that can hurt your health.
Canned produce pros:
- The long shelf life is one of the enormous advantages of canned fruits and edibles.
- Canned produce is also affordable and convenient, allowing you to stock on items for the whole year.
- Since canned food is often harvested during peak ripeness, their nutritional content may remain.
- The phytochemicals in vegetables can be enhanced with the canning process, so you can get more nutrients out of them compared to fresh.
Canned produce cons:
- The taste of canned fruits and vegetables is not as good as fresh produce.
- Many canned goods use sodium as a preservative.
- Canned products may also contain botulism, which is rare but possible.
When it comes to selecting which of the two to choose, canned or frozen produce, it is always best to go for frozen. However, for some fruits like tomatoes, canning offers more nutritional value and the added nutrient lycopene, making canned tomatoes better than frozen or even fresh. The safest way to get safely frozen produce is to freeze it yourself. Here is a quick guide to freezing fruits and vegetables:
How to Freeze Fruits and Vegetables
- Wash the fruits carefully, and remove all damaged parts before freezing. If you are freezing cranberries, blueberries, or currants, you won’t need to add syrup, but other fruits may need a sugar-based coating.
- If you are freezing soft and delicate fruit like berries, arrange them carefully on a baking sheet. Make sure they are arranged in a single layer without any lying on top of one another. Freeze them like this, and then transfer them into a bag or container.
- For fruits like apples and peaches, you will need to treat them with vitamin C to prevent browning. You can purchase ascorbic acid at the local drugstore. Mix 1/2 a teaspoon of vitamin C powder with three tablespoons of water, and sprinkle this over the cut fruit.
- Before you freeze vegetables, it is best to blanch them briefly in boiling water.
- After balancing them, immerse them in ice water to stop them from cooking, and then dry them with a paper towel.
- Once dry, pack the vegetables nicely in a zip-lock bag or container, and make sure to seal it well.
Packing fruits and vegetables in the freezer is a critical process to ensure the best result. Make sure that there is no moisture or air inside the package. As much as possible, only pack frozen fruit and vegetable in air-tight containers that can keep moisture away or use freezer bags.
Before you stack your fruits and vegetables in the freezer, make sure the setting of your fridge is at its coldest. When you are ready to use your frozen produce, be careful of how you thaw them. For vegetables, it is safe to put them in boiling water directly, but fruits need to thaw at room temperature.
The question of which is best between canned, frozen, and fresh fruit and vegetables is a common one. Although experts always promote fresh vegetables, in today’s world, this may not be a practical option.
Generally speaking, frozen vegetables and fruits have the same nutritional value as their fresh counterparts. Although few nutrients may be lost during the blanching process, this loss is very little, and you can be sure that you are still getting most of the nutrition.
When it comes to canned produce, a lot depends on the process used in the canning, including the preservatives added. In some cases, canned food is even healthier than fresh or frozen, such as in the case of tomatoes. However, most of the time, you just have to be careful and look out for sugar, sodium, and other preservatives when choosing canned goods.
There are pros and cons to all of the options, so it depends on your lifestyle, needs, and preferences. The important thing is to try and eat a healthy diet rich in fruits and vegetables, no matter where they come from.