I don’t just like cooking, I love it, and where appropriate I cook using frozen fruit and veg.
A huge portion of your body’s nutritional needs come from its access to fruits and vegetables – so determining what fruits and veg you should be eating is no small dietary issue.
Let me show you the variables I consider, as a nutritionist, trainer and mother when I go looking for ingredients for the meals we eat at home.
Food Quality
The Raw Deal
Farm Freezer, Friar, Fork
The Three Tier System
The X Factor
Food Quality
When comparing the qualities of categories with one another (in this case, frozen and fresh produce), its important we’re clear on what we mean by ‘quality’.
What is, ‘good quality food’?
Any food, frozen or not, is considered to be of good quality if it meets the following requirements.
- it must possess a total lack of toxic compounds or pathogens
- be easily digestible
- it must possess a high concentration of nutrients
- it’s sensory attributes, such as appearance and smell, must be constant – in the case of frozen fruits and veg – as close to ‘fresh’ ash possible
So with the bar set there, let’s see how Frozen Food compares to Fresh.
The Raw Deal
The truth is that a lot of what makes fruits and vegetables healthy is preserved within them when frozen, assuming the most ideal conditions. And that’s a big part of what makes the quality of frozen fruits and vegetables so high.
It also can’t be overstated how important fruits and vegetables are. Our daily ascorbic acid (vitamin C) requirements each day are 94% reliant on fruits and vegetables (33% fruits, 61% vegetables). They are also the chief source of vitamin A (42%) and fiber. Not only does freezing preserve vitamins in fruits and vegetables, but they also preserve other beneficial plant compounds that help protect against diseases of all kinds.
When frozen vegetables and fruits are compared to fruits and vegetables that have been picked fresh – frozen outperforms fresh after just three days of fresh fruits and veg being removed from the vine!
Farm, Freezer, Friar, Fork
Food that is frozen for commercial sale is picked at the peak of ripeness and, in most cases, meticulously and efficiently processed. But it’s important to understand the variables involved if you’re going to remain a skeptical survivor in the modern food jungle
- Harvesting Time
- Pre-freezing Storage Conditions
- Pre-freezing Processing
- Freezing Techniques
- Post-Freezing Transport Conditions
- Cooking Conditions
Harvesting Time
Most fruits and vegetables are deliberately picked at the peak of ripeness. This is no the case with ‘fresh’ fruit and vegetables in your supermarket, which have been picked days, if not weeks before they are put in your refrigerator. The moment a fruit or vegetable leaves the plant from which it was growing, it ceases to receive nutritional input and it begins to consume its own nutrients to ripen off the vine.
Pre-Freezing Storage Conditions
Vitamin C is an incredibly delicate nutrient and begins to depreciate as soon as the plant has been harvested. Every day that it sits in storage awaiting freezing or processing it is losing nutrients, especially vitamin C. Hot environments amplify this effect. Some foods, like spinach, can lose up to 35% in a single day of storage.
Pre-Freezing Processing
This is actually a process that happens exclusively for particular kinds of vegetables, and it involves heat treating and blanching. In practice this involves briefly submerging them in 80-100C water or by steaming at 100C. This important thermal treatment process is very necessary in order to inactivate enzymes responsible for odor and nutritional loss during storage. It further enhances the washing process, eliminates residue insecticides and enhances color. However, there is a nutritional sacrifice and a change in the texture of most heat treated vegetables. Peas blanched for 3 minutes, for instance, lose 33% of their Vitamin C, 20% riboflavin, 10% niacin and 5% of their thiamine.
Freezing Techniques
Frozen fruits and vegetables are picked at the very peak of their ripeness, when they are nutrient rich, and are generally individually frozen using a nitrogen atmosphere, which preserves the nutrients that oxygen would otherwise degrade. Typically fruits and vegetables are stored at just below -18C.
Post-Freezing Storage Conditions
Defrosting during transport is rarely an issue these days, but remain vigilant for defrosted/refrosted foods. You can do this by feeling the frozen produce with our fingers through packaging. Vegetables/fruits inside that have frozen into a solid mass have thawed and then been refrozen, and should be avoided.
Cooking Conditions
Cooking at high or sustained temperatures will reduce the nutritional value of your food significantly. To the tune of 50%. Cooking is where most of your nutrients will be lost with frozen foods. Cooking frozen foods will result in additional nutritional losses of 10-50% Vitamin C, 0-50% folic acid, 0-40% Vitamin B and 10-40% pantothenic acid. These nutrients in particular are easy to loose at sustained temperatures – so manage your heat!
The Three Tier System
So that’s a lot to take onboard, I know. Fortunately, this is where things get simple.
There’s an easy system you can use to determine whether or not you should be buying the carrots and cantaloupes in your grocery store’s ‘fresh’ or ‘frozen’ sections.
Use this simple scale when shopping.
Local Fresh before Frozen Fresh before Shipped Fresh.
- Local Fresh – is the best of all choices if used within 2 days of purchase. Normally fresh local food at your market or grocery store will be only one or two days old. Harvested at the peak of ripeness. After 3 days off the vine, even when stored in your refrigerator, you’re better off eating frozen
- Frozen Fresh – in frozen fruits you get nutrient levels comparable to freshly picked 1 day old fruits. This is because there’s no pre-freezing blanching process with fruits. For vegetables that require blanching before freezing, the nutrient loss experienced by this heat treatment is significantly lower than the nutrient loss experienced by fresh fruit picked early and transported long distances. It is even superior to fresh fruit picked locally and left on display or storage for 3 or more days. Frozen fruits and vegetables are picked at the peak of ripeness
- Shipped Fresh – this is the lowest end of the food quality ladder. The nutritional contents of foods that have been necessarily picked prior to ripeness, then stored while being shipped for prolonged periods are staggeringly low. By the time you get your hands on them the nutrient loss could be more than 50%. National food will arrive at a grocery store within 5 days, where it will be displayed for up to 3 days. Internationally shipped food can be in transport for weeks.
But remember, food quality is dynamic – some recipes require fresh. Why? Because fresh has an x factor.
The X Factor
There’s something about fresh fruits and vegetables that isn’t there in frozen versions of the same. That’s because the tissues of plants are delicate by design, and when the water inside their cells freezes and expands, the cells burst. This causes a loss of cellular structure, shape and texture.
Some fruits and vegetables suffer the loss of their x factor more than others. With tomatoes and lettuce being on one side of the spectrum, and potatoes and sweet corn on the other.
As a result of this, use frozen foods in preference to fresh foods not only by virtue of their healthfulness, but also their appropriateness. Salads, for instance, should generally be comprised of ‘fresh’ vegetables, but fruit salads needn’t be. A lasagna is a fine place to use frozen broccoli, but a shish kebab cooked over a BBQ demands the fresh stuff.
Hunter Tips
Work these techniques into your frozen-food relationship for the best results.
- Don’t overheat frozen produce. Defrost fruit on the counter or via a quick blast in the microwave if possible. This retains the plant’s phytoactive compounds
- Make a habit of storing your fruits and vegetables at the back of the freezer to avoid them defrosting when the door opens, and to expose them to the lowest possible temperatures
- On that note, keep your freezer door shut whenever possible. Bleeding cold out of the freezer is a surefire way to deplete the quality of everything inside of it
- For the best quality frozen fruits and vegetables, always go for those without added sauces, salts or sugars
- Cooking with frozen fruits and vegetables introduces a variables that experience will quickly accommodate for. Just pay attention. The texture, cooking speed, moisture content and its capacity to seer can all be distinct from the fresh versions you’re used to
- The most delicate Vitamin is Vitamin C. Try squeezing a fresh lemon over your fruits and vegetables before serving, as it’s a Vitamin C rich liquid which will simultaneously re-energize them and make their color instantly brighter!
Looking for something to cook that’s sinfully tasty but embarrassingly healthy to put some frozen vegetables in? Try My Recipes today!