Quality of Frozen and Canned Foods; Reasons You Should Try Them

In addition to contributing to a healthy diet, frozen and canned foods also have a long shelf life. Canned foods can increase the variety of fruits and vegetables in the diet, as some items may not be widely available. They are also more economical.

FREMONT, CA: Due to the ongoing cost of living crisis and fruit and vegetable shortages, many people are concerned about how they will obtain these essential foods. Even so, many people still believe that fresh produce from the supermarket is better than frozen or tinned produce.

Although frozen and canned produce can be just as nutritious as fresh fruits and vegetables, in some cases, they may be even more so.

Frozen and canned foods are technically referred to as "processed foods" by some people. Despite the fact that these foods may contain preservatives, these ingredients are tightly regulated and have no adverse effects on health. As a bonus, these foods are actually able to maintain so many important nutrients because of the preservation processes that are used to prevent them from spoiling.

Quality of nutrients: The moment fruits and vegetables are picked, they begin to lose nutrients. Within a couple of days of harvesting, some nutrients can be lost.

Vitamin C, for example, is especially susceptible to lose after picking. After harvest, green peas lose about half of their vitamin C. Broccoli and beans also lose about half of their vitamin C.

After harvest, these nutrients are lost for a variety of reasons. Light and air can trigger a chemical reaction called photooxidation, which breaks down nutrients. The nutrients can also be broken down by natural enzymes in foods. Nutrients in foods can also be consumed by microorganisms from soil, air, and water.

As freezing and canning stop these processes, they prevent spoilage and lower the number of nutrients lost from the product. The process of canning involves adding heat to foods, usually between 120°C and 140°C, in order to preserve them. In spite of the fact that foods are only heated for a few minutes at a time, this process inactivates certain enzymes and destroys most microorganisms, preventing spoilage and preserving many important nutrients.

In contrast, freezing removes heat from the food. This slows down the chemical reactions in food by lowering its temperature (around -20°C), preventing important nutrients from being lost. Blanching foods before freezing is also common practice. As a result, the natural enzymes in the foods are inactivated, preventing further loss of nutrients.

There is an inevitable loss of nutrients during thermal processing, such as canning and blanching. However, the extent of this loss varies with the nutrients in the foods. Canning generally results in a greater loss of nutrients than blanching or freezing. Most fruits and vegetables must be boiled in water before being sealed due to higher temperatures and harsher processing conditions.

When carrots are frozen, for example, very little vitamin C is lost. Since vitamin C is a water-soluble vitamin, it is easily broken down by the water, especially after being degraded by heat during canning. Since vitamin A is more stable against heat, it loses much less during canning. During freezing, more vitamin A is lost.

The importance of nutrients: Despite the loss of some nutrients during blanching, freezing, and canning, in many cases, the foods retain more important nutrients than they would if picked just before peak ripeness and shipped to their destination supermarket. Frozen blueberries, for instance, have a similar vitamin content to fresh blueberries and sometimes even higher.

Even after three months in storage, tinned peaches retain virtually all their nutrients despite losing some nutrients during canning. Even after a year in storage, canned and frozen products such as peas, sweetcorn, and broccoli retain many of their nutrients. Foods also contain other compounds. The polyphenols found in most fruits and vegetables, some of which have been linked to better heart health, can be preserved by freezing for longer periods of time.

Although frozen or tinned produce may contain different nutrients than fresh produce, there is no significant difference between the two. In canned tomatoes, lycopene, the compound that gives tomatoes their red color, is actually higher than in fresh tomatoes. The high temperatures used during canning help release more lycopene. As canned tomatoes are linked to a lower risk of cardiovascular diseases, people might consider buying canned tomatoes instead or canned, fresh tomatoes themselves.

Many of the nutritional benefits of fresh produce can be found in frozen or canned fruits and vegetables. With the current food shortages, they can be a more accessible and longer-lasting option.