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During the quarantine period, many stock up on food, freezing meat, vegetables or convenience foods. This method of storage is a real salvation: fast, convenient, affordable. But doubts about the nutritional value of such products still exist. Are they worthy of becoming the basis of our menu, or is it better to resort to them only when necessary?
A variety of perfectly stored, quick-cooking frozen foods make life easier. However, in our minds, it is difficult to associate them with a healthy diet. However, many studies show that they are rich in vitamins and nutrients – almost like fresh foods.
“Freeze” and “quick freeze”
There is indeed a difference between these concepts. The so-called shock freezing, a method used in the industrial production of food, involves instant freezing at a very low temperature, from -20 ° C to -40 ° C. This method ensures high quality products.
For example, if vegetables and fruits grown outdoors and harvested at the peak of their ripeness are frozen, they will be more useful than “fresh” fruits that have been stored for a long time, which are often harvested ahead of time so that they can better withstand transportation.
Freshly caught fish that is frozen directly on the ship has another advantage: it is harvested from the open sea and often tastes better than chilled fish from pond farms.
Deep (shock) freezing products can be stored for a long time – up to one and a half years, but at the same low temperature. When these products migrated from industrial refrigerators to home ones, they are best consumed within a month.
You can freeze vegetables and fruits on your own, in a household freezer, but they are stored much less – 4-6 months. Freezing meat or fish at home is not recommended, they cannot be stored for a long time.
Even short-term freezing for 24 hours kills most parasites. This circumstance can be used by lovers of sashimi, fish and meat carpaccio and other dishes from raw products. However, this method only slows down the reproduction of microorganisms, without completely eliminating the risk of poisoning.
Who is not afraid of frost
If we compare different methods of preservation, then freezing is the most preferable from the point of view of the safety of biologically active substances.
Vitamin C, folic acid, bioflavonoids are almost completely lost during any other processing, and are preserved when frozen.
Oily fish such as salmon or halibut, rich in omega-type polyunsaturated fatty acids, tolerate quick freezing best. Most natural antioxidants tolerate cold much better than heat: they are destroyed at temperatures above 40 ° C.
Flavour and Fragrance
This is the problem that frozen food producers face: it is difficult to keep their natural taste. In addition, most berries, fruits and vegetables lose their flavor. Only dense foods containing relatively little water (chicken, eggplant, root vegetables, mushrooms) can almost completely retain their taste.
Trying to make frozen foods more attractive to the consumer, manufacturers use flavoring additives to create semi-finished products: frozen cutlets and meatballs, pies, lasagna, risotto, and various casseroles.
Such products contain too much salt, fat or sugar – it is better to give preference not to semi-finished products, but to natural fresh-frozen products, be it fish, meat or vegetables.
Proper defrosting
The method of defrosting also greatly affects the preservation of taste and aroma. As a result of freezing, the moisture contained in the products turns into ice crystals. With rapid defrosting, ice crystals begin to break the walls of cells, capillaries, fibers, and the product loses useful juice, water-soluble proteins, carbohydrates, and minerals leave with it.
For example, meat, as a result of rapid defrosting, loses iron, and berries and fruits lose pectin and water-soluble vitamins. The most correct and gentle way to defrost is slow.
The meat can be transferred from the freezer to the refrigerator and cooked for the next day. Fish is best thawed in cold water. Berries and fruits are best subjected to slow defrosting if you are not going to cook them. Or throw them into the pan (into the pan) immediately, without defrosting.
While many people don’t associate microwaves with healthy eating, research shows that microwave defrosting causes the least loss of vitamins. It takes only 8-10 minutes to defrost, and there is no such large loss of liquid as with conventional defrosting. As for other aspects of the effect of this energy on the nutritional properties of foods, they have yet to be studied.
Cold factor
Quick-frozen foods require certain conditions to be truly useful in the diet.
No food should be re-frozen: there is a risk of contamination with pathogenic microorganisms. Moreover, microbes are preserved during the freezing process, and after defrosting they are active and begin to produce various toxins, which is fraught with poisoning, especially for meat and fish.
For transportation after purchase, it is worth using insulated bags – they can be found in the supermarket near the shelves with frozen foods.
Defrost your freezer regularly: this preventive measure helps preserve the natural fresh smell of food.
If frozen food has been thawed for some reason (for example, due to electrical problems), they must be moved from the freezer to the main compartment of the refrigerator and consumed within three days.
About the experts:
- Ludmila Shatnyuk – Head of the Laboratory of Technology of New Products of the Institute of Nutrition of the Russian Academy of Medical Sciences;
- Daniel Kiefer – French naturopathic doctor;
- Jean-Michel Cohen is a French nutritionist.