Frozen raspberries: benefits and processing features
Everyone knows about the benefits of fresh berries and fruits. The fact that during the heat treatment they lose most of the vitamins and minerals is also known to many. And how useful a frozen crop, in particular, raspberries, will be discussed in this article.
Properties
Raspberries are rich in potassium, which provides strength and endurance of the body, acting as a natural antidepressant. The high content of vitamins A and C allows us to talk about the antioxidant and anti-aging effect of berries. It is important that frozen raspberries retain almost all trace elements and vitamins.
The fresh product is characterized by a low glycemic index, does not cause large spikes in blood sugar and provides a long-lasting feeling of satiety. The calorie content of frozen berries is 1.5 times lower than fresh ones. There are only 31 kcal per 100 grams of frozen product.
With proper freezing, most of the vitamins are preserved in the berries, including up to 95% of the “capricious” and unstable to processing vitamin C. For comparison, in dry raspberries it is only 30%.
In a frozen berry, the content of vitamin B1 (thiamine) is reduced by 25% and vitamin B2 (riboflavin) is reduced by 4-18%.
The iron and copper contained in fresh fruits are also resistant to high-temperature processing, so the frozen analogue can be used to maintain hemoglobin levels. Fiber helps to improve intestinal motility, so raspberries in any form can be used as a mild laxative of natural origin.
Harm to health is caused by excessive consumption of raspberries. Refuse it should be people with individual intolerance. In the presence of diseases such as stomach ulcers, kidney disease, gout, you should reduce the consumption of berries and refuse to eat them in the acute period of the disease.
Finally, we must not forget that red berries are a strong allergen, so they should be given to children with caution.
It is fair to speak about the benefits of frozen raspberries only if the following criteria are met:
- place of growth;
- assembly time;
- freezing technique.
The greatest benefit will bring a berry grown in natural conditions (preferably with your own hands), harvested in season, being ripe and properly frozen.
Raspberries sold in supermarkets are usually imported or greenhouse. The content of useful components in it is minimal, but in excess of dyes, various chemicals. The latter are used to improve the appearance and density of the berry, and to extend the shelf life.
The imported product is usually collected unripe, otherwise it will simply spoil during the transportation process. Berries ripen already in warehouses and shop windows, being treated with special compounds. It is also not necessary to talk about the positive effect of the composition on the body.
Freezing methods
The technology of freezing berries is another important factor influencing their usefulness. The optimum storage temperature is -18 ... -24C. In this mode, raspberries are stored for up to a year without losing their taste and nutritional qualities.
However, it should be remembered that the longer the storage of raspberries, the more it loses vitamins. It is better to store a small batch of berries for no longer than 3-4 months, while a temperature of -8 ... -10C is sufficient.
An important condition for the preservation of vitamins in a frozen product is the absence of defrosting and re-freezing. Such a product not only turns into an unappetizing gruel, but also completely loses useful components. Eating store-bought frozen berries, from this point of view, is of dubious benefit - the probability of violating raspberry storage technology is too high.
Depending on the purpose and method of eating berries, raspberries can be frozen whole or mashed. In the first case, more space in the freezer will be required for storage, the grated mixture is much more compact.
Pureed compositions are usually used in the future for the preparation of jams, preserves, compotes, as a filling for baking. In this case, it is logical to immediately put sugar or its substitute in them.
Ripe and even slightly unripe berries are suitable for freezing. Crumpled and let juice is better to eat or cook jam, compote.
Berries can not be washed if you are sure they are clean. Experienced housewives prefer to pour berries for a few minutes with cool water. They will sink to the bottom, and litter, insect larvae, will float to the surface. After that, it remains only to carefully remove the clean raspberries and sprinkle them in one layer on a towel to dry. You can speed up this process by blotting the top of the product with a paper towel.
When purposefully harvesting for freezing, it is better not to put it in a bucket or basket, but to collect it on a tray. It is then placed in the freezer, which allows you to maintain the integrity and structure of the berries. After 15-20 minutes, the tray can be taken out of the freezer, and the berries can be poured into a plastic bag or a special container and freezing can be continued.
Pre-freezing will avoid sticking of berries, with subsequent defrosting they will have an attractive appearance.
If the aesthetic component is unimportant, you can skip the pre-freezing stage and immediately pack the raspberries in plastic bags of 200-250 g each. The bag should be tied up, leaving a little air in it, and then placed in the freezer.
It is convenient to freeze large volumes of raspberries in rectangular plastic containers - they are ergonomically located in the "freezer" chamber. However, the purchase of such containers is an additional expense that can be avoided. It is enough to purchase one container and put a plastic bag inside it. Raspberries are poured into it, after which the container is removed into the “freezer” for 30-35 minutes.
After the specified time, you need to get the container and remove the bag with berries from it. It will have a convenient rectangular shape for storage. The package is sent to the freezer, and the container is again lined with cellophane and filled with berries.
There are the following main types of freezing berries:
- whole fruits without sugar or with sugar;
- whole and pureed berries, frozen in layers;
- raspberry puree with or without sugar.
To freeze raspberry puree with whole berries, first, a layer of whole fruits is poured in one row. The next layer is raspberries crushed in puree (it is better to select overripe fruits). Sugar is added to puree.
Puree with or without sugar (in the latter case, the composition can be used for cosmetic purposes) is poured into small containers with a lid. You can adapt curly molds for this. The resulting puree will appeal to children.
The technology for freezing whole berries (with preliminary low-temperature exposure) has already been described above.If you need to get whole berries with sugar, then pre-frozen raspberries are laid out in a plastic container, on top - a layer of granulated sugar, then another layer of raspberries and so on.
Features of use
The defrosting of berries is carried out on the middle shelf of the refrigerator or using a microwave oven.
If raspberries are intended for making jam or jam, then it can not be thawed, but immediately subjected to heat treatment. If you decide to make a pie with raspberry filling, then it is better to defrost the frozen composition and remove excess liquid. Otherwise, it can change the texture of the dish for the worse.
Frozen raspberries can be used to make compote, fruit drink, jelly and juice. Raspberry juice is an effective method of combating anemia due to the high content of copper and iron in it, as well as its excellent prevention. Rich in vitamin A, as well as potassium and folic acid salts, raspberry juice is indicated for atherosclerosis, joint diseases. The record content of ascorbic acid makes the juice a reliable assistant in the fight against influenza, SARS and colds.
The recipe for this healing drink is extremely simple: raspberries or puree should be thawed and rubbed through a sieve. Sugar is added to taste. If the drink seems too concentrated, you can dilute it with water.
An important point - juice should be prepared immediately before use. It is not intended for long term storage.
Raspberry compote is also easy to prepare. An ice cream mixture is added to boiling water, the sweetness of the drink is adjusted. Kissel is cooked in a similar way, however, starch must also be added here.
Raspberry tincture will not only be a delicious drink for the festive table, but also warm with hypothermia, cold chills.To do this, you can mix 3.5 kg of thawed whole raspberries or puree with 1 liter of vodka or cognac. In the resulting composition, you need to add sugar syrup (boil 250 g of sugar with the same volume of water until a caramel shade). Insist 3 weeks, filter.
From frozen raw materials, you can cook jam. To do this, the thawed berry is covered with sugar from a ratio of 1.2 kg of sugar per 1 kg of berries. After that, the composition is aged for 6-8 hours, periodically it requires mixing. Next, the mixture is cooked in 3 sets of 5 minutes with breaks of 6 hours between each "five minutes".
Healthy and tasty marmalade can be made from raspberry puree. It is better to grind it again through a sieve after defrosting to remove the bones. It remains to add gelatin or agar-agar diluted in water to it, mix thoroughly and pour into molds.
Whole or pureed berries can be added to tea. The addition of medicinal herbs or raspberry leaves will increase the beneficial effect of such a drink. Dry the latter in the fall in natural conditions.
How to freeze raspberries, see the following video.