Preservation by frost: how to maintain the utility?
However, in order to obtainReally useful and nutritious product, it is necessary to follow the rules of freezing. And there are a lot of them. The main ones concern the speed of the process of primary freezing, proper packaging (tare), maintenance of the desired temperature and storage time.
The best quality will be those vegetables andFruits that will be frozen as quickly as possible. In the factory, the "shock method" is most often used for this, when the product immediately after collection, purification and drying drastically cool down to -40 degrees Celsius. This avoids the formation in the cell structure of the fruits of large ice crystals, which can form at temperatures from 0 to -5 degrees. Thus, the consistency of the products remains the most, and the loss of vitamin C is minimal. At home, it is not always possible to provide such a speed, and therefore the quality of domestic harvesting is slightly lower.
It is very important to choose the packaging sufficientDensity. If this is a packet of food polyethylene, then as much as possible squeezes out excess air, providing sufficient tightness. In addition, it also allows you to keep in fruits ascorbic acid, which is simply deactivated with a slow increase in temperature in the presence of oxygen.
The optimum storage temperature is about-18 degrees Celsius and below. Under such conditions, there is no significant change in protein and fat content, and an almost complete quantity of pectin, micro- and macro elements is almost completely preserved. Too low temperature somewhat suppresses the activity of enzymes and can sometimes cause damage to their complex structures, and too high a high probability of the acceleration of chlorophyll. And this means that both, as a result, will lead to a change in flavor, color and taste.
Particular attention should be given to the shelf life. Do not save vegetables and fruits for longer than six months, a maximum - a year. Perhaps, taste quality will change not so noticeably, but the usefulness of long-term storage of fruits will not be added. Especially, if during storage there were even insignificant temperature fluctuations.
Freeze only the freshest and healthiestfruit. Use a convenient, small packing. This will make it possible to easily separate the desired portion, quick-freeze the product and not break the storage conditions of the rest.
Remember that re-freezing is not allowed. After all, the nutritional value is not only disturbed, but all the qualitative characteristics of the product also suffer.
Observe these simple rules, and frost will save for you a useful, tasty and fragrant slice of summer.