Question: “We freeze fruits and vegetables each year, because we grow them by ourselves, although we generally do mental work. Thus, we know what we eat and we have enough for children and grandchildren. But the young make remarks we should vacuum each package, remove the fruit stones in advance, cut the fruits to pieces etc. Recently, they learned it is harmful if there is air inside the package and this is even worse than if the washed fruits and vegetables are not dried and thus surrounded by ice practically. Their beneficial ingredients are kept better in this way. I don’t find sense in this, but I’m not a specialist, so let the people who work nutrition say which is the best way to freeze the garden production? For how long it can stay and are there any of the sterilized fruits and vegetables which are more beneficial than the raw ones?”
The organisms, invisible for the human eye, are everywhere around us and many of them help us with their life activity, but others unfortunately harm us. All foods contain microorganisms which are the main reason for food spoiling. Freezing is the most contemporary and efficacious way for food preservation.
The food is frozen at different temperatures. For fruits and vegetables this temperature is around -30oC to -40oC, and for meat from -20oC to -40oC. Frozen products keep the dietetic, nutritional and organoleptic properties of the raw materials to large extend. Thanks to this method, products preserve most of their nutritional ingredients, compared to all the other known ways of preservation, including the so valuable for the organism vitamins, minerals, proteins and fats. Once unfrozen, the food should not be frozen again. It is also good to know that freezing does not have the effect of sterilization, as it does not kill the microflora but only stops its development. Sometimes the nutritional value of frozen fruits and vegetables is larger than that of the fresh ones because the time from harvesting to freezing is maximally short – only several hours. Even if they are gathered in the best time for harvesting, the products lose vitamins and minerals on their way to the market, as they use them for their own metabolism. Green beans could be an example for this, as they lose 40% of vitamin C in 24 hours from the time of collection. The other vegetables and fruits are also subjects to such processes.
The main principles in freezing fruits and vegetables are:
1. Mature and undamaged products are chosen. They are cleaned, washed and eventually blanched (blanching stops the action of enzymes which otherwise would spoil the outlook and taste of the vegetables). After taking them out of the water, vegetables are quickly flooded with cold water or left in a bowl immersed in ice water. They are packed and frozen after complete cooling.
2. The water is drained carefully. Fruits and vegetables must be perfectly dry.
3. Freezing packages should be thick and should not burst at low temperatures.
4. It is appropriate to mark the packages (date of freezing) and to put them in the freezer at suitable temperature.
The proper packaging of products is particularly important in freezing. If the package is damaged, foods dehydrate, fats become rancid, which leads to taste worsening and formation of harmful substances. Evacuating the air during vacuuming slows down additionally the loss of taste and food spoilage. The products we buy always have a shell life. And the foods frozen at home have the following durability:
-1 to 2 months: pastry, dough, fat fish, meat and chicken in sauce, mince and sausages.
-3 to 4 months: lean fish, cheese, boiled meat and vegetables, soups.
-6 to 8 months: butter, seafood, mussels, cupcakes, tomatoes, mushrooms, melons, pears, plums.
-8 to 10 months: mutton, veal, red berries, apples.
-around 12 months: beef, chicken, green beans, carrots, celery, turnip, peas, squash, eggplants, cabbage, spinach.
If we compare freezing with the other types of storage of fruits and vegetables, for sure it is superior to the traditional preservation. No matter how much tenderness the grandma’s jars cause in us, they have almost no vitamins left. The reason for this is heat treatment and adding preservatives. It is true we cook the vegetables after unfreezing them, but for boiling we need only several minutes which maximally keep the valuable substances.