What determines the shelf life
How to properly store milk is not an idle question, because its quality depends on it. At the same time, proper storage is not a complicated science. It is important to answer three questions:
- what type of processing the product was subjected to;
- what container it is packed in;
- under what conditions should it be stored?
During production, “cow drink” is subjected to various types of heat treatment. It is necessary to protect milk from bacterial and fungal microflora, which actively multiply in unprocessed dairy products, reducing their shelf life and leading to souring. According to the type of processing, milk is:
- Ultra-pasteurized. This is a modern approach to processing. Pasteurization is carried out at t=+145°C, and then the milk is quickly cooled. This is a shelf-stable product that maintains quality.
- Sterilized. The processing technology takes place at t=+115°C. This is enough to destroy microorganisms. At home, this process is called boiling.
- Pasteurized. Processed at temperatures below +100°C. Disinfection depends on antiseptic packaging. This is the most valuable product that retains its beneficial qualities as much as possible.
How long milk can be stored depends on the consumer container in which it is packaged. Various containers for storing milk have been invented:
- glass: ideal, but most impractical container;
- tetrapack: “milk drink” can be stored without refrigeration until opening;
- PET bottle: transparent, so it cannot be left in the sun; over time it acquires a slight taste of plastic;
- polypak or thick plastic bag: it retains the taste well, but is not entirely convenient to use.
Regardless of the processing method and container used, the milk product should be stored in a cool place or refrigerator. This significantly extends shelf life.
The importance of safe meat storage
Safe storage can protect meat from loss of quality and flavor, as well as bacterial growth.
The United States Department of Agriculture (USDA) notes that storing meat safely in a freezer at -18°C lowers the temperature to a point that inhibits the growth of most bacteria ().
Higher temperatures can allow bacteria to grow on the meat, which can cause illness. This is why meat usually only lasts for a few days in the refrigerator. Cooler temperatures may slow the growth of some bacteria, but this is not enough to prevent food from spoiling.
Proper freezing also protects against pathogenic bacteria that cause foodborne illness and food poisoning ().
Reliable storage also protects meat from loss of taste and quality. A number of compounds in meat oxidize and break down fairly quickly at room temperature, which can lead to a noticeable loss of flavor.
Proper storage methods such as drying, smoking and freezing can help slow this process or prevent partial or complete loss of quality.
How to prolong the freshness of milk
The packaging indicates a specific expiration date for cow's milk prepared using the “conveyor method”. To extend it means to violate the storage rules. The manufacturer independently regulates the time, which depends not only on the processing methods, but also on the introduction of thickeners, preservatives and stabilizers into the drink. Then he approves all indicators in Rospotrebnadzor.
As for natural milk, it can be stored for a day in the refrigerator. This is a very short period of time, during which the owner does not always have time to use it. The shelf life is extended by boiling or freezing.
The boiling method has one important point: the milk must be brought to a boil, but not boiled. This will allow you to preserve the useful composition as much as possible and extend the storage time. Another way to store fresh milk for a long time is freezing. Frozen “cow drink” can be stored for up to 2 months.
Often, when boiling, milk “runs away”, overflowing. To avoid this, you need to place an inverted saucer on the bottom of the pan. Another option is to use a “milk guard” (a ribbed circle with a spout).
Composition of milk
Despite the fact that the composition of milk may have different characteristics, depending on the health of the animal, its diet, and, of course, the breed, the general type of composition is still there. The product is enriched with calcium, magnesium, fluorine, potassium, phosphorus, iron, iodine and other macro and microelements, vitamins D, B1, B12, B2, A. About 86% of milk consists of water. The remaining 14% comes from proteins, minerals, milk sugars and milk fats.
And the calorie content of milk per 100 grams ranges from 25 to 85 kcal, depending on the processing method and the original composition.
Is it possible to freeze milk?
It is possible to freeze milk, but this destroys some enzymes and vitamins, and the product loses its original qualities. This technique is justified if long-term storage is really necessary.
Freeze milk in the freezer
Freezing is carried out in two stages:
- Milk is poured into a plastic container, not filling it to the brim. Any liquid product takes up more volume when cooled.
- The container with milk is placed in a freezer with a temperature down to -22°C to make freezing faster.
Frozen milk can be stored for about 2 months. After which you can safely drink it. This period can be shortened or increased if desired.
How to defrost milk correctly
Defrost milk on the bottom shelf of the refrigerator. Simply rearrange the container in the morning, and in the evening you can use the milk drink. It will not be similar to the original one in its organoleptic characteristics. A defrosted drink will change color, taste and consistency. It cannot be frozen again, since the last signs reminiscent of primordial milk will disappear.
Milk is a popular grocery product. I use it in my daily diet, with rare exceptions, for everything from small to large. The taste and beneficial properties will remain unchanged if you follow three basic rules: put the product in the refrigerator on time, check the manufacturing date on the packaging and store for the required period of time.
Author of the article: Irina Borodina
Education: Higher education, Tomsk State Research University named after Kuibyshev, 1988, biologist with the right to teach biology and chemistry. Specialization: botany, biochemistry. Work experience: correspondent, proofreader; and about. director of vocational lyceum No. 37; teacher of chemistry, biology at school and lyceum, highest qualification category. 20 years of teaching experience; Researcher at the Laboratory of Plant Physiology and Biotechnology; Senior Researcher at the Laboratory of Biochemistry of the OPH named after. Sidorenko.
How to store and for how long?
The shelf life of milk depends on :
- heat treatment method;
- packaging;
- storage temperature.
Milk in soft packaging has the shortest shelf life. The product is stored longest in cardboard bags; they are opaque and protect the liquid from light.
If you want to increase the shelf life of milk, you can boil it or freeze it.
Boiling extends the life of the product by 4 days, but deprives it of almost all beneficial properties. Boiled milk is stored in the refrigerator in a closed enamel container.
There is no need to boil store-bought milk for greater safety . At the factory, the liquid has already undergone heat treatment.
Find out what GOST tells you about storing sour cream here.
You can freeze both homemade and store-bought milk. The advantage of freezing is that the frozen product does not lose its beneficial properties.
It is better to pour milk for freezing into small plastic bottles . You need to pour so that there is room left in the bottle; when frozen, the liquid increases in volume.
Another good way is to freeze milk in ice cube trays. The shelf life of the product in the freezer increases to 6 weeks .
Unopened milk is stored in cool, dark places.
Opened milk packages should be stored in the refrigerator, regardless of the type of heat treatment.
Powdered milk can be skimmed or whole, and what is obtained when the powder is dissolved in water is called reconstituted milk .
Skim milk powder has a better shelf life than whole milk. Under no circumstances should you keep it in the heat - it will quickly disappear.
How long ice cream can be stored and under what conditions, read here.
At home, this powder can be stored in an open state for about a month . After dilution, it is better not to keep it in the refrigerator for more than three days.
coconut milk is stored for no more than 2 days in the refrigerator, at fairly low temperatures - from 2 to 5 degrees.
If you freeze it , the shelf life is extended to 2 months.
Find out how and for how long you can store cottage cheese here.
How to preserve breast milk
Not everyone knows whether it is possible to store expressed milk in the refrigerator or under other conditions. As it turns out, there are several ways to preserve breast milk for your baby, each of which has its own deadlines.
Storage at room temperature
How to properly store expressed breast milk depends on how long the storage is planned for. Scientists have long proven that even at room temperature, human breast milk can be stored for a certain period of time without problems. For 2-6 hours you don’t have to worry about the product at all, it will be of excellent quality. In order for the baby to eat with appetite and not have further problems, it is necessary to follow these rules:
- pumping is carried out in a sterilized container;
- should be stored away from sunlight in a plastic or glass container;
- heating appliances and other food should not be nearby;
- The container must be tightly closed.
After the specified period of time, the product will gradually begin to deteriorate; it should not be given to a child. Do not store in the refrigerator or freeze. The best thing to do would be to just pour it out, even though this product is very valuable.
Important! Shelf life without refrigeration is significantly reduced if the room with the product is hot. If the thermometer readings are above +20, the product will begin to deteriorate within a couple of hours.
How to store breast milk in the refrigerator
The shelf life of breast milk in the refrigerator is much longer than at room temperature. But there are many different nuances here too. How many hours it is possible to preserve milk expressed by a mother without harm to the baby depends on where to place the container with the product.
Milk can be stored in the refrigerator for different periods of time in compliance with all the rules:
- How long can you store expressed breast milk in the refrigerator door? In this place, the product will not deteriorate for 4-5 hours, and it will not have time to cool much. This option is used mainly in the summer; it will retain all the vitamins and nutrients until the next feeding.
- How long can breast milk be stored in the refrigerator on the bottom shelf? This place is considered ideal for the product; if pumping is done correctly and containers are selected, nothing will happen to it for a week. But experts do not recommend storing the product for so long; it is advisable to use it within 4 days.
- How long does expressed breast milk last in the refrigerator on the top shelf? It is not recommended to preserve it under such conditions, unless it is offered to the baby for a maximum of 24 hours. Longer storage periods will promote the development of pathogenic bacteria even in sterile and closed containers.
It is worth understanding that for a baby the best option is a fresh portion from the breast, and not a previously prepared portion from a bottle. Even if you adhere to all the rules and regulations when expressing and storing, fresh milk is healthier for your baby.
How long can breast milk be stored in the freezer?
We found out how long breast milk can be stored at room temperature and in the refrigerator. But another method of preserving the product is freezing; in the freezer, the shelf life of breast milk increases to 9 months. It is important to freeze the product correctly, and then defrost the product correctly. The storage rules are as follows:
- Only freshly expressed milk is frozen at home;
- It is worth carrying out the procedure by dividing the product into small portions of 60-120 g;
- the container must be sterile and tightly closed;
- It is best to use special bags or bottles that come with the breast pump.
It is strictly prohibited to freeze a product that was previously stored under other conditions, including in the refrigerator.
Frozen breast milk must undergo proper defrosting before consumption. Then all the beneficial substances will be preserved as much as possible, and the baby will receive everything he needs with food.
Important! Thawing breast milk at room temperature is unacceptable; a sharp change will negatively affect the quality of the product.
The product is defrosted at least a day before use, while the process itself takes place in the refrigerator in a bottle or other container in which it was frozen.
How long does breast milk last after defrosting? The shelf life of the product is very limited, only a couple of hours. Afterwards, the product must be thrown away, otherwise it is fraught with consequences.
Other ways to save
For many, it is unclear how such an important product can still be preserved. But methods do exist; it is important to know how long a given product can be stored. Different methods will vary in terms of timing:
- expressed milk at room temperature can be stored in warm water if feeding takes place over an hour; longer periods are not advisable for this method;
- store the product in a cooler bag with frozen elements, this method will prevent the product from spoiling for 2 days;
- If the air temperature is high and there is no refrigerator, the product in the bottle can be placed in cold water.
It is not recommended to apply ice if it is to be consumed in the near future.
