I was wondering what nutrition is lost when you store milk in different ways. Does frozen milk have the same antibodies as the milk stored in the fridge and the milk stored at room temperature? It also depends on the storage container type.
http://www.askdrsears.com/html/2/T026900...
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What kind to use comes down to two issues:
* protecting the milk and all its valuable components
* your convenience and that of the baby's caregivers.
Unfortunately, there is not a lot of research about how storage containers affect human milk. One study showed that the leukocytes in milk (the live cells that transfer immunity from you to your baby) sticks to the side of glass containers, but subsequent research showed greater numbers of leukocytes in glass containers than in plastic, as the cells were released from the sides of the containers over time. Research has also shown a loss of antibodies and fat in milk that is stored in plastic bags, but this information applies only to disposable plastic nurser bags, the thin ones you can buy at most stores to use with baby bottles. If you do choose to store your milk in these, use two bags to protect against breakage and "freezer burn." Use twist ties to close the bags.
Plastic bags specially designed for freezing expressed human milk are available from many companies that specialize in products for breastfeeding mothers and babies. These bags are sturdier than those used in baby bottles and have self-closures that are easier to seal and label. They do a better job of protecting milk components than nurser bags. Some types can be attached directly to your pump. Plastic storage bags are available from The LLLI Catalog.
The information currently available suggests that glass or hard-sided plastic containers (the kind of plastic that is clear, not cloudy) provide the best protection for nutrients and immunities. Hard containers should have secure, one-piece tops. If your baby is getting a lot of his nourishment directly at the breast, you don't need to be as concerned about nutrient loss through freezing and contact with storage containers as you do if your baby is getting only expressed milk and not nursing directly at the breast.
Convenience is another issue, and opinions will vary. Plastic bags take up less room in the freezer and are one-use items, so there's no dishwashing involved. However, filling them and pouring milk out of them can be awkward.
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Freezer or refrigerator? How quickly does human milk spoil?
Freezing destroys some of the immune properties in human milk, so it's best if your baby is given fresh milk--milk that has been expressed and then refrigerated. The chart in Storage Times for Human Milk tells you how long you can keep expressed milk at room temperature, in the refrigerator, or in the freezer. (Print this file and keep it on your refrigerator door!)
Label each container with the date, so that you can use the oldest milk first and avoid needless waste.
http://www.breastfeed-essentials.com/sto...
When a baby is only receiving expressed milk occasionally, the type of storage container is not a major consideration; however, if a baby is receiving most of his nourishment from expressed breastmilk, the type of storage container used should be considered carefully. Plastic containers are the best choice for storing breastmilk in the refrigerator as more of human milk's leukocytes or white cells adhere to glass. If the milk is to be frozen, glass is the preferred choice as it is less porous and offers the best protection. Most of the leukocytes in human milk are killed with freezing anyway. For this reason, milk that can be used within 8 days of expression should be refrigerated rather than frozen, because the antimicrobial properties of human milk are better preserved with refrigeration.
Another good choice for refrigeration or freezing is the milk storage bags that are designed specifically for human milk (see CSF milkbags). They are pre-sterilized and are thicker (2-ply), coated with polyethylene, and lined with nylon which prevents the fat from adhering to the sides. Hard plastic containers of any kind are also good choices for both refrigeration and freezing. Other milkbags, sold specifically as bottle liners, are not as durable, making them an unacceptable alternative when freezing the milk as the seams may burst during the freezing process perhaps causing a leak during thawing. Also, one study found that there was a 60% decrease in the milk's antibodies and a loss of fat that adhered to the sides of these bags. If this type of bag is still chosen, the milk can be better protected by placing the liner bags in a larger gallon size freezer bag or in a hard plastic container.
When milk freezes it expands, so it is necessary to leave about an inch at the top of the container to allow for expansion. For this reason, bottle caps or container lids should not be tightened until the milk is completely frozen.
http://www.mother-2-mother.com/storemilk...
When freezing your milk, there are several things to take into consideration. The type of container chosen may be important if the bulk of your baby's milk is frozen milk. In that case, freezing in glass is best because it is less porous and offers the best protection in the freezer. If the frozen milk is for occasional bottles, the type of container is not as important. Also keep in mind that freezing does destroy most of the leukocytes, so whenever possible the bulk of baby's expressed breastmilk should be "fresh" vs frozen.
http://parenting.ivillage.com/newborn/nb...
Is There a Nutritional Difference?
In regard to the differences between breastmilk provided by breastfeeding and expressed breastmilk, we have learned through research that some of the immune components, vitamins and fat may be lost during the storage and handling of expressed milk. (Lawrence 1994) (Arnold 1999)
I want to strongly stress that even with these losses, expressed breastmilk is much better for your baby than formula. With breastmilk, like any food, fresh is best, second to that would be refrigerated and frozen would be the next choice, though again still vastly superior to formula. To compensate for the loss of some of the components through storage and the changes that occur in the composition of breastmilk related to the age of the baby and time of day, it鈥檚 a good idea to try to provide some freshly-pumped milk as often as it is reasonable.
When a baby is nursing from the breast there can be enhanced immune response. Mothers will also start to produce specific antibodies to illnesses when exposed directly to a germ, so if there is a cold or other minor infectious illness going through your family it might boost your baby鈥檚 protection to provide more freshly pumped milk at that time.
While pumped breastmilk, provided by bottle, is not exactly the same as breastmilk directly taken through breastfeeding, it is certainly as close to breastfeeding as one can get. Breastfeeding is always considered the number one choice for all infants, with mother鈥檚 own expressed milk as a very close second choice. Banked breastmilk (though not widely available) would be the third choice, with formula coming in a distant fourth.
http://www.sciencedirect.com/science?_ob...
Vitamins C and E and fatty acid levels in human milk were determined when fresh, after refrigeration at 4 掳C for 96 h, and after freezing at 鈭?0 掳C or 鈭?0 掳C for 12 months. Total vitamin C content at 4 掳C (6 h), 鈭?0 掳C (8 months) and 鈭?0 掳C (12 months) was significantly decreased. Vitamin E levels did not change at either refrigeration temperature (under 24 h) or at freezing or ultrafreezing temperatures. Our analysis revealed that fatty acids are not affected by cold storage. In conclusion, we recommend a change in milk storage practices; specifically, it should be stored up to 3 h in a refrigerator, up to 5 months in a freezer or up to 8 months in an ultrafreezer (鈭?0 掳C). Alternatively, vitamin C supplementation may be considered. In addition, we propose vitamin C as a marker for human milk stability.
http://www.jpgn.org/pt/re/jpgn/abstract....
This study analyzed the bactericidal activity of human milk and how it is influenced by refrigerated storage. Nine samples of mature human milk were collected and divided into 3 aliquots. One was analyzed immediately, and the other 2 were refrigerated at 4[degrees]C to 6[degrees]C for 48 and 72 hours, respectively. All of the fresh samples exhibited bactericidal activity with an average value of 83.47% +/- 18.37%. Refrigeration for 48 hours did not cause significant modifications, whereas storage beyond 72 hours significantly lowered the degree of bacteriolysis versus fresh milk. In conclusion, human milk possesses bactericidal activity that remains stable during the first 48 hours of refrigerated storage, but it is significantly reduced beyond 72 hours. True it's best straight from the "tap" or straight from breast to cup/bottle, but very little nutritional benefit is lost from refrigerating or freezing breast milk. Now it can loose it's antibodies and nutritional benefits if you microwave breast milk. You want to warm it in a cup of warm/hot water until it becomes room temperature or slightly warmer. Make sure to always test it before you feed your baby to make sure it's not too warm. At room temperature breast milk is good for about 4 hours, in the fridge about 3-5 days, and in the freezer for about 3 months. I think the nutrients stay pretty similar in each storage situation. The way nutrition is lost, from what I've heard, is if you warm expressed breast milk in the microwave.
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