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Author Topic: Can shaking break down the amino acids in breastmilk?  (Read 7130 times)

Offline Saartjie

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When you express breastmilk, it settles out into a cream layer and a milk layer quite quickly. The quickest way to mix it up again before you give it in a bottle to baby is to give the bottle a good shake. But many people hold that doing this damages the milk, both by breaking down the amino acids in the milk, and killing the cells in the milk (this is the reference I am going from: newbielink:http://www.bflrc.com/ljs/breastfeeding/shakenot.htm [nonactive]). I don't have enough background in biology to know if this makes sense or not, but it sounds a bit iffy (and so much advice mothers are given is not based on evidence that my instinct is to question everything). Anyone able to shed some light on this?


 

Offline chiralSPO

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Re: Can shaking break down the amino acids in breastmilk?
« Reply #1 on: 23/05/2014 12:24:31 »
I don't think shaking would actually break down proteins (and is very unlikely to actually break down the amino acids themselves)--covalent bonds are very strong. However, it is entirely believable that vigorous shaking could denature the proteins (change how they are folded--I believe this process is responsible for the change in consistency of egg whites after being whipped). I don't know to what extent the proteins are expected to be active components in breastmilk, or if they all just get digested very quickly (stomach acid denatures many proteins very quickly)
 

Offline Saartjie

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Re: Can shaking break down the amino acids in breastmilk?
« Reply #2 on: 23/05/2014 12:55:39 »
cool - thanks for the response! My quick consultation of google suggests the denaturing of proteins is a big part of what is happening when food is cooked. Its also occurred to me that violent agitation of milk is how you make butter. So I'm leaning towards the conclusion that long, violent milk shaking is probably going to do something fairly profound to the milk - although whether that is relevant as regards its nutritional content for baby, I still have no idea. Would you agree?
 

Offline evan_au

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Re: Can shaking break down the amino acids in breastmilk?
« Reply #3 on: 23/05/2014 23:33:54 »
Shaking by hand is unlikely to do much damage to breast milk.
A blender or a high-power ultrasonic cleaner would mix the milk more thoroughly, but would do more damage to cells & proteins in the milk.

For nutritional purposes, a denatured protein is just as good as a non-denatured protein.
However, there are functional cells & proteins in milk, and the correct shape of these proteins is critical for their function:
Quote
Breast milk also contains antibodies and lymphocytes from the mother that help the baby resist infections. The immune function of breast milk is individualized, as the mother, through her touching and taking care of the baby, comes into contact with pathogens that colonize the baby, and, as a consequence, her body makes the appropriate antibodies and immune cells.

Proteins will be undamaged by cooling. Immune cells would probably survive the refrigerator for a few hours, but would probably be killed by freezing.

Antibodies & white blood cells would be damaged by heating to elevated temperatures (above 40C) , and no longer carry out their antibacterial/anti-viral function.

The adult digestive system is very good at breaking down all the proteins in food - but I vaguely recall that the baby's digestive system is more porous? This would allow the baby to absorb antibodies and immune cells.
« Last Edit: 23/05/2014 23:50:28 by evan_au »
 

Offline Saartjie

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Re: Can shaking break down the amino acids in breastmilk?
« Reply #4 on: 24/05/2014 09:43:06 »
Ok - so a little gentle shaking is probably fine, but more than that will start to have an effect, and a lot of the advantages of breastmilk over formula are lost. Thanks, its really cool to have a bit of a better handle on the science of this!
 

Offline CliffordK

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Re: Can shaking break down the amino acids in breastmilk?
« Reply #5 on: 24/05/2014 19:35:56 »
You might look up milk homogenization, but that would be a much more aggressive practice than a little shaking at home.

For the immune activity, the most important milk would be that containing colostrum, from the first few days after birth.  There may be some antibodies in later milk, but at lower levels.  Maternal antibodies will remain active in the baby for a couple of months, so missing a "dose" would not be significant.
 

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Re: Can shaking break down the amino acids in breastmilk?
« Reply #5 on: 24/05/2014 19:35:56 »

 

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