Can someone please explain why baby rice cereal goes sloppier rather than thicker over time?

June 28, 2012 4:38 PM

I am currently feeding my baby rice cereal (just powdered rice) which I mix with a little hot water and breast milk into a sort of thick goop however I have noticed that if I leave it for around five or so minutes it begins to turn into a much runnier almost liquid consistency. I would have thought it would have got thicker over time. Could someone please explain why this happens?
posted by soymilk to Food & Drink (5 answers total)

I've heard, and and general Internet lore at least supports it, that breast milk has enzymes that break down rice cereal. Formula and the such will thicken over time, as you'd expect. Some people suggest not mixing breast milk as it's a "waste" of good milk since it's likely the kid won't eat all (or even most) of the mixture.
posted by skynxnex at 4:49 PM on June 28, 2012

Response by poster: Wow thanks, that's really interesting! Ok, I might do an experiment with just water to see what happens.
I know what you mean about the wastage, it really is liquid gold :)
posted by soymilk at 5:05 PM on June 28, 2012

This could also be a miscibility issue due to the way fats, proteins and starches mix (or don't).

As long as you're experimenting, and you're worried about wastage, try it with regular grocery store milk and see what happens. If you don't get the same effect, you could try exposing a small amount of breast milk to about 150° F for a minute, chill it back down (you'll want to use metal for this) and see if it still has the same effect or if pasteurization kills it.
posted by Kid Charlemagne at 5:36 PM on June 28, 2012

Best answer: Breast milk has amylase, the same enzyme in your saliva that breaks the bonds in starch to free sugars (a fun experiment to do with kids is to have them chew a piece of whole wheat bread for a long time without swallowing, appreciating how the mastication becomes extremely sweet). The amylase in breast milk in there to break down the large amount of lactose in breast milk (the primary carbohydrate in breast milk). Of course, it will also break the bonds in any other starch, like rice starch making the cereal sweeter and thinner in consistency. Some amylase will get destroyed by heating the breast milk beforehand, but this may make the resulting cereal more difficult to digest for the infant, depending on how mature the exocrine features of the baby's pancreas has become (our pancreas makes digestive enzymes). Usually, simply feeding the cereal before its too thin to spoon, or using water to mix is a better method.

Breast milk also has lipase, an enzyme that breaks the rather large fat globule in breast milk into much smaller components. This is why some women will notice that their own stored breast milk smells or tastes "soapy," even when stored within recommended guidelines. The lipase has broken down the fat so effectively that our own tastebuds compare this refinement to the broken down fats in soap. This rarely bothers the baby (as far as taste or GI issues).

It's kind of cool that breast milk, the the absence of fully developed or matured enzymatic action in the infant GI tract (or exocrine glands), "comes with" these necessary enzymes--it has the food AND the tools to cook it all-in-one.

Related coolness--the composition of your milk will demonstrate less enzyme as your baby grows older. The whole program, the maturation of your baby and the maturation of your milk, runs together.
posted by rumposinc at 5:54 PM on June 28, 2012 [21 favorites]

Response by poster: Well I did two experiments, one adding only water and one with cow's milk and sure enough they both stayed thick and eventually went thicker!
Thanks heaps for your answers, add that to the many wonders of breastmilk! :)
posted by soymilk at 5:30 AM on June 29, 2012 [1 favorite]