This might be an odd question. But I am making gummybears from fruit i mixed smooth in a food processor and agar agar. I read that agar is a potential chocking hazard when taken with insufficient amount of water. Since I used about 3 teaspoons for my mixture to set it firm, will it expand once it comes in contact with the fluid when eaten? Or is the structure changed once it got heated and then cooled again into jelly form?

  • Agar is a gelling agent, made from seaweed. I can't imagine how it would be a choking hazard. Gummies themselves, of course, could be a choking hazard.
    – moscafj
    Apr 9, 2018 at 17:50
  • @moscafj Certain gelling agents can increase the risk of choking because of their nature (en.wikipedia.org/wiki/Konjac#Choking_risk). I don't think that applies to agar, though.
    – JAB
    Apr 9, 2018 at 17:52
  • 1
    From that website I get the impression that it is about digesting agar directly (or at least in large quantities in order to lose weight): Take agar on an empty stomach with at least 8 ounces of water. That would not apply in your case.
    – user34961
    Apr 10, 2018 at 12:40
  • I have edited your text and changed choking to obstruction. I assume you did not mean suffocation. If you did mean choking your question needs a rewrite because that is not in the stomach and that link does not apply.
    – user34961
    Apr 10, 2018 at 12:42
  • I am wondering about obstruction and if it is a choking hazard actually. I will edit it once I am able to get to the webmd page: webmd.com/vitamins-supplements/… Apr 10, 2018 at 13:15

3 Answers 3


Assuming that you are worried about the expansion rate in the stomach from having an insufficient ratio of water to agar during digestion, a quick search came up with the following results from wikipedia (https://en.wikipedia.org/wiki/Agar):

Agar-agar is approximately 80% fiber, so it can serve as an intestinal regulator. Its bulking quality has been behind fad diets in Asia, for example the kanten (the Japanese word for agar-agar[3]) diet. Once ingested, kanten triples in size and absorbs water. This results in the consumers feeling fuller. This diet has recently received some press coverage in the United States as well. The diet has shown promise in obesity studies.

The same Agar used in culinary dishes is the same one used in laboratories for testing. Resistance to high temperature (melting point is 85 °C) makes Agar ideal for studies that need an environment to mimic human body temperature. This means that Agar will not melt in the body once digested.

Melting Agar is also not the same as denaturing Agar. The act of melting it to form and then cooling to set does not change the structure and properties of Agar. Just like how ice melts into water and you can freeze again while also being able to reverse the process at any time, you can do the same with Agar just at a different temperature. Since the Agar has the same properties as before melting, this does not keep it from expanding when exposed to water.

To add to this: Just because your body does not get hot enough to melt agar, that does not mean the bacteria in your intestine won't break it down into smaller molecules and denature the Agar to aid in digestion. Source: https://www.ayurtimes.com/agar-agar-kanten/

  • "Since the Agar has the same properties as before melting, this does not keep it from expanding when exposed to water." does this conflict with the answer @Bugmo gave "Like other gelling agents, agar becomes more liquified and hence softer ..." or do is it expanding but liquefying more? I guess my worry is that if the gummy bears have enough agar in them that they will only expand to a point where they can become a danger and not enough to be liquid. Apr 10, 2018 at 11:41
  • @OliverSchöning The more liquid you add, the less absorption will take place. That will have to do with the saturation properties of Agar though and that has more to do with chemistry. For a rough guess you would need "20 times the weight of the agar in water" to keep further absorption to happen, but that makes unsatisfying gummies. The only saturation statistics I could find on Agar are at this link (very chemistry oriented): agargel.com.br/agar-tec-en.html Apr 10, 2018 at 15:26
  • @OliverSchöning I wouldn't worry about Agar expanding to be a danger unless you are eating super concentrated Agar gummies (to the point they would be borderline inedible) and you are dehydrated. As agar expands and absorbs water it will break down into smaller chunks by the churning of your digestive system. As long as you drink some water while eating your gummies you should be fine. Apr 10, 2018 at 15:30

The short answer is: Yes, it can. But it's not really about dilution.

Agar agar, along with foods such as chia seeds and flax seeds, are mucilaginous. This property can indeed pose a hazard if the ingredient is consumed while it still possesses a substantial capacity to absorb water. In this case, the product absorbs moisture from the alimentary canal, which can lead to an obstruction of the gut. There is at least one well-documented case of this occurring with chia seeds.

This risk can be completely mitigated by near-total hydration of the ingredient, i.e., by assuring that its capacity to absorb water has been nearly exhausted. To do so, find the absorptive capacity of the ingredient. My research found that agar agar's capacity is to absorb about 20 times its weight in water. Thus if your finished product contains 1Kg (1 liter) of water and 50 grams of agar agar, you have nothing to worry about. (You should do your own research and not rely on mine.)

I would guess that your finished product is actually substantially dryer than that, and as such, consuming substantial quantities of the product along with dehydration could lead to an obstruction. I would suggest eating this "food" with water.


Like other gelling agents, agar becomes more liquified and hence softer in the presence of the warmth of one's body and the liquid present in the digestive system. Therefor the cooked agar is not in itself a choking hazard, though, as noted above, the gummies could be. It is only agar that has not been combined with liquid, heated, and gelled that it is a choking hazard. So your cooked agar is not a danger. (Though I did notice a distinct flavor from the agar when I made a similar recipe several years ago.)

  • Do you mean the gummies could be a choking hazard in the same sense how all foods can be a choking hazard? Not rapid expansion. Apr 10, 2018 at 8:49
  • 1
    exactly, yes. Not rapid expansion.
    – Bugmo
    Apr 11, 2018 at 1:07

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