Konjac
The short version
Glucomannan from the konjac corm — a powerful thickener and the gelling agent in shirataki noodles. Choking hazard in jelly minicups.
It's permitted and generally considered safe, but there are a few reasons to be mindful — like sensitivities in some people, debated studies, or intake limits. The Safety section below explains the specifics.
Where it comes from
Extracted from the corm (underground stem) of Amorphophallus konjac, a plant native to East Asia and cultivated in Japan, China, and Southeast Asia for over a millennium. The dried corm is milled and the glucomannan fraction purified by repeated grinding and air separation.
How it's used
The base of shirataki/konnyaku noodles, jelly desserts, vegan gummies, and an increasingly common thickener in low-carb and weight-loss foods. Forms a strong thermo-irreversible gel with alkali (calcium hydroxide) and a thermo-reversible gel with xanthan or carrageenan.
Safety profile
ADI not specified — considered safe as a soluble fiber when consumed in solution. The critical safety concern is texture: konjac jelly minicups (small pop-out cups) caused fatal choking incidents in children and were banned in the EU, US, Canada, and Australia. Consumed in liquid or paste form (noodles, drinks), no choking concern; soluble fiber may contribute to gut motility changes at high intake.
Physical & chemical properties
Off-white powder, swells dramatically in water (10–100× by volume). Forms a viscous solution; gels on heating with alkali. Combined with xanthan, produces elastic, thermo-reversible gels at low concentrations.
Regulation worldwide
Permitted globally for most food categories; banned specifically in jelly minicup format in the EU, US, Canada, Australia, and Brazil.
Educational information only. Not medical or dietary advice.