Abstract:

Carboxymethyl konjac glucomannan (CMK) made from konjac glucomannan (KGM) from Amorphophallus
bulbifer shows a good film-forming property. CMK-KGM blend membrane has a better strength of extension and
elongation at break and a similar clarity when compared to the film made from simplex KGM. However, there
has been no published report regarding the intestinal health effect of CMK. For better understanding CMK, we
investigated its physico-chemical properties and fermentation characteristics in vitro. The results showed similar
apparent properties between KGM and CMK. Both of them were odorless, soluble in water and insoluble in ethanol, ether
and other organic solvents, but CMK had significantly higher ash content and significantly lower viscosity. Moreover, results
of in vitro fermentation showed that CMK showed very slight effect on gas production or the content of short-chain fatty
acid (SCFA) but resulted in a significant reduction in NH3-N content. CMK neither promoted nor inhibited the growth of
Bifidobacterium or E. coli, but had a promoting effect on the growth of Lactobacillus. To conclude, while the potential role
of KGM in promoting intestinal health, CMK has no adverse effect on intestinal health.

Key words: carboxymethyl konjac glucomannan (CMK), physico-chemical properties, in vitro fermentation characteristics, short-chain fatty acid (SCFA), microbe