The masking of bitterness is considered important because many pharmaceutical compounds have a bitter taste. The bitterness-masking effect of powdered roasted soybeans (PRS) was investigated using a bitter taste sensor. PRS was revealed to significantly suppress the bitterness of quinine hydrochloride and denatonium benzoate. Furthermore, the bitterness-masking mechanism of PRS extracts was evaluated using dynamic light scattering. These results showed that the extracted suspension consisted of particles that were several hundreds of nanometers in size. Analysis of the PRS extracts by nuclear magnetic resonance spectroscopy indicated that denatonium benzoate was entrapped in the PRS extracts. Thus, PRS may be useful as a bitterness-masking agent in orally administered pharmaceuticals.
