Purpose: It was already reported that umami peptides (Glu-Asp, Glu-Glu, Glu-Ser, Asp-Glu-Ser, Glu-Gly-Ser) derived from soybean markedly attenuated the salicin-induced intracellular calcium influx in a time-dependent manner, respectively1). The purpose of this study was to evaluate the bitterness masking effect of umami peptide on bitter drugs by taste sensor and human gustatory sensation test, thereby demonstrate usefulness of umami peptide as bitter taste masking agent for medicines.
Methods: Diphenhydramine hydrochloride (DPH) and donepezil hydrochloride (DNP) were used as models of bitter drugs. Twenty kinds of amino acids and five peptide (Glu-Glu, Glu-Asp, Glu-Ser, Asp-Asp, Gly Gly) were used to evaluate those utility as bitter taste masking agents. DPH or DNP (0.5 mM) mixed with or without amino acid or umami peptide (0.0001, 0.01, 0.05, 0.1, 0.5, 1.0, 5.0 mM) were analyzed by taste sensor (Intelligent Sensor Technology Inc., Atsugi, Japan). Human gustatory sensation test, approved by the ethical committee of Mukogawa Women’s University on Oct. 20, 2017, (n=7) in advance and carried out.
Results: As a result of taste sensor measurement, taste sensor outputs of DPH or DNP (0.5 mM) were significantly reduced by the addition of Glu, Asp, Glu-Asp, Glu-Ser, Asp-Asp (≧0.01 mM) in dose dependent manner, respectively. Whereas the taste sensor outputs of DPH or DNP (0.5 mM) were not reduced by the addition of Gly-Gly. As a result of human sensation test, bitterness intensity of DPH (0.5 mM) was approximately tau 2 which corresponds to the bitterness intensity of quinine 0.1 mM. The bitterness intensity of DPH (0.5 mM) was significantly suppressed by addition of Glu-Glu (0.5 mM) and Asp-Asp (0.5 mM), respectively.
Conclusion: Our findings by the taste sensor measurement and human sensation test of bitter drug solutions with umami peptides, confirmed the usefulness of umami peptide as taste masking agent for bitter drugs.
1) Kim MJ., et al., Biochem. Biophys. Res. Commun., 456(2), 586-90 (2015).