Nakamura Tomoko, Tanigake Atsu, Miyanaga Yohko, Ogawa Tazuko, Akiyoshi Takeshi, Matsuyama Kenji, Uchida Takahiro
School of Pharmaceutical Sciences, Mukogawa Women's University, Nishinomiya, Japan.
Chem Pharm Bull (Tokyo). 2002 Dec;50(12):1589-93. doi: 10.1248/cpb.50.1589.
The purpose of this study was to quantify the degree of suppression of the perceived bitterness of quinine by various substances and to examine the mechanism of bitterness suppression. The following compounds were tested for their ability to suppress bitterness: sucrose, a natural sweetener; aspartame, a noncaloric sweetener; sodium chloride (NaCl) as the electrolyte; phosphatidic acid, a commercial bitterness suppression agent; and tannic acid, a component of green tea. These substances were examined in a gustatory sensation test in human volunteers, a binding study, and using an artificial taste sensor. Sucrose, aspartame, and NaCl were effective in suppressing bitterness, although at comparatively high concentrations. An almost 80% inhibition of bitterness (calculated as concentration %) of a 0.1 mM quinine hydrochloride solution required 800 mM of sucrose, 8 mM of aspartame, and 300 mM NaCl. Similar levels of bitterness inhibition by phosphatidic acid and tannic acid (81.7, 61.0%, respectively) were obtained at much lower concentrations (1.0 (w/v)% for phosphatidic acid and 0.05 (w/v)% for tannic acid). The mechanism of the bitterness-depressing effect of phosphatidic acid and tannic acid was investigated in terms of adsorption and masking at the receptor site. With phosphatidic acid, 36.1% of the bitterness-depressing effect was found to be due to adsorption, while 45.6% was due to suppression at the receptor site. In the case of 0.05 (w/v)% tannic acid, the total bitterness-masking effect was 61.0%. The contribution of the adsorption effect was about 27.5% while the residual masking effect at the receptor site was almost 33%. Further addition of tannic acid (0.15 (w/v)%), however, increased the bitterness score of quinine, which probably represents an effect of the astringency of tannic acid itself. Finally, an artificial taste sensor was used to evaluate or predict the bitterness-depressing effect. The sensor output profile was shown to reflect the depressant effect at the receptor site rather well. Therefore, the taste sensor is potentially useful for predicting the effectiveness of bitterness-depressant substances.
本研究的目的是量化各种物质对奎宁苦味的抑制程度，并探究苦味抑制的机制。测试了以下化合物抑制苦味的能力：天然甜味剂蔗糖、无热量甜味剂阿斯巴甜、作为电解质的氯化钠（NaCl）、商业苦味抑制剂磷脂酸以及绿茶成分单宁酸。在人体志愿者的味觉测试、结合研究以及使用人工味觉传感器的实验中对这些物质进行了检测。蔗糖、阿斯巴甜和NaCl在相对较高的浓度下能有效抑制苦味。对于0.1 mM的盐酸奎宁溶液，要实现近80%的苦味抑制（以浓度计），需要800 mM蔗糖、8 mM阿斯巴甜和300 mM NaCl。在低得多的浓度下（磷脂酸为1.0（w/v）%，单宁酸为0.05（w/v）%），磷脂酸和单宁酸也能实现类似程度的苦味抑制（分别为81.7%和61.0%）。从受体部位的吸附和掩盖作用方面对磷脂酸和单宁酸的苦味抑制作用机制进行了研究。对于磷脂酸，发现其苦味抑制作用的36.1%归因于吸附，而45.6%归因于受体部位的抑制作用。对于0.05（w/v）%的单宁酸，总的苦味掩盖作用为61.0%。吸附作用的贡献约为27.5%，而受体部位的剩余掩盖作用约为33%。然而，进一步添加单宁酸（0.15（w/v）%）会使奎宁的苦味评分增加，这可能是单宁酸本身的涩味作用。最后，使用人工味觉传感器来评估或预测苦味抑制效果。结果表明传感器输出曲线能较好地反映受体部位的抑制效果。因此，味觉传感器在预测苦味抑制物质的有效性方面可能具有潜在用途。
