Quantitative expression of mixed taste of amino acids using multichannel taste sensor

Amino acids with different functional group show different taste such as bitterness, sweetness and umami. Some of them elicit complicated mixed taste; e. g., L-methionine tastes bitter and sweet simultaneously. A multichannel taste sensor using lipid membranes was applied to amino acids. It was shown that bitter amino acids such as L-tryptophan have response electric patterns similar to a typical bitter substance, quinine, that belongs to alkaloids. The response pattern for L-methionine was found to be similar to that for a mixed solution composed of a sweet amino acid (L-alanine) and bitter amino acid (L-tryptophan). These results agreed quantitatively with human sensory evaluations.