Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 3 de 3
Filter
Add more filters










Database
Language
Publication year range
1.
Biosci Biotechnol Biochem ; 82(9): 1539-1549, 2018 Sep.
Article in English | MEDLINE | ID: mdl-29912652

ABSTRACT

Some components of bitterness make key flavor contributions to promote the palatability of foods, whereas other components are recognized as aversive signals to avoid consuming harmful substances. These contradictory behaviors suggest that humans tolerate tastes of bitterants based on certain criteria. Here, we investigated human taste tolerance and sensory cues leading to diverse taste tolerance of bitter compounds. Tolerance of eight bitter compounds, which are typically contained in foods, was evaluated by measuring detection and rejection thresholds. The results revealed that the level of tolerance of each compound was variable, and some compounds showed an acceptable concentration regarding the suprathreshold intensity. Tolerance did not depend on the nutritive value or attenuation and accumulation characteristics of bitterness and bitter taste receptors. These results suggest that the criteria controlling tolerance of bitter compounds may be derived from a complex relationship between the taste quality and cognitive process.


Subject(s)
Adaptation, Physiological , Taste Buds/physiology , Taste Threshold , Taste , Adult , Female , Humans , Male , Young Adult
2.
PLoS One ; 13(12): e0210032, 2018.
Article in English | MEDLINE | ID: mdl-30596779

ABSTRACT

Tolerance to bitter foods and its potentiation by repetitive exposure are commonly experienced and potentially underlie the consumption of bitter foods, but it remains unknown whether permissive and adaptive responses are general phenomena for bitter-tasting substances or specific to certain substances, and they have not been rigorously studied in mice. Here, we investigated the effects of prolonged exposure to a bitter compound on both recognition and rejection behaviors to the same compound in mice. Paired measurements of rejection (RjT) and apparent recognition (aRcT) thresholds were conducted using brief-access two-bottle choice tests before and after taste aversion conditioning, respectively. First, RjT was much higher than aRcT for the bitter amino acids L-tryptophan and L-isoleucine, which mice taste daily in their food, indicating strong acceptance of those familiar stimuli within the concentration range between RjT and aRcT. Next, we tested five other structurally dissimilar bitter compounds, to which mice were naive at the beginning of experiments: denatonium benzoate, quinine-HCl, caffeine, salicin, and epigallocatechin gallate. RjT was moderately higher than aRcT for all the compounds tested, indicating the presence of innate acceptance to these various, unfamiliar bitter stimuli in mice. Lastly, a 3-week forced exposure increased RjT for all the bitter compounds except salicin, demonstrating that mice acquire tolerance to a broad array of bitter compounds after long-term exposure to them. Although the underlying mechanisms remain to be determined, our studies provide behavioral evidence of innate and acquired tolerance to various bitter stimuli in mice, suggesting its generality among bitterants.


Subject(s)
Adaptation, Physiological/drug effects , Behavior, Animal/drug effects , Isoleucine/pharmacology , Taste Perception/drug effects , Tryptophan/pharmacology , Animals , Female , Mice
3.
ACS Macro Lett ; 4(2): 247-250, 2015 Feb 17.
Article in English | MEDLINE | ID: mdl-35596416

ABSTRACT

The controlled formation and the regular arrangement of polymer chains have been performed by novel solid-state polycondensation including the ionic-to-covalent bond transformation in the ionic molecular crystals. The combination of the tetra-anion and -cation of tetraphenylporphyrin derivatives, tetrakis(benzylpyridinium carboxylate), was found to form layered crystal structures and underwent thermal solid-state polycondensation, thus, releasing the pyridine and forming the benzyl ester linkages. Powder X-ray diffraction, when compared to the monomer crystal structure data, suggested that the ladder polymer was produced with a layered structure.

SELECTION OF CITATIONS
SEARCH DETAIL
...