| Project/Area Number |
10470358
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| Research Category |
Grant-in-Aid for Scientific Research (B).
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Otorhinolaryngology
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| Research Institution | Kagoshima University |
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Principal Investigator |
HARADA Shuitsu Kagoshima University, Dental School, Associate Professor, 歯学部, 助教授 (60128452)
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| Co-Investigator(Kenkyū-buntansha) |
KAMEYAMA Masaki Kagoshima University, Faculty of Medicine, Professor, 医学部, 教授 (60150059)
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| Project Period (FY) |
1998 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥6,800,000 (Direct Cost: ¥6,800,000)
Fiscal Year 2000: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 1999: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1998: ¥4,700,000 (Direct Cost: ¥4,700,000)
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| Keywords | Taste / Umami / Synergistic effect / Citric acids / Amino acid / Rat / Human / 二瓶選択法 / 官能検査 / グルタミン酸ソーダ / 哺乳類 / 味覚修飾作用 / 甘味物質 / 可溶性澱粉 / 大錐体神経 / 鼓索神経 / グルマリン / 甘味 |
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| Research Abstract |
1) Result from the experiment of the rat greater superficial petrosal (GSP) nerve innervating the soft palate revealed that the integrated responses from the GSP to six sugars and saccharin were significantly depressed to 40% after gurmarin treatment. Responses to D-amino acids were more significantly inhibited than that to L-amino acids by the gurmarin treatment. These results suggest that the difference of receptor molecule and/or transduction mechanisms for amino acids is similar to those for sweet substances in the rat. Lowering the pH of basic and neutral amino acid solutions by adding inorganic acids resulted in the enhancement of neural responses in the rat chorda tympani, concerning to the charge of a-amino group in the amino acid molecule. Therefore, taste stimulatory effectiveness of citric acid may not only be concerned to a stimulant as di-carbonic acids but also to the enhancement of stimulatory effectiveness of amino acids by lowering pH as acid.
2) In humans, a greater sweetness intensity occturred to sucrose dissolved in a soluble starch than for sucrose dissolved in distilled water. However, citric acid NA (CitNa) did not alter the enhancement effect on sweetness by soluble starch. A greater umami intensity occurred in response to CitNa.
3) A two-bottle preference test in the preference ratio for MSG + CitNa tended to be larger than that for MSG.Also, the rat tended to prefer MSG + IMP + CitNa to MSG + IMP.These results suggest that CitNa may have enhancing effects on umami taste in mammals.
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