l-Theanine elicits umami taste via the T1R1 + T1R3 umami taste receptor

Narukawa, Masataka; Toda, Yasuka; Nakagita, Tomoya; Hayashi, Yukako; Misaka, Takumi

doi:10.1007/s00726-014-1713-3

Cited by 55 publications

(33 citation statements)

References 20 publications

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“…Specifically, theanine originally accounted for more than 50% of the total amino acids content was found to decrease over time, and this variation was consistent with previous report (Chatterjee, Chatterjee, & Bandyopadhyay, ). Theanine contributes to the sweet taste (Ekborg‐Ott, Taylor, & Armstrong, ; Yu, & Yang, ) as well as the umami (Juneja, Chu, Okubo, Nagato, & Yokogoshi, ; Narukawa, Toda, Nakagita, Hayashi, & Misaka, ) taste of tea infusions. Thus, free amino acids can be divided into sweet amino acids (gly, ser, ala, pro, thr, met, and theanine), bitter amino acids (arg, his, ile, leu, phe, lys, tyr, and val), and umami amino acids (asp, glu, and theanine) according to the different taste characteristics of amino acids (Scharbert & Hofmann, ; Zhang et al, ), and the contents of these amino acids were investigated (Figure ).…”

Section: Resultsmentioning

confidence: 99%

Distinct variation in taste quality of Congou black tea during a single spring season

Huang

Zhao

et al. 2020

Food Science & Nutrition

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The quality of Congou black tea fluctuates greatly with the changing seasons.However, variations in the taste quality of Congou black tea manufactured during a single spring season are far from clear. Here, we analyzed the taste quality of HuangJinCha (HJC) Congou black tea using sensory evaluation and found the taste quality of black tea manufactured in the early spring was better than that manufactured in the late spring. Principal component analysis (PCA) and cluster analysis for the data from the electronic tongue confirmed the variation and revealed that April 4 may be the critical time point at which variations in taste quality become apparent.The contents of tea polyphenols (TP), total catechins (TC), total flavones, (-)-epigallocatechin gallate (EGCG), (-)-epicatechin gallate (ECG), and gallic acid (GA) showed increasing trends, whereas total amino acids (TAA) declined over time. Moreover, the variations in total amino acids (r = 0.846) and total flavones (r = -0.858) were highly significantly correlated with the average taste quality score (p < .01), suggesting these compounds were the primary factors responsible for the fluctuation in taste quality of Congou black tea processed during a single spring season. K E Y W O R D Sblack tea, electronic tongue, sensory evaluation, spring season, taste quality

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Section: Resultsmentioning

confidence: 99%

Distinct variation in taste quality of Congou black tea during a single spring season

Huang

Zhao

et al. 2020

Food Science & Nutrition

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“…Assamica is a kind of amino acid exists in tea leaves such as C. japonica and C. sasanqua (Deng et al, 2008). Ltheanine contributes to the aroma of tea in a high level and especially it is related with the umami taste of the tea (Narukawa et al, 2014). L-theanine composes almost 50% of the free amino acids in the tea.…”

Section: 1natural Sourcesmentioning

confidence: 99%

L-theanine, unique amino acid of tea, and its metabolism, health effects, and safety

Türközü

Şanlıer

2015

Critical Reviews in Food Science and Nutrition

149

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Tea has been a very popular beverage around the world for centuries. The reason that it is delicious, enabling hydration, showing warming and relaxing effect can be mentioned why it is consumed so much in addition to its prominent health effects. Although the catechins and caffeine are the primary bioactive components that are related with the health effects of the tea, the health effects of theanine amino acid, which is a nonproteinic amino acid special to tea, has become prominent in recent years. It has been known that the theanine amino acid in tea has positive effects especially on relaxing, cognitive performance, emotional status, sleep quality, cancer, cardiovascular diseases, obesity, and common cold. The results of acute and chronic toxicity tests conducted on the safety of theanine express that L-theanine is reliable in general even if it is consumed too much with diet. However, it has not revealed a clear evidence-based result yet regarding theanine metabolism, health effects, and its safety. Within this frame, chemical structure of theanine, its biosynthesis, dietary sources, metabolism, health effects, and safety are discussed in present study.

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“…These include the amino acid theanine, methylxanthines (caffeine and theobromine), quinic acid esters as well as the diverse range of catechins and other flavonoids. Theanine accounts for about 60-70% of the total amino acid content in tea leaves and it stimulates the T1R1 and T1R3 umami taste receptors, thus it has an important effect on tea taste and quality (Chen, Apostolides, & Chen, 2013;Narukawa, Toda, Nakagita, Hayashi, & Misaka, 2014). The bitter-tasting caffeine and theobromine are associated with a diverse range of health benefits, although more studies are needed to support the efficacy of these compounds (Judelson, et al, 2013;Mitchell, et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

Variation of theanine, phenolic, and methylxanthine compounds in 21 cultivars of Camellia sinensis harvested in different seasons

et al. 2017

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This is the first study to use chemometric methods to differentiate among 21 cultivars of Camellia sinensis from China and between leaves harvested at different times of the year using 30 compounds implicated in the taste and quality of tea. Unique patterns of catechin derivatives were observed among cultivars and across harvest seasons. C. sinensis var. pubilimba (You 510) differed from the cultivars of C. sinensis var. sinensis, with higher levels of theobromine, (+)-catechin, gallocatechin, gallocatechin gallate and theasinensin B, and lower levels of (-)-epicatechin, (-)-epigallocatechin (EGC) and (-)-epigallocatechin gallate (EGCG), respectively. Three cultivars of C. sinensis var. sinensis, Fuyun 7, Qiancha 7 and Zijuan contained significantly more caffeoylquinic acids than others cultivars. A Linear Discriminant Analysis model based on the abundance of 12 compounds was able to discriminate amongst all 21 tea cultivars. Harvest time impacted the abundance of EGC, theanine and afzelechin gallate.

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l-Theanine elicits umami taste via the T1R1 + T1R3 umami taste receptor

Cited by 55 publications

References 20 publications

Distinct variation in taste quality of Congou black tea during a single spring season

Distinct variation in taste quality of Congou black tea during a single spring season

L-theanine, unique amino acid of tea, and its metabolism, health effects, and safety

Variation of theanine, phenolic, and methylxanthine compounds in 21 cultivars of Camellia sinensis harvested in different seasons

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