Tea is the world＇s oldest and most popular caffeine-containing beverage with immense economic, medicinal, and cultural importance. Here, we present the first high-quality nucleotide sequence of the repeat-rich （80.9...Tea is the world＇s oldest and most popular caffeine-containing beverage with immense economic, medicinal, and cultural importance. Here, we present the first high-quality nucleotide sequence of the repeat-rich （80.9%）, 3.02-Gb genome of the cultivated tea tree Camellia sinensis. We show that an extraordinarily large genome size of tea tree is resulted from the slow, steady, and long-term amplification of a few LTR retrotransposon families. In addition to a recent whole-genome duplication event, lineage-specific expansions of genes associated with flavonoid metabolic biosynthesis were discovered, which enhance catechin production, terpene enzyme activation, and stress tolerance, important features for tea flavor and adaptation. We demonstrate an independent and rapid evolution of the tea caffeine synthesis pathway relative to cacao and coffee. A comparative study among 25 Camellia species revealed that higher expression levels of most flavonoid- and caffeinebut not theanine-related genes contribute to the increased production of catechins and caffeine and thus enhance tea-processing suitability and tea quality. These novel findings pave the way for further metabolomic and functional genomic refinement of characteristic biosynthesis pathways and will help develop a more diversified set of tea flavors that would eventually satisfy and attract more tea drinkers worldwide.展开更多
The goals of this study were to examine, using the temporal dominance of sensations (TDS) method, the effects of 1) the sucrose concentration on the temporal sequence of sweetness perception in four fruit-flavored (le...The goals of this study were to examine, using the temporal dominance of sensations (TDS) method, the effects of 1) the sucrose concentration on the temporal sequence of sweetness perception in four fruit-flavored (lemon, peach, strawberry, and vanilla) teas with 0.05, 0.15, and 0.25 M sucrose;and 2) participants’ sex on this temporal sequence. Twenty-four healthy young adults were assigned to female (n = 12) and male (n = 12) groups. Both groups evaluated five sensory attributes in 12 samples (four fruit-flavored teas, each with three sucrose concentrations). As in our preceding study [1], two sensations, sweetness and fruitiness, were dominant after ingesting the 12 teas in both groups, but the temporal sequence of sweetness perception differed between the two groups. On average, the male group reported the first appearance of sweetness earlier in the samples with 0.05 M sucrose compared with the female group, with the samples containing 0.15 and 0.25 M sucrose. The average durations of the sweetness sensation were different between the male and female groups as well as among the sucrose concentrations and the four flavors tested.展开更多
The goal of this preliminary study was to examine the effect of participants’ sexes on the temporal sequence of dominant sensations elicited by fruit-flavored teas. Twelve healthy young adults were assigned to male (...The goal of this preliminary study was to examine the effect of participants’ sexes on the temporal sequence of dominant sensations elicited by fruit-flavored teas. Twelve healthy young adults were assigned to male (n = 6) and female (n = 6) groups. Both groups were evaluated for four sensations using four fruit-flavored teas with 0.05 M sucrose using the temporal dominance of sensations (TDS) method. Only two sensations, sweetness and fruitiness, were consistently reported in the two groups. The male group first reported fruitiness and then sweetness as the dominant sensation following ingestion of the samples. Conversely, the female group reported these two dominant sensations in the reverse order. Significant dominant durations between the two sensations largely varied among the samples in both groups. These results suggest that there are sex-based differences in the temporal sequence of dominant sensations elicited by fruit-flavored teas as evaluated by the TDS method.展开更多
In order to change for the good flavor in green tea of middle or low grade,roast naked barley(miner ingredient) was added to it.To make tea having functional property,mixed roast naked barley-green tea with one medici...In order to change for the good flavor in green tea of middle or low grade,roast naked barley(miner ingredient) was added to it.To make tea having functional property,mixed roast naked barley-green tea with one medicinal herb(MH,miner ingredient).This study was performed to investigate the effect of drinking extracts of naked barley- MH- green tea(A group) and adlay- Angelica gigas Nakai- green tea(B group) on the body weights of rats,and volatile flavor components of best effective extract on weight reduction.Forty-eight male Sprague-Dawley rats divided into six groups were fed five different green tea extracts for 8 weeks.The result obtained in the experiment indicated that the change of body weights of rats was affected by A group,B group and others.A group showed highest reduction rate of body weights(36.40%).Reduction rate of body weights on the B group(10.10%) was much lower than A group(36.40%).Aroma compounds were extracted by the SDE method.The concentrated aroma extracts were analyzed and identified by GC and GC-MS.The main aroma components of the green tea blended with naked barley and MH were 12 pyrazines having roasty note,methyl butanals having sweet note,hexanal having briskness greenish note,and nerolidol and β-ionone having floral note.展开更多
基金This work was supported by the project of Yunnan Innovation Team Project, the Hundreds Oversea Talents Program of Yunnan Province, the Top Talents Program of Yunnan Province （Grant 20080A009）, the Key Project of the Natural Science Foundation of Yunnan Province （201401 PC00397）, National Science Foundation of China （U0936603）, Key Project of Natural Science Foundation of Yunnan Province （2008CC016）, Frontier Grant of Kunming Institute of Botany, CAS （672705232515）, Top Talents Program of Yunnan Province （20080A009）, and Hundreds Talents Program of Chinese Academy of Sciences （CAS） （to L.G.）.
文摘Tea is the world＇s oldest and most popular caffeine-containing beverage with immense economic, medicinal, and cultural importance. Here, we present the first high-quality nucleotide sequence of the repeat-rich （80.9%）, 3.02-Gb genome of the cultivated tea tree Camellia sinensis. We show that an extraordinarily large genome size of tea tree is resulted from the slow, steady, and long-term amplification of a few LTR retrotransposon families. In addition to a recent whole-genome duplication event, lineage-specific expansions of genes associated with flavonoid metabolic biosynthesis were discovered, which enhance catechin production, terpene enzyme activation, and stress tolerance, important features for tea flavor and adaptation. We demonstrate an independent and rapid evolution of the tea caffeine synthesis pathway relative to cacao and coffee. A comparative study among 25 Camellia species revealed that higher expression levels of most flavonoid- and caffeinebut not theanine-related genes contribute to the increased production of catechins and caffeine and thus enhance tea-processing suitability and tea quality. These novel findings pave the way for further metabolomic and functional genomic refinement of characteristic biosynthesis pathways and will help develop a more diversified set of tea flavors that would eventually satisfy and attract more tea drinkers worldwide.
文摘The goals of this study were to examine, using the temporal dominance of sensations (TDS) method, the effects of 1) the sucrose concentration on the temporal sequence of sweetness perception in four fruit-flavored (lemon, peach, strawberry, and vanilla) teas with 0.05, 0.15, and 0.25 M sucrose;and 2) participants’ sex on this temporal sequence. Twenty-four healthy young adults were assigned to female (n = 12) and male (n = 12) groups. Both groups evaluated five sensory attributes in 12 samples (four fruit-flavored teas, each with three sucrose concentrations). As in our preceding study [1], two sensations, sweetness and fruitiness, were dominant after ingesting the 12 teas in both groups, but the temporal sequence of sweetness perception differed between the two groups. On average, the male group reported the first appearance of sweetness earlier in the samples with 0.05 M sucrose compared with the female group, with the samples containing 0.15 and 0.25 M sucrose. The average durations of the sweetness sensation were different between the male and female groups as well as among the sucrose concentrations and the four flavors tested.
文摘The goal of this preliminary study was to examine the effect of participants’ sexes on the temporal sequence of dominant sensations elicited by fruit-flavored teas. Twelve healthy young adults were assigned to male (n = 6) and female (n = 6) groups. Both groups were evaluated for four sensations using four fruit-flavored teas with 0.05 M sucrose using the temporal dominance of sensations (TDS) method. Only two sensations, sweetness and fruitiness, were consistently reported in the two groups. The male group first reported fruitiness and then sweetness as the dominant sensation following ingestion of the samples. Conversely, the female group reported these two dominant sensations in the reverse order. Significant dominant durations between the two sensations largely varied among the samples in both groups. These results suggest that there are sex-based differences in the temporal sequence of dominant sensations elicited by fruit-flavored teas as evaluated by the TDS method.
文摘In order to change for the good flavor in green tea of middle or low grade,roast naked barley(miner ingredient) was added to it.To make tea having functional property,mixed roast naked barley-green tea with one medicinal herb(MH,miner ingredient).This study was performed to investigate the effect of drinking extracts of naked barley- MH- green tea(A group) and adlay- Angelica gigas Nakai- green tea(B group) on the body weights of rats,and volatile flavor components of best effective extract on weight reduction.Forty-eight male Sprague-Dawley rats divided into six groups were fed five different green tea extracts for 8 weeks.The result obtained in the experiment indicated that the change of body weights of rats was affected by A group,B group and others.A group showed highest reduction rate of body weights(36.40%).Reduction rate of body weights on the B group(10.10%) was much lower than A group(36.40%).Aroma compounds were extracted by the SDE method.The concentrated aroma extracts were analyzed and identified by GC and GC-MS.The main aroma components of the green tea blended with naked barley and MH were 12 pyrazines having roasty note,methyl butanals having sweet note,hexanal having briskness greenish note,and nerolidol and β-ionone having floral note.
