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Insights into the organic acid and flavonoid metabolisms in moderately withered blueberries based on metabolomics and transcriptomics
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作者 Qin Yang Haijun Bi +6 位作者 Qi Zhang Shuqin Huang Chen Bian Lulu Zhao Hongbin Chen Xueling Gao Yu Wang 《Journal of Future Foods》 2026年第6期1155-1165,共11页
This study employed integrated metabolomic and transcriptomic analyses to investigate the impacts of moderate withering(approximately 30%weight loss)on organic acid and flavonoid accumulation in blueberries and the re... This study employed integrated metabolomic and transcriptomic analyses to investigate the impacts of moderate withering(approximately 30%weight loss)on organic acid and flavonoid accumulation in blueberries and the resultant blueberry wines.Moderate withering led to decreases in aliphatic organic acids but increases in phenolic acids and flavonoids in blueberries.The decrease in malate could be linked to the downregulated VcMDH and VcDTC,and the decrease in citrate and 2-oxoglutarate could be a consequence of y-aminobutyric acid shunt activation.The increases of phenolic acids were associated with upregulated VcCAD and VcPOD in withered blueberries.Additionally,moderate withering upregulated the expression of VcLAR and VcUFGT,promoting flavonoid accumulation.In blueberry wines,moderate withering decreased total aliphatic organic acid content but increased anthocyanin content,consistent with the findings in blueberries.Overall,this study provided references for applying moderate withering in blueberry winemaking,contributing to modulating acidity and enriching phenolic substances. 展开更多
关键词 BLUEBERRY Moderate withering Wine Organic acids Flavonoids
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Transcriptome and phytochemical analyses reveal the roles of characteristic metabolites in the taste formation of white tea during the withering process 被引量:15
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作者 ZHOU Cheng-zhe ZHU Chen +7 位作者 LI Xiao-zhen CHEN Lan XIE Si-yi CHEN Guang-wu ZHANG Huan LAI Zhong-xiong LIN Yu-ling GUO Yu-qiong 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2022年第3期862-877,共16页
In the postharvest processing of tea leaves,withering is the first indispensable manufacturing process which produces the mellow,umami and sweet taste of white tea.In this study,we aimed to determine the dynamic chang... In the postharvest processing of tea leaves,withering is the first indispensable manufacturing process which produces the mellow,umami and sweet taste of white tea.In this study,we aimed to determine the dynamic changes of the main metabolites and clarify the key differentially expressed genes(DEGs) involved in forming the characteristic taste of white tea during withering.Phytochemical analyses revealed that the contents of total catechins and starch decreased continuously,whereas the contents of theaflavin,γ-aminobutyric acid(GABA),maltose,and soluble sugars increased significantly during withering(from 0–48 h).Meanwhile,the elevation of α-amylase(AMY),β-amylase(BAM),total amylase,and glutamate decarboxylase(GAD) activities may be correlated with the accumulation of GABA and maltose.By transcriptome sequencing,we detected 9 707,15 921,17 353,and 17 538 DEGs at 12,24,36,and 48 h of the withering process,respectively,compared with 0 h sample(fresh leaves).The transcript levels of most of the DEGs involved in catechin biosynthesis were significantly inhibited,whereas those involved in catechin oxidation were significantly up-regulated,which could be correlated to a decrease in catechin content and an increase in theaflavin content.The DEGs involved in GABA biosynthesis were considerably up-regulated,and the down-regulation of SPMS could reduce the competition for converting spermidine to GABA.The up-regulation of the AMY and BAM genes could trigger starch degradation,resulting in the increase of soluble sugar content.These results provide new insights into the importance of the withering process to the characteristic taste of white tea. 展开更多
关键词 white tea witherING transcriptome analysis phytochemical analysis
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Effect of Sunlight Exposure and Different Withering Durations on Theanine Levels in Tea (<i>Camellia sinensis</i>) 被引量:1
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作者 Janet Chebet Too Thomas Kinyanjui +1 位作者 John Kanyiri Wanyoko Francis Nyamu Wachira 《Food and Nutrition Sciences》 2015年第11期1014-1021,共8页
Theanine is a non-protein amino acid representing as much as 50% of the total amino acids in black tea and 1% - 2% of dry weight in green tea. It has been shown to be able to reduce high blood pressure, promote relaxa... Theanine is a non-protein amino acid representing as much as 50% of the total amino acids in black tea and 1% - 2% of dry weight in green tea. It has been shown to be able to reduce high blood pressure, promote relaxation, and inhibit caffeine’s side effects among others. This current study explored the effects of sunlight and withering durations on theanine levels in tea shoots. Theanine content from three leaves and a bud, two leaves and a bud and internodes were detected and quantified by using High Performance Liquid chromatography (HPLC). Sunlight exposure experiment was started at dawn (0600 HRS, GMT + 3.00) when the light intensity was low and tea was collected at three-hour interval throughout the day to (1800 Hrs, GMT + 3.00) when the light intensity had dropped. At the start of the experiment, the theanine levels were significantly high but as the intensity of sunlight increased during the day there was a significant drop in theanine levels, and as the sun set the theanine levels increased significantly again in all samples. The results also showed that theanine levels were significantly increased after 15 hours of withering. Three leaves and a bud withered for 3 hours had mean theanine levels of 1.41% and those withered for 15 hours had mean theanine levels of 3.11%. Internodes exhibited higher mean theanine levels than those of leaves. In the light of these results, it’s evident that withering for a longer period of time and harvesting of tea when the light intensity is low ensure high amount of theanine in tea. 展开更多
关键词 Green TEA THEANINE witherING Time Sunlight Exposure Health Benefits
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Wither CIS?
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作者 刘桂玲 《Contemporary International Relations》 1998年第7期28-36,共9页
At the turn of the century, when big powers are readjusting their relations, ana-lysts are interested in what role the Commonwealth of Independent States(CIS) will play in an unfolding multipolar world in the forthcom... At the turn of the century, when big powers are readjusting their relations, ana-lysts are interested in what role the Commonwealth of Independent States(CIS) will play in an unfolding multipolar world in the forthcoming 21st century.For the moment, however, their attention is focused on the future of the CISitself, an organization committed to integration, yet still plagued with a 展开更多
关键词 wither CIS
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IMPACTED BY RIGHT-WING POPULISM, WITHER EUROPEAN INTEGRATION?
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作者 ZHENG CHUNRONG 《Contemporary World》 2017年第3期34-37,共4页
2017 is an election year for Europe,also a year on which hinges the destiny of Europe.In view of the general rise of right-wing populist parties in the EU,there have been concerns if another'black swan'would f... 2017 is an election year for Europe,also a year on which hinges the destiny of Europe.In view of the general rise of right-wing populist parties in the EU,there have been concerns if another'black swan'would fly out of the general elections of the Netherland,France and Germany.To date,the Dutch and French 展开更多
关键词 EU EU wither EUROPEAN INTEGRATION IMPACTED BY RIGHT-WING POPULISM
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香根草枯萎对根-土复合体抗剪强度的影响
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作者 张巍 麦宝妍 +3 位作者 陆建君 王克俭 徐东 徐文秀 《水土保持研究》 北大核心 2026年第1期383-391,共9页
[目的]研究根系枯萎对根-土复合体抗剪性能的影响,为植被斜坡滑坡灾害防治提供理论依据。[方法]以香根草和花岗岩风化土为研究对象,采用应变控制式直剪仪进行试验,分析了活根-土复合体和枯萎根-土复合体的黏聚力及内摩擦角与根系直径、... [目的]研究根系枯萎对根-土复合体抗剪性能的影响,为植被斜坡滑坡灾害防治提供理论依据。[方法]以香根草和花岗岩风化土为研究对象,采用应变控制式直剪仪进行试验,分析了活根-土复合体和枯萎根-土复合体的黏聚力及内摩擦角与根系直径、含水率等因素的关系。[结果](1)第0天与第56天相比,枯萎根根系直径缩小了10.4%~15.8%,枯萎90 d后的根系在外观和结构上与活根存在显著差异。(2)抗剪强度特征总体呈现素土试样<根-土复合体试样,在含水率为15%时,活根-土复合体试样与枯萎根-土复合体试样的抗剪强度差异较小,仅为5.51 kPa,但随着含水率的增加,枯萎根-土复合体试样的抗剪强度显著低于活根-土复合体试样。(3)活根-土复合体在四级含水率下仍有较高的黏聚力,而枯萎根-土复合体试样的黏聚力随着含水率上升而大幅下降。在含水率较低时,活根-土复合体与枯萎根-土复合体的根系黏聚力差距较小,但随着含水率增加,枯萎根-土复合体的根系黏聚力大幅下降,两者差距加大。[结论]在土壤含水率较低时,根系枯萎对固土效应的影响较小,但随着含水率的增加,枯萎根的固土效应逐渐减弱,当根-土复合体接近饱和时,枯萎根的固土效应几乎消失,需特别关注植物枯萎导致的根系固土效应降低及其可能引发的降雨诱发滑坡灾害。 展开更多
关键词 根系固土 抗剪强度 枯萎根 活根 香根草
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RNA Methylome Reveals the m^(6)A-mediated Regulation of Flavor Metabolites in Tea Leaves under Solar-withering 被引量:3
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作者 Chen Zhu Shuting Zhang +8 位作者 Chengzhe Zhou Caiyun Tian Biying Shi Kai Xu Linjie Huang Yun Sun Yuling Lin Zhongxiong Lai Yuqiong Guo 《Genomics, Proteomics & Bioinformatics》 SCIE CAS CSCD 2023年第4期769-787,共19页
The epitranscriptomic mark N6-methyladenosine(m^(6)A),which is the predominant internal modification in RNA,is important for plant responses to diverse stresses.Multiple environmental stresses caused by the tea-wither... The epitranscriptomic mark N6-methyladenosine(m^(6)A),which is the predominant internal modification in RNA,is important for plant responses to diverse stresses.Multiple environmental stresses caused by the tea-withering process can greatly influence the accumulation of specialized metabolites and the formation of tea flavor.However,the effects of the m^(6)A-mediated regulatory mechanism on flavor-related metabolic pathways in tea leaves remain relatively uncharacterized.We performed an integrated RNA methylome and transcriptome analysis to explore the m^(6)Amediated regulatory mechanism and its effects on flavonoid and terpenoid metabolism in tea(Camellia sinensis)leaves under solar-withering conditions.Dynamic changes in global m^(6)A level in tea leaves were mainly controlled by two m^(6)A erasers(CsALKBH4A and CsALKBH4B)during solar-withering treatments.Differentially methylated peak-associated genes following solarwithering treatments with different shading rates were assigned to terpenoid biosynthesis and spliceosome pathways.Further analyses indicated that CsALKBH4-driven RNA demethylation can directly affect the accumulation of volatile terpenoids by mediating the stability and abundance of terpenoid biosynthesis-related transcripts and also indirectly influence the flavonoid,catechin,and theaflavin contents by triggering alternative splicing-mediated regulation.Our findings revealed a novel layer of epitranscriptomic gene regulation in tea flavor-related metabolic pathways and established a link between the m^(6)A-mediated regulatory mechanism and the formation of tea flavor under solar-withering conditions. 展开更多
关键词 Camellia sinensis RNA methylation Epitranscriptome Secondary metabolite witherING
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乌龙头叶替代麦秸在肉羊育肥试验研究
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作者 马尚武 董俊 +3 位作者 刘佩雯 马甲平 刘锦年 丁俊莉 《饲料工业》 北大核心 2026年第1期197-200,共4页
为探究乌龙头枯叶作为粗饲料在肉羊养殖中的应用效果,试验选取体重相近[(20±5) kg]、体况良好的断奶湖羊公羔24只,随机分为4组,每组6只。用不同比例乌龙头叶粉替代当地日粮中麦秸,试验设对照组(0)、试验Ⅰ组(10%)、试验Ⅱ组(20%)... 为探究乌龙头枯叶作为粗饲料在肉羊养殖中的应用效果,试验选取体重相近[(20±5) kg]、体况良好的断奶湖羊公羔24只,随机分为4组,每组6只。用不同比例乌龙头叶粉替代当地日粮中麦秸,试验设对照组(0)、试验Ⅰ组(10%)、试验Ⅱ组(20%)和试验Ⅲ组(40%)4个组,预试期7 d,正试期90 d。结果表明:(1)乌龙头叶营养价值远高于麦秸,特别钙和粗脂肪含量高于麦秸366.67%和342.59%。(2)各组试验末重、采食量、体高、体长和胸围无显著差异(P>0.05);但试验Ⅰ、Ⅱ组平均日增重和胸围增长率显著高于对照组(P<0.05);试验Ⅰ、Ⅱ组料重比显著低于对照组。(3)试验Ⅱ组经济效益最高为112.59元,试验Ⅰ组收益为45.11元,试验Ⅲ组亏损34.42元,而对照组亏损55.26元。综合分析,乌龙头枯叶在肉羊日粮中应用前景广阔,特别20%替代麦秆对肉羊生长和经济效益最好。 展开更多
关键词 乌龙头枯叶 营养价值 肉羊 生长性能 育肥试验
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萎凋对白茶品质形成作用的研究进展
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作者 刘新宇 高英 +4 位作者 于淑伟 张晓佳 张杏民 梁美霞 宋鲁彬 《中国茶叶》 2026年第2期30-38,共9页
白茶作为中国传统六大茶类之一,萎凋工艺对其品质形成具有重要影响。文章系统梳理了萎凋条件与萎凋方式对白茶品质的影响,重点阐述了茶叶品质成分在萎凋过程中的变化规律,并深入解析了茶多酚、氨基酸、可溶性糖、咖啡碱及挥发性物质等... 白茶作为中国传统六大茶类之一,萎凋工艺对其品质形成具有重要影响。文章系统梳理了萎凋条件与萎凋方式对白茶品质的影响,重点阐述了茶叶品质成分在萎凋过程中的变化规律,并深入解析了茶多酚、氨基酸、可溶性糖、咖啡碱及挥发性物质等主要活性成分在此阶段的动态变化,以期为白茶加工过程中的品质调控提供理论依据。 展开更多
关键词 白茶 萎凋方式 活性成分转化 品质调控
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Metaphors of Despair and Enlightenment: A Case Study Based on Du Fu's Four Poems on Sick or Withered Trees
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作者 JIANG Yin 《Frontiers of Literary Studies in China-Selected Publications from Chinese Universities》 2024年第2期168-181,共14页
In the second year of the Shangyuan period(761),Du Fu wrote a quartet of poems on sick or withered trees.They are“The Sick Cypress,”“The Withered Palms,”“The Sick Orange Tree,”and“The Withered Nanmu Tree.”Diff... In the second year of the Shangyuan period(761),Du Fu wrote a quartet of poems on sick or withered trees.They are“The Sick Cypress,”“The Withered Palms,”“The Sick Orange Tree,”and“The Withered Nanmu Tree.”Different from his previous practice of using trees to embody personal aspirations,the poet employed sick or withered trees to allude social realities.These poems,rich with profound contemplation on individuals,society,and the Tang Dynasty,cover many important topics,such as the poet's bleak future,the decline of people's livelihoods,the immorality of rulers,and even the decline of the Tang Dynasty.These poems reveal his disappointment with the future of his country and his personal ambitions.This disenchantment reflects the pivotal shift in Du Fu's later thoughts,revealing the impetus behind his relinquishment of political aspirations in favor of poetic creation.In this regard,this quartet of poems is the most thought-provoking exploration,with an undeniable value among Du Fu's later works. 展开更多
关键词 Tang poetry Du Fu sick or withered trees DESPAIR ENLIGHTENMENT
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芽接和打顶时间对橡胶树籽苗芽接苗接穗萌发和生长的影响
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作者 唐敏 田海 +3 位作者 桂明春 李玲 梁国平 孙小龙 《热带作物学报》 北大核心 2025年第5期1145-1153,共9页
橡胶树(HeveabrasiliensisMull.Arg)籽苗芽接育苗法因具有育苗周期短、劳动强度低、单位面积育苗数量多、苗木主根发达等优势,被广泛应用于橡胶树优质种苗繁育。然而,秋冬季节芽接的橡胶树籽苗,芽接成活后接芽萌发所需的时间较长、芽接... 橡胶树(HeveabrasiliensisMull.Arg)籽苗芽接育苗法因具有育苗周期短、劳动强度低、单位面积育苗数量多、苗木主根发达等优势,被广泛应用于橡胶树优质种苗繁育。然而,秋冬季节芽接的橡胶树籽苗,芽接成活后接芽萌发所需的时间较长、芽接苗长势也较弱,这在很大程度上降低了橡胶树籽苗芽接育苗法的优势。因此,探究合适的配套技术措施以提高接穗萌发和生长速度至关重要。本研究以冬季芽接的橡胶树热研879籽苗为对象,系统比较了芽接和打顶时间对橡胶树籽苗芽接苗接穗的萌发和生长的影响。结果表明:(1)芽接时间对橡胶树籽苗芽接苗成活率、抽芽率、接穗苗高、出圃率4个生长指标影响显著(P<0.05),冬季11月芽接的苗木成活率、抽芽率以及出圃率均显著高于10月芽接的苗木,接穗生长至两蓬叶时的苗高则显著低于10月芽接。(2)打顶时间对橡胶树籽苗芽接苗接穗生长至两蓬叶时苗高影响显著,对芽接苗的成活率、抽芽率、回枯率、出圃率以及接穗茎粗均无显著影响。(3)芽接和打顶时间的交互作用对橡胶树籽苗芽接苗的成活率、抽芽率、回枯率、接穗生长量及出圃率均无显著影响。(4)冬季芽接的橡胶树籽苗宜采用带杆越冬策略,待翌年立春后2—3月打顶,可显著缩短接芽待萌发时间,减少砧木抹芽作业量,同时确保较高的接穗生长质量,且时间节点与当年种植期高度吻合,具有显著的实践价值。(5)对于砧木已生长至两蓬叶的籽苗芽接苗,采用在第一对真叶上方截砧的打顶方式,其打顶操作不影响成活率,且能将回枯率控制在4%以下,展现出良好的技术稳定性。基于上述研究结果,建议在生产实践中严格把控橡胶树籽苗芽接时间和相应打顶时间,确保砧木达到适宜生长状态再打顶;并适当调整管理措施,以获得最佳的育苗效果。本研究结果的应用将有助于提高橡胶树育苗的生产效率。 展开更多
关键词 橡胶树籽苗芽接 打顶时间 回枯率 出圃率
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Biochemical characterization of CsCXEs:Carboxylesterase enhances the biosynthesis of green odor volatiles during tea processing
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作者 Sanyan Lai Ning Yi +6 位作者 Shixin Yin Yipeng Huang Tianlin Shen Qianying Dai Liping Gao Xiaolan Jiang Tao Xia 《Horticultural Plant Journal》 2025年第4期1684-1698,共15页
Tea flavor is a comprehensive representation of its aroma and other characteristics.The formation of volatile odor compounds during tea processing depends on a variety of enzymatic and non-enzymatic activities.(Z)-3-h... Tea flavor is a comprehensive representation of its aroma and other characteristics.The formation of volatile odor compounds during tea processing depends on a variety of enzymatic and non-enzymatic activities.(Z)-3-hexenol is considered the primary source of the green odor and is also the most important component in tea aroma,significantly affecting the overall aroma.However,the biosynthesis and accumulation of(Z)-3-hexenol during tea processing have not been fully analyzed.In this study,we found that withering treatment at different times and withering plus shaking treatment at different degrees promoted the accumulation of important volatile components of green tea odor,especially(Z)-3-hexenol by GC-MS.The RNA-seq and qRT-PCR results showed that withering and withering plus shaking treatments enhanced the expression of(Z)-3-hexenol-related genes in tea leaves,including synthetic pathway 1 genes(CsLOX3,CsHPL1,CsADH4,and CsAHD1),synthetic pathway 2 genes(CsGLU),and synthetic pathway 3 genes(CsCXEs).Correlation analysis of the key odorants and important genes in the three synthetic pathways revealed that some CsCXEs were positively correlated with green odor compounds.The in vitro enzyme activity results showed that rCsCXE3(GWHTASIV011658),and rCsCXE6(GWHTASIV031480)exhibited hydrolytic activity against three tea acetate compounds[hexyl acetate,(E)-2-hexyl acetate,and(Z)-3-hexyl acetate],resulting in the production of corresponding alcohol compounds.In summary,withering and shaking treatment during tea processing promoted the expression of CsCXE3 and CsCXE6,thereby enhancing the production of hexenol compounds.These compounds play a crucial role in increasing the green odor of tea. 展开更多
关键词 Camellia sinensis CARBOXYLESTERASE ODOR Hydrolysis witherING SHAKING
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萎凋过程中环境胁迫对茶叶品质影响研究进展 被引量:4
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作者 晏朵 余鹏辉 龚雨顺 《茶叶科学》 北大核心 2025年第1期1-14,共14页
萎凋是茶叶品质形成的重要加工工序。萎凋期间茶鲜叶受到失水、温度、光照及机械损伤等多种环境胁迫,导致其发生复杂的生理生化变化,最终影响茶叶品质的形成。综述了茶叶萎凋过程中不同环境胁迫对茶叶主要品质(滋味与香气)形成的影响,... 萎凋是茶叶品质形成的重要加工工序。萎凋期间茶鲜叶受到失水、温度、光照及机械损伤等多种环境胁迫,导致其发生复杂的生理生化变化,最终影响茶叶品质的形成。综述了茶叶萎凋过程中不同环境胁迫对茶叶主要品质(滋味与香气)形成的影响,重点分析了不同环境胁迫如何调控茶鲜叶内化合物的合成与代谢,探讨了其影响茶鲜叶内细胞物理结构变化、酶促和非酶促化学反应内在作用机制,旨在为提高茶叶品质提供理论指导。 展开更多
关键词 萎凋 胁迫 茶叶品质
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不同萎凋方式对滇红茶香气物质的影响研究 被引量:1
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作者 吴亚敏 王兴华 +8 位作者 徐嘉忆 邓秀娟 雷金梅 杨芳 武天宇 周淼 袁文侠 张书珩 王白娟 《茶叶通讯》 2025年第1期52-60,共9页
为探究摇晾式萎凋、日光萎凋、复式萎凋、室内自然萎凋、加温萎凋对滇红茶香气物质的影响,选取‘云抗10号’春季一芽二叶鲜叶为原料,在其他工艺参数一致的情况下分别采用上述5种萎凋方式加工滇红茶,分别对茶样香气物质进行检测分析。结... 为探究摇晾式萎凋、日光萎凋、复式萎凋、室内自然萎凋、加温萎凋对滇红茶香气物质的影响,选取‘云抗10号’春季一芽二叶鲜叶为原料,在其他工艺参数一致的情况下分别采用上述5种萎凋方式加工滇红茶,分别对茶样香气物质进行检测分析。结果共检测出227种挥发性化合物,包括醇类58种、醛类36种、酮类23种、酸酯类59种、碳氢类42种、其他类9种,其中醇类物质占比最高;共有46种香气物质存在显著差异(p<0.05),且所有差异显著的醛类物质中摇晾式萎凋处理的占比均高于其他萎凋方式。相对气味活度值(Relative odor activity value,ROAV)分析结果表明ROAV≥0.1的物质有32种,其中19种物质的ROAV值存在显著差异(p<0.05)。不同萎凋方式虽然不能改变滇红茶香气的主体物质,但对香气物质的丰度及占比影响较大,尤其是摇晾式萎凋方式与其他萎凋方式差异显著。研究结果可为滇红茶的加工选择适宜的萎凋方式及高香型滇红茶的加工提供一定参考依据。 展开更多
关键词 红茶 茶叶加工 滇红 萎凋方式 GC-MS 香气
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不同萎凋处理对‘云抗10号’白茶品质的影响 被引量:1
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作者 周小慧 吴婷 +9 位作者 田迪 马晨阳 董蕊 李沅达 王祥 鲁倩 杨雪怡 肖雪 周红杰 李亚莉 《食品研究与开发》 2025年第7期23-32,48,共11页
为充分利用云南茶树鲜叶资源,以‘云抗10号’鲜叶(YKM-R)为原料,分别进行室内萎凋和复式萎凋加工白茶。利用感官审评、理化分析、顶空固相微萃取气质联用仪对两种白茶中的挥发性香气成分和非挥发性成分进行检测,并结合多元统计分析探究... 为充分利用云南茶树鲜叶资源,以‘云抗10号’鲜叶(YKM-R)为原料,分别进行室内萎凋和复式萎凋加工白茶。利用感官审评、理化分析、顶空固相微萃取气质联用仪对两种白茶中的挥发性香气成分和非挥发性成分进行检测,并结合多元统计分析探究两种不同工艺白茶的品质差异。结果表明,复式萎凋加工的‘云抗10号’白茶(YKM-L)的整体感官评分较高;两种白茶的茶多酚、咖啡碱和水浸出物含量存在显著差异(P<0.05);对挥发性香气成分进行检测,共鉴定出10类共97种共有挥发性香气成分。主成分分析(principal components analysis,PCA)和分级聚类算法(hierarchical cluster analysis,HCA)能明显地区分两种白茶,差异代谢物筛选结合香气活性值(odor activity value,OAV)分析显示,室内萎凋加工的‘云抗10号’白茶(YKM-T)较为突出的香气成分是具有甜香和花香特征的香叶醇、α-紫罗兰酮等,而YKM-L中较为突出的香气成分是具有果香特征的苯甲醛、β-环柠檬醛。 展开更多
关键词 ‘云抗10号’ 室内萎凋 复式萎凋 白茶品质 挥发性香气成分
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不同摊青工艺对恩施玉露咖啡碱及儿茶素含量的影响 被引量:1
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作者 陈俊轶 卢迪迪 +2 位作者 刘雨涵 刘哲 詹从红 《农业工程学报》 北大核心 2025年第3期318-326,共9页
为探索不同摊青工艺条件下恩施玉露的苦涩滋味变化及其呈味因子间相关性,该研究通过茶鲜叶摊青正交试验,结合高效液相色谱法(high-Performance liquid chromatography,HPLC)测定摊青后儿茶素类和咖啡碱含量,运用响应面法优化摊青工艺并... 为探索不同摊青工艺条件下恩施玉露的苦涩滋味变化及其呈味因子间相关性,该研究通过茶鲜叶摊青正交试验,结合高效液相色谱法(high-Performance liquid chromatography,HPLC)测定摊青后儿茶素类和咖啡碱含量,运用响应面法优化摊青工艺并建模,利用扫描电镜对茶叶微观结构进行讨论。结果表明:1)儿茶素总量在不同摊青条件下差异显著(P<0.05),而咖啡碱含量差异不明显(P>0.05);2)当初始含水率、摊青温度、摊青相对湿度、摊青风速分别为77.07%、25.49℃、60.24%、0.54 m/s时,酯型儿茶素与非酯型儿茶素比值(NETCAT/ETCAT)为0.5041,可达到去苦味的效果;3)相关性弦图显示NETCAT/ETCAT与表没食子儿茶素没食子酸酯(epigallocatechin gallate,EGCG)和表儿茶素没食子酸酯(epicatechin gallate,ECG)显著相关,其次为表没食子儿茶素(epigallocatechin,EGC),相关系数R分别为-0.990、-0.918及0.753。 展开更多
关键词 恩施玉露 摊青 儿茶素 咖啡碱 弦图
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茶叶萎凋过程中氨基酸和多酚在叶茎内的时空变化特征
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作者 程海燕 屠琳玥 +3 位作者 陈琳 徐安安 谢亨通 徐平 《茶叶科学》 北大核心 2025年第2期303-317,共15页
叶茎内的氨基酸和多酚在萎凋过程中的变化对于形成茶叶风味物质至关重要。系统解析了叶片和嫩茎中氨基酸和多酚的差异积累模式以及在萎凋过程中的变化特征。结果显示,在萎凋过程中叶片的酚氨比为4.66~6.36,高于嫩茎(1.97~2.59);嫩茎中... 叶茎内的氨基酸和多酚在萎凋过程中的变化对于形成茶叶风味物质至关重要。系统解析了叶片和嫩茎中氨基酸和多酚的差异积累模式以及在萎凋过程中的变化特征。结果显示,在萎凋过程中叶片的酚氨比为4.66~6.36,高于嫩茎(1.97~2.59);嫩茎中游离氨基酸总量显著高于鲜叶,嫩茎中游离氨基酸占干质量的7.44%,叶片中游离氨基酸占干质量的2.22%。鲜叶和嫩茎间存在44个差异积累的氨基酸及其衍生物,其中3个非蛋白质氨基酸(茶氨酸、氨基丁酸和豆叶氨酸)在嫩茎中高积累;叶片和嫩茎中茶多酚含量无显著差异,但存在97个差异积累的多酚类物质,酯型儿茶素和大部分黄酮及黄酮苷在叶片中相对高积累,而非酯型儿茶素在嫩茎中相对高积累。萎凋过程中叶片内游离氨基酸总量上升,而嫩茎中游离氨基酸总量持续下降,叶片和嫩茎中分别有21个和15个氨基酸类物质的含量在萎凋过程中显著变化;叶片和嫩茎中多酚总量变化趋势较为一致,分别存在49个和35个多酚类物质的含量在萎凋过程中显著变化。研究结果表明茶叶原料的叶茎比例对于后续加工中茶叶品质的形成具有重要影响,该研究为基于原料叶茎考量的萎凋调控技术开发提供了理论依据。 展开更多
关键词 代谢组学 萎凋 叶茎 游离氨基酸 茶多酚
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远红外辐射红茶萎凋过程品质变化规律及光谱-图像协同监测分析
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作者 夏高帆 马圣洲 +3 位作者 常惠林 李登珊 王雨 欧阳琴 《食品科学》 北大核心 2025年第24期9-17,共9页
本研究以茶鲜叶为原料,按照自然萎凋、远红外辐射3 h、远红外辐射6 h 3种工艺进行萎凋,测定主要滋味物质的含量,并采集萎凋样本的近红外光谱与图像数据,构建融合卷积注意力模块的一维卷积神经网络(onedimensional convolutional neural ... 本研究以茶鲜叶为原料,按照自然萎凋、远红外辐射3 h、远红外辐射6 h 3种工艺进行萎凋,测定主要滋味物质的含量,并采集萎凋样本的近红外光谱与图像数据,构建融合卷积注意力模块的一维卷积神经网络(onedimensional convolutional neural network with convolutional block attention module,CBAM-1DCNN)模型。结果显示,远红外辐射3 h条件下,萎凋15 h的酚氨比相比茶鲜叶下降了20.06%,感官得分最高。基于近红外光谱与机器视觉技术构建的CBAM-1DCNN模型比单一技术建立的模型判别能力更强,校正集准确率为99.11%,预测集准确率为96.00%。远红外辐射显著改变了主要滋味物质的含量,且通过近红外光谱与机器视觉技术可以实现红茶萎凋程度的快速判别。 展开更多
关键词 红茶萎凋 远红外辐射 近红外光谱 机器视觉 卷积神经网络
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基于非靶向代谢组学大叶种茶树白茶萎凋过程中代谢物变化轮廓分析
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作者 聂学滢 陈洪云 +5 位作者 罗梓文 曲浩 龙丽雪 刘本英 龙亚芹 陈林波 《茶叶通讯》 2025年第4期484-496,共13页
探究云南大叶种白茶萎凋过程代谢物变化规律以及相关代谢通路表达,挖掘大叶种白茶萎凋过程代谢物质的变化规律,采用大叶种‘矮丰’鲜叶为原料,利用非靶向代谢组学分析白茶加工过程差异代谢物。结果显示,代谢物主要在萎凋进程前24 h产生... 探究云南大叶种白茶萎凋过程代谢物变化规律以及相关代谢通路表达,挖掘大叶种白茶萎凋过程代谢物质的变化规律,采用大叶种‘矮丰’鲜叶为原料,利用非靶向代谢组学分析白茶加工过程差异代谢物。结果显示,代谢物主要在萎凋进程前24 h产生差异,其中种类最多的代谢物为脂肪酸类。在萎凋进程前24 h部分氨基酸及其衍生物含量增加、生物碱含量下降、黄酮类及其衍生物含量大部分降低,磷脂类含量呈下降趋势而游离脂肪酸含量呈增加趋势。结合代谢通路分析显示,亚油酸代谢相较于其他代谢途径更为显著,脂肪酸的代谢特征可能为白茶特殊香气的形成提供了一个信号。 展开更多
关键词 白茶 茶叶加工 萎凋 非靶向代谢组学 代谢物
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基于顶空固相微萃取、气相色谱-质谱结合相对香气活性值探究不同摊青温度对古丈毛尖绿茶香气物质的影响
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作者 陈诗怡 胡维霞 朱海燕 《食品与发酵工业》 北大核心 2025年第12期352-360,共9页
为探究摊青工艺中温度对古丈毛尖绿茶品质的影响,该研究分别设定摊青工艺中的温度(25、35、45℃)制作出T25(CK)、T35、T45茶样,采用顶空固相微萃取(headspace-solid phase microextraction,HS-SPME)结合气相色谱-质谱(gas chromatograph... 为探究摊青工艺中温度对古丈毛尖绿茶品质的影响,该研究分别设定摊青工艺中的温度(25、35、45℃)制作出T25(CK)、T35、T45茶样,采用顶空固相微萃取(headspace-solid phase microextraction,HS-SPME)结合气相色谱-质谱(gas chromatography-mass spectrometry,GC-MS)、相对香气活性值(relative odor activity value,ROAV)和感官审评的方法对古丈毛尖进行探究。结果表明,T35感官品质最佳,采用HS-SPME-GC-MS共鉴定出130种挥发性化合物。基于ROAV>1的筛选原则,分别在、T25(CK)、T35和T45中鉴定出33、32、33种关键香气化合物,其中变量重要性投影值>1的化合物共有11个,包括香豆素、正戊醇、柏木醇、2-乙基己醇、癸醛、苯甲醇、芳樟醇氧化物I、茉莉酸甲酯、正辛醛、香叶醛、乙酸乙酯,被认为是不同摊青温度处理制成的古丈毛尖绿茶香气关键差异化合物。该研究为古丈毛尖绿茶加工工艺优化、产品创新和品质提升提供了科学依据。 展开更多
关键词 绿茶 古丈毛尖 摊青温度 香气物质 HS-SPME-GC-MS ROAV
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