闽北夏暑乌龙茶加工过程中生化成分的变化及其品质分析

以闽北茶区的水仙、肉桂、梅占夏署季节茶鲜叶为原料,分析了三个品种夏暑乌龙茶的品质特征及其生化成分在加工过程中的变化,为有效利用夏暑茶资源和提高夏暑乌龙茶的品质提供参考.结果表明,三个品种夏暑茶鲜叶各生化成分含量较丰富,品种间各生化成分的含量存在差异;加工过程中水浸出物、茶多酚、咖啡碱的含量减少,氨基酸含量有所增加,但不同品种各生化成分减少或增加的幅度不同;毛茶感官审评综合得分高低依次为：肉桂（86.38）＞梅占（82.48）＞水仙（82.20）,其中肉桂具有较好的乌龙茶品质特征,且与梅占、水仙的品质差异达极显著水平.     

不同做青风格安溪铁观音“音韵”的感官审评及品质化学比较

为探讨安溪铁观音＂音韵＂的感官品质及其化学特征,对3种不同做青风格的安溪铁观音样品进行感官审评,并对其主要品质成分进行常规测定与高效液相色谱法（HPLC）测定。结果表明：＂正做型＂铁观音,其酯型儿茶素总量较高、游离氨基酸总量较低、酚氨比较高,其外形乌润紧结、香气幽长沉香、汤色金黄明亮、滋味醇厚高爽、叶底金黄肥软,＂音韵＂醇而幽长;＂消青型＂铁观音,其游离氨基酸总量较中等、酯型儿茶素总量中等、酚氨比中等,其外形翠绿圆结、香气浓郁鲜香、汤色黄绿明亮、滋味鲜爽甘甜、叶底绿黄软亮,＂音韵＂厚而鲜爽;＂拖酸型＂铁观音,其游离氨基酸总量较高、酯型儿茶素总量较低、酚氨比较低,其外形乌绿润圆结、香气高锐鲜酸、汤色杏黄明亮、滋味鲜酸甘爽、青绿微暗,＂音韵＂锐而鲜爽。因此,这3种不同做青风格的铁观音,其外形和内质都有较为典型的品质特征,可以适应茶叶市场上不同消费人群的需求。     

Volatile profile analysis and quality prediction of Longjing tea (Camellia sinensis) by HS-SPME/GC-MS

This study aimed to analyze the volatile chemical profile of Longjing tea, and further develop a prediction model for aroma quality of Longjing tea based on potent odorants. A total of 21 Longjing samples were analyzed by headspace solid phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). Pearson’s linear correlation analysis and partial least square (PLS) regression were applied to investigate the relationship between sensory aroma scores and the volatile compounds. Results showed that 60 volatile compounds could be commonly detected in this famous green tea. Terpenes and esters were two major groups characterized, representing 33.89% and 15.53% of the total peak area respectively. Ten compounds were determined to contribute significantly to the perceived aroma quality of Longjing tea, especially linalool (0.701), nonanal (0.738), (Z)-3-hexenyl hexanoate (−0.785), and β-ionone (−0.763). On the basis of these 10 compounds, a model (correlation coefficient of 89.4% and cross-validated correlation coefficient of 80.4%) was constructed to predict the aroma quality of Longjing tea. Summarily, this study has provided a novel option for quality prediction of green tea based on HS-SPME/GC-MS technique.     

不同干旱程度下外源茉莉酸甲酯对水稻抗旱性的影响

茉莉酸甲酯（MeJA）是与抗性密切相关的植物生长物质,本研究探讨了它在不同干旱程度的胁迫条件下,施加不同浓度的MeJA对水稻抗旱性的诱导效应。结果表明,随着水分胁迫的加深,水稻遭受伤害随之加剧,水稻叶片中各生理生化指标均有相应的变化,叶片水势,丙二醛MDA含量,电导率及脂氧合酶（LOX）活性都显著增加。施加MeJA后,水稻遭受胁迫的程度有所缓解,不过在高度干旱情况下,MeJA并不能使水稻完全恢复到对照水平,水稻仍然遭受一定程度的伤害,其中,浓度较小（0．25μM）的MeJA处理使水稻恢复较多,可以认为是增强水稻抗旱性的较适宜浓度。     

茶叶香气成分的研究--乌龙茶与鲜茶香气成分的比较

报道了用同时蒸馏-萃取装置分别提取乌龙茶与鲜茶香气成分，测得乌龙茶的香气成分含量为3．65％．鲜茶的香气成分含量为2．40%。用GC／MS法分别从乌龙茶与鲜茶香气成分中分离并确定出42种和19种化学成分，并对香气化学成分及含量进行了对比。     

茶寄生中茶多酚含量的分析

对茶寄生中茶多酚的含量进行分析．茶多酚是混合物,由于各种茶多酚结构相似,较难分离．没食子酸（EC）、表没食子儿茶素（EGC）、没食子儿茶素没食子酸酯（EGCG）、表儿茶素没食子酸酯（ECG）4种茶多酚是茶叶中茶多酚的主要成分．本研究采用高效液相色谱（ HPLC）法同时测定了EC、EGC、EGCG、ECG 4种茶多酚,4种茶多酚在15 min内达到有效分离,方法的变异系数小于0．0360％,回收率为95．2％～104．2％．实验结果表明,茶寄生样品中只含有茶多酚中的EGC,其中云南粗茎茶寄生样品中的EGC含量略高于云南细茎茶寄生样品中EGC含量．     

不同采摘标准和做青强度对乌龙茶的生化成分变化和品质的影响

以紫阳群体种茶树鲜叶为试材,以铁观音品种茶树鲜叶为对照（CK）,研究了采摘标准和做青强度对乌龙茶的生化成分变化和品质的影响。结果表明,各采摘标准的茶树鲜叶生化成分含量差异显著,以小开面最丰富,中开面次之、大开面最差;加工过程中茶多酚、水浸出物、咖啡碱的含量减少,氨基酸有所增加;茶多酚和水浸出物持续减少,做青强度越大减少幅度越大,氨基酸和咖啡碱的增减变化还与鲜叶原料有关。各处理之间成茶感观品质差异显著,所有处理除了小开面重做青茶样与CK品质差异不显著外,其他均与CK差异显著。还提出了利用紫阳群体种茶树鲜叶进行乌龙茶加工的工艺。     

Regulation of autophagy by tea polyphenols in diabetic cardiomyopathy

Objective

To investigate the effect of tea polyphenols on cardiac function in rats with diabetic cardiomyopathy, and the mechanism by which tea polyphenols regulate autophagy in diabetic cardiomyopathy.

Methods

Sixty Sprague-Dawley (SD) rats were randomly divided into six groups: a normal control group (NC), an obesity group (OB), a diabetic cardiomyopathy group (DCM), a tea polyphenol group (TP), an obesity tea polyphenol treatment group (OB-TP), and a diabetic cardiomyopathy tea polyphenol treatment group (DCM-TP). After successful modeling, serum glucose, cholesterol, and triglyceride levels were determined; cardiac structure and function were inspected by ultrasonic cardiography; myocardial pathology was examined by staining with hematoxylin-eosin; transmission electron microscopy was used to observe the morphology and quantity of autophagosomes; and expression levels of autophagy-related proteins LC3-II, SQSTM1/p62, and Beclin-1 were determined by Western blotting.

Results

Compared to the NC group, the OB group had normal blood glucose and a high level of blood lipids; both blood glucose and lipids were increased in the DCM group; ultrasonic cardiograms showed that the fraction shortening was reduced in the DCM group. However, these were improved significantly in the DCM-TP group. Hematoxylin-eosin staining showed disordered cardiomyocytes and hypertrophy in the DCM group; however, no differences were found among the remaining groups. Transmission electron microscopy revealed that the numbers of autophagosomes in the DCM and OB-TP groups were obviously increased compared to the NC and OB groups; the number of autophagosomes in the DCM-TP group was reduced. Western blotting showed that the expression of LC3-II/I and Beclin-1 increased obviously, whereas the expression of SQSTM1/p62 was decreased in the DCM and OB-TP groups (P<0.05).

Conclusions

Tea polyphenols had an effect on diabetic cardiomyopathy in rat cardiac function and may alter the levels of autophagy to improve glucose and lipid metabolism in diabetes.

     

泰山女儿茶的儿茶素含量测定

为了同时测定女儿茶中4种儿茶素（DC,EC,GC和EGC）及咖啡因（CAF）,对女儿茶质量评判奠定基础,笔者采用伊利特C18（250mm×4.6mm）色谱柱,甲醇-水-乙酸为流动相,流速1ml/min,检测波长278nm,在所选用条件下,各组分理想分离,效果良好。     

Comparison of volatile profiles and bioactive components of sun-dried Pu-erh tea leaves from ancient tea plants on Bulang Mountain measured by GC-MS and HPLC

Journal of Zhejiang University-SCIENCE B - To explore the volatile profiles and the contents of ten bioactive components (polyphenols and caffeine) of sun-dried Pu-erh tea leaves from ancient tea...     

应用固相微萃取技术检测茶汤中的菊酯类农药残留

探讨了单壁碳纳米管SPME纤维的制备,并应用SPME/GC技术直接检测茶汤中的菊酯类农药残留.该方法在优化的条件下,6种菊酯类农药的检测限为0.01-0.05ng/mL,线性范围0.1-50.0ng/mL.相关系数R2在0.96以上,相对标准偏差为4.1-11.7%.所建立的SPME/GC法具有分析速度快、无需任何有机溶剂、灵敏度高等特点,在茶汤中菊酯残留的快速分析领域应具有较好的应用前景.     

SPME／GC—MS法分析柠檬草挥发气体成分

利用固相微萃取SPME／GC—MS技术分析了柠檬草的挥发气体成分。结果表明：柠檬草中共鉴定出25种主要挥发性化合物,以碳氢化合物和醛类物为主,包括β-月桂稀（34．34％）、石竹烯（0．493％）、莰烯（0．646％）、D-柠檬烯（0．126％）、1R-α-蒎烯（0．73％）、柠檬醛（26．5％）、3,7二甲基-2,6-辛二稀醛（26．63％）等。经过精制的柠檬草精油含有酮和烃类化合物,主要有：2-十一酮（0．606％）、2-甲基-5-（1-甲基乙基）环己酮（1．83％）、（1S）-6,6-二甲基-二乙基二环-[3,1,1]-庚烷,（0．34％）、1,4-双亚甲基-环已烷,（0．176％）,3-丙基-环已基（0．1667％）。     

Yield and quality responses of citrus （Citrus reticulate） and tea （Podocarpusfleuryi Hickel.） to compound fertilizers

Experiments were carried out with citrus （Citrus reticulate） and tea （Podocarpus fleuryi Hickel.） to study the effects of compound fertilizers on their yields and quality. In the citrus experiment, application of compound fertilizers increased available P K and Mg contents in soil but decreased alkali-hydrolyzable N contents in soil and N, P and K contents in leaves. In the tea experiment, application of compound fertilizers increased available P, K and Mg contents in soil and N, P, K and Mg contents in leaves but decreased alkali-hydrolyzable N in soil compared with the urea treatment. Application of compound fertilizers could improve the quality of citrus and tea, increase their yields and enhance their economical profits significantly. Compared with the control, application of compound fertilizers increased citrus yields by 6.31, 12.94 and 17.69 t/ha, and those of tea by 0.51,0.86 and 1.30 t/ha, respectively. Correspondingly, profits were increased by 21.4% to 61.1% for citrus and by 10.0% to 15.7% for tea. Optimal rates of compound fertilizers were recommended for both crops.     

三种不同制作工艺的铁观音茶香气组分比较分析

采用顶空固相微萃取技术（HS-SPME）提取3种不同制作工艺的铁观音茶中香气成分,用气相色谱-质谱法（GC/MS）从正炒工艺加工的铁观音茶中鉴定出8种化合物,消青工艺加工的铁观音茶中鉴定出7种化合物,拖酸工艺加工的青茶中鉴定出10种化合物.     

不同温度处理对冷泡茶主要成分溶出速度的影响

采用常温、-18℃、-40℃处理茶鲜叶,参考绿茶的炒制工艺制成茶叶,分别室温水冲泡,测定茶汤中茶多酚,茶氨酸,咖啡因的溶出速度的影响,确定冷泡茶加工工艺。结果表明：-40℃冷冻的茶叶中茶多酚、茶氨酸、咖啡因溶出速度比-18℃冷冻的茶叶快,常温处理溶出最慢。     

普洱茶的茶多酚和氨基酸冲泡浸出规律研究

通过对普洱茶的特级、三级、九级三个茶样进行五分钟沸水冲泡处理,测出相应的茶多酚和游离氨基酸含量．探讨普洱茶在冲泡过程中,茶多酚和游离氨基酸的浸出规律．研究表明：随着级别的降低,茶多酚和氨基酸含量明显减少;随着冲泡次数的增加,茶多酚和氨基酸的浸出含量也随之减少．     

阴香叶挥发性物质的GC／MS分析

利用顶空固相微萃取技术（SPME）吸附采集阴香叶的挥发性物质,采用气相色谱-质谱（GC／MS）技术对其进行分析研究．结果显示,从阴香叶中鉴定出39种化学物质,占挥发性物质总量的98．48％,其主要挥发性物质为龙脑（19．68％）、桉树脑（10．49％）、乙酸双环【2．2．1】庚-2-基酯（9．65％）、α-蒎烯（7．36％）、D-柠檬烯（6．45％）、石竹烯（5．80％）等,这些物质的共同作用形成了阴香叶特殊的香味．     

苦荆茶茶汤变色原因的初步研究

采用紫外-可见光吸收光谱分析法分析了用蒸馏水、自来水、含钙水以及偏酸和偏碱的水冲泡苦荆茶后的茶汤,发现泡茶水的pH值与茶汤的颜色变化有直接关系。经红外吸收光谱分析鉴定茶汤变色物质的基团特性,初步认为引起苦荆茶茶汤变色的物质是多酚类物质。该类物质可能在呈弱碱性的自来水环境中与茶叶自身所含的矿物质或自来水中的Ca^2＋、Mg^2＋形成有色的物质致使茶汤变色。该研究结果对苦荆茶的加工和产品开发具有实践意义。     

北五味子叶挥发油化学成分分析

利用同时蒸馏-萃取装置提取北五味子叶挥发油,其提取率为5.05%,并用气相色谱-质谱联用仪对北五味子叶挥发油化学成分进行分析鉴定.从分离到的132个成分中,鉴定出68个成分,占挥发油总含量的53.84%,其中主要成分为1-乙烯基-1-甲基-2,4-二（丙-1-烯-2-基）环己烷（6.33%）,2,6-二甲基-6-（4-甲基-3-戊烯基）-双环[3.1.1]庚-2-烯（4.40%）和1-甲基-5-亚甲基-8-（1-甲乙基）-1,6-环癸二烯（3.98%）.     

古茶园茶贮藏的品质变化研究

云南省分布着大量的古茶园,普洱市澜沧县惠民古茶园是典型的栽培型古茶园,约有130年,古茶园的茶具有美好的香气和品质特征,被普洱市当地人奉为上品,特别是在自然环境下贮藏几年后,香气和优良的品质特征更为明显,为揭示古茶园茶香气和品质特征的变化,让人们进一步了解、认识普洱茶;采用感官审评和化学分析手段,对古茶园茶的外形、颜色、滋味、香气等进行审评和测定。贮藏在自然环境下1～6年,汤色由淡黄色变为红黄色,地域香变为淡淡陈香,滋味由微苦涩纯正味长回甘变为入口微涩微苦、舌底微涌泉、醇感、滑顺、味长、纯正;可溶性糖、黄酮类化合物、TR和TB分别增加0．5％、4．96％、0．565％和0．395％;茶多酚、咖啡碱、游离氨基酸和TF分别减少6．13％、2．63％、1.04％和0．068％。为普洱茶的研究提供数据．便于古茶园茶能更好的加以利用。