中国黑茶的起源与加工工艺

文章简述了四川黑茶、湖南黑茶、湖北老青砖、云南普洱以及广西六堡等黑茶的历史起源以及文化内涵,指出品质、工艺的独特性以及地域文化的差异造就了不同种类黑茶独特的发展历程;归纳总结了黑茶加工的基本工序及工艺,对比分析得出各地黑茶传统加工工艺的差异在于消费品质导向的不同以及精制过程中特色的紧压工序;结合品质调控以及规模化标准化生产的内在要求,提出对传统工艺的传承与创新以及机械化采制将是今后黑茶加工工艺改进的发展方向。     

不同加工工艺下‘紫娟’茶品质的比较

为研究不同加工工艺对‘紫娟’茶品质的影响,以‘紫娟’鲜叶为原料,分别利用烘青绿茶、晒青绿茶、红茶、白茶及黑茶的加工工艺制作成5种‘紫娟’茶,检测其主要品质成分的含量并进行系统分析。结果表明,不同加工工艺下,同一品种‘紫娟’鲜叶制得的茶样所含化学成分的含量差异较大。其中,‘紫娟’烘青绿茶中花青素含量最高,晒青绿茶次之;儿茶素的含量随着发酵程度的加深而降低。此外,在黑茶中没食子酸含量最高,在白茶中茶氨酸含量最高,而咖啡碱在红茶中的含量最高。由此可见,不同加工工艺对‘紫娟’茶的主要品质化学成分影响较大,其中‘紫娟’烘青绿茶的多酚类物质含量最为丰富。     

黑茶的发展简史

黑茶是六大茶类之一,为我国所特有。黑茶起源于四川粗边茶,开始以炒绿半干毛茶堆积做色、蒸压成团块成品茶;后来逐渐演变而发展到湖南安化的正规黑茶。黑茶湿看叶底褐色,汤色深橙黄而带红,香味有特殊风格,即不像绿茶,又不像黄茶,更不像青茶,品质有独立系统。凡品质与这个系统相近的茶叶都可以归纳为黑茶类,如湖南湘尖、茯砖、花砖,湖北老青茶,四川边茶,云南普洱茶以及广西六堡茶等,其花色品名繁杂,生产历史悠久。     

圣水黑茶出新品——千两茶

正继利用"黑毛茶"研制开发出"工艺茶砖"之后,近日湖北圣水茶场有限公司又从湖南安化请来一批专业技工,利用竹山县丰富的夏秋茶资源,加工出黑茶新品——千两茶。千两茶是湖南安化的一种传统名茶,其每卷茶叶净含量合老秤一千两,故名"千两茶";因其外表用篾篓包装成花格状,故又名"花卷茶"。该产品以存放多年的优质黑毛茶为原料,以竹篾、棕叶、寥叶等天然材     

相同加工原料下的六大茶类体外抗氧化性能比较

以春季茶树碧香早的一芽二叶茶鲜叶为原料,将其固定及分别加工成六大茶类,比较研究了相同加工茶鲜叶及其干茶质量下的六大茶类体外抗氧化性能,以期为茶叶新产品开发及健康消费提供科学依据。结果表明,固定样及六大茶类的还原能力和清除DPPH.、亚硝基、.OH及O2-.的能力均随茶汤浓度的增加而增强;固定样、绿茶、黄茶、黑茶、乌龙茶、白茶以及红茶对DPPH.的IC50依次为0.017、0.019、0.019、0.020、0.021、0.022和0.038mg干茶浸出物/ml,绿茶、固定样、乌龙茶、黑茶、白茶、黄茶和红茶对.OH的IC50依次为1.438、1.695、2.988、4.163、4.606、4.881和6.847mg干茶浸出物/ml,固定样、乌龙茶、黄茶、绿茶、白茶、黑茶和红茶对亚硝基的IC50依次为1.285、1.401、1.514、1.525、1.847、2.146和5.163mg干茶浸出物/ml。说明由相同原料加工而成的六大茶类在浸泡相同质量干茶的条件下,因其加工工艺的不同而在体外抗氧化性能上存在差异,固定样及六大茶类的抗氧化能力大小在总体上呈现不发酵茶(绿茶)＞半发酵茶(乌龙茶)＞全发酵茶(红茶)的趋势,其中以清除DPPH.的效果最好。     

黑茶品质成分及加工研究进展

黑茶作为中国六大茶类中的一种,近年来因其独特的保健作用及便于储藏、耐冲泡的特点而备受欢迎,其渥堆过程中微生物、渥堆工艺及保健作用等也被广泛研究。它是一种后发酵茶,经渥堆其生化成分发生一系列的化学反应,形成不同于其他茶类的独特风味。渥堆是黑茶加工中最关键的工序,其实质是以微生物活动为中心,在湿热、微生物以及胞外酶的相互作用下使多酚类物质自动氧化。综述黑茶某些品质成分,初加工中渥堆工艺、渥堆微生物及生化成分变化情况,初加工配套工艺技术以及深加工相关研究,概括黑茶目前的主要研究情况并展望今后黑茶的深入研究方向,即开展微生物、酶、品质成分三者间内在关联的研究,揭示黑茶特征风味形成机理,以及加工机械化、规模化、清洁化等研究,以期为黑茶的进一步研究提供基础和借鉴。     

“宿松香芽”茶加工工艺

宿松香芽高山优质茶,无公害产品,一直因没有统一的加工工艺导致茶叶的外形和品质差异大,不利于品质提高和市场销售,笔者通过多年来的生产实践,整理了“宿松香芽”茶加工工艺,对统一制作工艺和茶产业的发展有极大的促进作用.     

相同加工原料下的6类茶体外抗氧化性能比较

以春季茶树‘碧香早’的1芽2叶茶鲜叶为原料,选同一批次鲜叶采用蒸汽固样法将其制成固定样及加工成6类茶叶,并比较研究其体外抗氧化性能,以期为茶叶新产品开发及健康消费提供科学依据。结果表明,固定样及6类茶的还原能力和清除DPPH·、亚硝基、·OH及O2-·的能力均随茶汤浓度的增加而增强;固定样、绿茶、黄茶、黑茶、乌龙茶、白茶以及红茶对DPPH·的IC_(50)依次为0.017、0.019、0.019、0.020、0.021、0.022、0.038 mg(干茶浸出物)/mL,绿茶、固定样、乌龙茶、黑茶、白茶、黄茶和红茶对·OH的IC_(50)依次为1.438、1.695、2.988、4.163、4.606、4.881、6.847 mg(干茶浸出物)/mL,固定样、乌龙茶、黄茶、绿茶、白茶、黑茶和红茶对亚硝基的IC_(50)依次为1.285、1.401、1.514、1.525、1.847、2.146、5.163 mg(干茶浸出物)/mL。说明由相同原料加工而成的6类茶在浸泡相同质量干茶的条件下,因加工工艺不同而在体外抗氧化性能上存在差异,固定样及6类茶的抗氧化能力大小在总体上呈现不发酵茶(绿茶)半发酵茶(乌龙茶)全发酵茶(红茶)的趋势,其中以清除DPPH·的效果最好。     

高香型涌溪火青茶加工方法研究

为提高涌溪火青茶的加工香气品质,根据涌溪火青茶的加工工艺特点及乌龙茶加工所形成的品质风格,设计了高香型涌溪火青茶的加工方法。将鲜叶分开,一部分按乌龙茶加工工艺进行做青,另一部分鲜叶阴凉处摊放,按一定的比例与做青叶混匀,根据涌溪火青茶工艺完成后面的加工。结果表明：采用该加工方法,将14%~20%的鲜叶进行做青,制成的涌溪火青茶,有24种香气成分（共检出43种）相对含量差异达20%以上,其中15种占香气总量的5~6成;主要生化成分也有所变动,致使感官品质,特别是香气品质明显提升。3号样（做青叶比重1/7）综合评分高于传统工艺涌溪火青茶0.9和1.4分。     

黑茶的研究进展

黑茶的历史悠久,是我国六大茶类之一。由于黑茶是一种后发酵茶,经过渥堆而发生一系列的化学反应而形成独特滋味,备受人们喜爱,有广阔的发展前景。通过综述黑茶品质的成分与感官研究、黑茶加工工艺与加工过程中微生物的变化和安全性分析,概括黑茶保健功能和其香味成分的相关研究,揭示黑茶标准与黑茶认证、黑茶机械与黑茶营销的相关研究,旨在为黑茶的深层次研究提供理论基础。     

Location of a high-lysine gene and the DDT-resistance gene on barley chromosome 7

Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans.     

Biological Activity and Quantification of Suspected Allelochemicals from Alfalfa Plant Parts

Autotoxicity restricts reseeding of alfalfa (Medicago sativa L.) after alfalfa until autotoxic chemical(s) breaks down or is dispersed into external environments. A series of aqueous extracts from leaves, stems, roots and seeds of alfalfa ‘Vernal’ were bioassayed against alfalfa seedlings of the same cultivar to determine their autotoxicity. The highest inhibition was found in the extracts from the leaves. Extracts at 40 g dry tissue l^?1 from alfalfa leaves were 15.4, 17.5 and 28.7 times more toxic to alfalfa root growth than were those from roots, stems and seeds, respectively. A high‐performance liquid chromatography (HPLC) analysis with nine standard compounds showed that the concentrations and compositions of allelopathic compounds depended on the plant parts. In leaf extracts that showed the most inhibitory effect on root growth, the highest amounts of allelochemicals were detected. Among nine phenolic compounds assayed for their phytotoxicity on root growth of alfalfa, coumarin, trans‐cinnamic acid and o‐coumaric acid at 10^?3 m were most inhibitory. The type and amount of causative allelochemicals found in alfalfa plant parts were highly correlated with the results of the bioassay, indicating that the autotoxic effects of alfalfa plant parts significantly differed.     

Simultaneous Determination of Four Phenolic Acids in Radix Salviae Miltiorrhizae Formula Granules by QAMS

[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol...     

Changes in Seed Yield and Quality with Maturity in Onion (Allium cepa L., cv. 'Early Cream Gold')

Development of onion (Allium cepa L., cv. ‘Early Cream Gold’) seed under cool climate conditions in Tasmania, Australia occurred over a longer duration than previously reported, but similar patterns of change in yield components were recorded. In contrast to previous studies, umbel moisture content declined from 85 to 67 % over 57 days while seed moisture content decreased from 85 to 31 %. Seed yield continued to increase over the duration of crop development, with increasing seed weight compensating for seed loss resulting from capsule dehiscence in the later stages of maturation. Germination percentage was high and did not vary significantly from 53 to 77 days after full bloom (DAF), but mean germination time declined and uniformity of germination increased significantly over the same time period. The percentage abnormal seedlings declined with later harvest date, resulting in highest seed quality at 77 DAF. The results of this study suggest that the decision to harvest cool climate onion seed crops before capsule dehiscence will result in a loss of potential seed yield and quality.     

Pollen and pollination experiments. III. The viability of apple and pear pollen as affected by irradiation and storage

Summary Apple and pear pollen was irradiated with doses of 0, 50, 100, 250 and 500 krad (gamma rays) and stored at 4°C and 0–10% r.h. From the in-vitro germination percentages an average LD 50 dose of about 220 krad was estimated. For both irradiated and untreated pollen a close and corresponding lineair relationship existed between germination percentage and pollen tube growth.Irradiated pollen was much more sensitive to dry storage conditions than untreated pollen, resulting in less germination and more bursting. Apparently, irradiation caused the pollen cell membrane to lose its flexibility faster than normal. Rehydration of dry-stored, irradiated pollen in water-saturated air restored germination percentages up to their initial levels. The importance of this procedure in germination trials is stressed.     

Water Extraction Process of Chinese Herbal Compound Man Gan Ning

[Objectives]To optimize the water extraction process of Chinese Herbal Compound Man Gan Ning and establish a method for its extraction and content determination...     

Present status and future strategy in breeding faba beans (Vicia Faba L.) for resistance to biotic and abiotic stresses

Progress is being made, mainly by ICARDA but also elsewhere, in breeding for resistance to Botrytis, AScochyta, Uromyces, and Orobanche; and some lines have resistance to more than one pathogen. The strategy is to extend multiple resistance but also to seek new and durable forms of resistance. Internationally coordinated programs are needed to maintain the momentum of this work.Tolerance of abiotic stresses leads to types suited to dry or cold environments rather than broad adaptability, but in this cross-pollinated species, the more hybrid vigor expressed by a cultivar, the more it is likely to tolerate various stresses.     

Optimization of Extraction Technology and Determination of Content of Total Phenols of Leaves in Acanthopanax giraldii Harms

[Objectives] To determine the optimum extraction technology for total phenols of leaves in Acanthopanax giraldii Harms.[Methods]The single factor test and ortho...     

Cytoplasmic male sterility,resistance to gall mite and mildew,and season of leafing out in black currants

Summary Cytoplasmic male sterility (cms) is described in the F₁ hybrids Ribes × carrierei (R. glutinosum albidum × R. nigrum) and R. sanguineum × R. nigrum. In backcrosses to R. nigrum, progenies with R. glutinosum cytoplasm were either all male sterile, or segregated for full male fertility (F) and complete (S) and partial (I) male sterility. Ratios of F:I+S suggested that two linked genes controlled cms, F plants being dominant for one (Rf ₁) and recessive for the other (Rf ₂).Segregation for cms in relation to three linded genes, Ce (resistance to the gall mite, Cecidophyopsis ribes), Sph ₃(resistance to American gooseberry mildew, Sphaerotheca mors-uvae) and Lf ₁(one of two dominant additive genes controlling early season leafing out) indicated that Rf ₁and Rf ₂were in this linkage group. The gene order and approximate crossover values appeared to be: % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXafv3ySLgzGmvETj2BSbqef0uAJj3BZ9Mz0bYu% H52CGmvzYLMzaerbd9wDYLwzYbItLDharqqr1ngBPrgifHhDYfgasa% acOqpw0xe9v8qqaqFD0xXdHaVhbbf9v8qqaqFr0xc9pk0xbba9q8Wq% Ffea0-yr0RYxir-Jbba9q8aq0-yq-He9q8qqQ8frFve9Fve9Ff0dme% aabaqaciGacaGaamqadaabaeaafaaakeaacaWGdbGaamyzamaamaaa% baGaaiiiaiaacccacaGGWaGaaiOlaiaacgdacaGG0aGaaiiiaiaacc% caaaGaaiiiaiaacccacaGGGaGaamOuaiaadAgaliaaigdakmaamaaa% baGaaiiiaiaacccacaGGGaGaaiiiaiaaccdacaGGUaGaaiOmaiaacs% dacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaaaacaWGsbGaamOzaSGa% aGOmaOWaaWaaaeaacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaiaacc% cacaGGGaGaaiiiaiaacccaaaGaamitaiaadAgaliaaigdakmaamaaa% baGaaiiiaiaacccacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaiaacc% cacaGGGaGaaiiiaiaacccacaGGGaaaaiaadofacaWGWbGaamiAaSGa% aG4maaaa!6E4D!\[Ce\underline { 0.14 } Rf1\underline { 0.24 } Rf2\underline { } Lf1\underline { } Sph3\]. Crossover values of 0.36 for Ce-Lf ₁, and 0.15 for Lf ₁-Sph ₃were estimated from the relative mean differences in season of leafing out between seedlings dominant and recessive for Ce and Sph ₃.It is suggested that competitive disadvantage of lf ₁-carrying gametes and/or zygotes at low temperatures may be implicated in the almost invariable deficit of plants dominant for the closely linked mildew resistance allele Sph ₃. Poor performance of lf ₁- (and possibly lf ₂-) carrying gametes and young zygotes during periods of low temperature at flowering might also account for the liability of some late season cultivars and selections to premature fruit drop (running off).     

Screening techniques and sources of resistance to parasitic angiosperms

Parasitic angiosperms cause great losses in many important crops under different climatic conditions and soil types. The most widespread and important parasitic angiosperms belong to the genera Orobanche, Striga, and Cuscuta. The most important economical hosts belong to the Poaceae, Asteraceae, Solanaceae, Cucurbitaceae, and Fabaceae. Although some resistant cultivars have been identified in several crops, great gaps exist in our knowledge of the parasites and the genetic basis of the resistance, as well as the availability of in vitro screening techniques. Screening techniques are based on reactions of the host root or foliage. In vitro or greenhouse screening methods based on the reaction of root and/or foliar tissues are usually superior to field screenings and can be used with many species. To utilize them in plant breeding, it is necessary to demonstrate a strong correlation between in vitro and field data. The correlation should be calculated for every environment in which selection is practiced. Using biochemical analysis as a screening technique has had limited success. The reason seems to be the complex host-parasite interactions which lead to germination, rhizotropism, infection, and growth of the parasite. Germination results from chemicals produced by the host. Resistance is only available in a small group of crops. Resistance has been found in cultivated, primitive and wild forms, depending on the specific host-parasite system. An additional problem is the existence of pathotypes in the parasites. Inheritance of host resistance is usually polygenic and its transfer is slow and tedious. Molecular techniques have yet to be used to locate resistance to parasitic angiosperms. While intensifying the search for genes that control resistance to specific parasitic angiosperms, the best strategy to screen for resistance is to improve the already existing in vitro or greenhouse screening techniques.