紫芽品种茶树芽叶多酚类物质组成特征

通过测定茶树特异性紫芽品种芽叶的茶多酚、儿茶素及其各组分、黄酮类、花青素的含量,探讨紫芽品种芽叶中多酚类物质组成上的差异。结果表明,紫芽品种茶树芽叶中的花青素含量与芽叶紫色深浅关系密切,芽叶紫色程度越深,花青素含量越高。深紫品种的花青素含量约为浅紫品种的5倍,常规品种紫色芽叶中的花青素含量为其正常黄绿色芽叶的2．46倍。紫芽品种茶树芽叶中的茶多酚总量、黄酮类、儿茶素总量及儿茶素各组分的含量与芽叶紫色深浅均无直接关系。     

紫芽品种茶树春梢芽叶生化成分分析

研究了紫色深浅不一的5个特定紫芽品种茶树春梢芽叶中的花青素、茶多酚、黄酮类、氨基酸、咖啡碱、水浸出物、儿茶素总量、酯型儿茶素总量、简单儿茶素总量等生化成分含量的差异。结果表明,紫芽品种茶树芽叶深浅与花青素含量关系密切,与茶多酚、咖啡碱、氨基酸、     

茶树紫色芽叶的呈味特征及降低苦涩味的研究

茶树群体品种常见的紫色芽叶所制成的绿茶苦涩味明显。分离测定了茶树紫色芽叶主要苦涩味特征成分,用苦涩味阈值和苦涩味指数定量评价了各成分的呈味特征。结果表明,茶树紫色芽叶花青素含量高达1.14%,紫色芽叶中花青素和儿茶素的含量分别是绿色芽叶的57倍和1.13倍,花青素和儿茶素含量较高是其苦涩味较强的主要原因。茶叶苦涩味成分阈值的大小顺序为:咖啡碱(0.30)<花青素(0.40)<儿茶素(0.80);以苦涩味指数评价成分对紫色芽叶苦涩味实际影响大小顺序为:儿茶素(3.32)>咖啡碱(2.13)>花青素(0.57)。研究还表明,在紫色芽叶加工绿茶的过程中,添加约0.2%的酪蛋白具有降低苦涩味的作用,可使品质得到改善,使茶汤中多酚类浓度降低19.5%,苦涩味指数由3.70降至2.98,由此提供了一种降低紫色芽叶苦涩味的技术途径。采用多酚-蛋白复合反应模型,提出了用相对沉淀率(RA)作为酪蛋白对多酚类物质的苦涩味抑制能力的评价指标。     

云南稀有茶树品种“紫娟＇’的植物学特性和品质特征

稀有茶树品种“紫娟”新梢芽叶呈紫芽、紫叶、紫茎,加工制品,茶汤水色亦为紫色,香气郁香独特,叶底呈靛青色。适宜云南主产茶区种植。黄酮类、锌、花青素和EGC含量比云南大叶种茶高。花青素含量约为一般红芽茶的3倍。经动物试验表明其降压效果优于云南大叶种茶。     

云南稀有茶树品种"紫娟"的植物学特性和品质特征

稀有茶树品种"紫娟"新梢芽叶呈紫芽、紫叶、紫茎,加工制品,茶汤水色亦为紫色,香气郁香独特,叶底呈靛青色.适宜云南主产茶区种植.黄酮类、锌、 花青素和EGC含量比云南大叶种茶高.花青素含量约为一般红芽茶的3倍.经动物试验表明其降压效果优于云南大叶种茶.     

“红紫芽”茶树新品系的生物学特性研究

对全年芽叶都呈红紫色的10个新选育的茶树品系进行系统的生物学性状调查和生化组分分析。结果表明:新品系属乔木或小乔木型,生长势强;芽叶红紫色的深浅与花青素的含量呈正相关;除丹凤和红叶4号芽叶色泽分别在春季和秋季最深外,其他红紫芽品系芽叶的红紫色都在夏季最深,说明"红紫芽"茶树芽叶的色泽及其花青素含量同时受外界环境和遗传因子的控制。     

紫芽茶研究进展

近年来,随着科学研究的深入,造成茶树红紫芽现象的主要组分花青素的医疗保健功能被逐渐证明,选育稳定遗传的红紫芽茶树品种以及红紫芽茶的加工成为当前茶树新品种开发利用的热点。紫娟为可稳定遗传紫色芽叶性状的新品种茶树资源,有关其主要生化成分、保健功能的研究已有不少,它的育成有力推动了紫化茶树品种的选育以及紫芽茶相关领域的研究。本文综述了紫芽茶在生理生化、适制性、特色产品开发,以及保健功能等方面的研究进展,以期为特色茶树种质资源的进一步创新利用提供参考。     

红芽直立茶紫色叶形成机制的转录组分析

云南具有丰富的茶树资源,紫芽茶树是其中重要的一种。红芽直立茶具有典型的紫色芽叶,富含花青素,是重要的特异茶树种质资源。本研究通过转录组技术对红芽直立茶的不同叶色进行研究,筛选到8779个差异表达基因,GO和KEGG富集结果显示,差异基因涉及到多个色素形成及积累的功能。构建茶叶中类黄酮和类胡萝卜素生物合成两个途径,紫色叶中大量合成黄酮类化合物的关键基因上调,与茶叶紫色的形成密切相关。同时,紫色叶中类胡萝卜素的生物合成受到抑制,紫色叶具有更好的抗衰老能力。本研究将有助于对茶树紫色叶形成机制的认识,为特色茶育种研究奠定基础。     

茶树紫色芽叶花青苷组分分析及结构推测

通过筛选流动相、优化洗脱梯度,建立了茶树紫色芽叶花青素HPLC的分析方法,并从提取的花青素粗制品中分离出9个主要色谱峰;运用HPLC-DAD-MS/MS联用技术,获得了其中7个组分的紫外-可见光谱信息、质谱数据,结合文献资料,初步推测了茶树紫色芽叶花青素中5个主要组分,分别为：飞燕草-3-半乳糖苷、矢车菊-3-半乳糖苷、飞燕草-3-芸香糖苷、矢车菊-3-芸香糖苷和天竺葵-3-芸香糖苷,此外,采用外标法对各组分进行了定量分析,并获得了粗提物,纯度为32%。该方法简便快捷,重现性好,可用于茶树紫色芽叶中花青素组分的分析与鉴定。     

茶树紫色芽叶的绿茶适制性研究

以湖南农业大学长安教学基地的茶树群体品种芽叶为材料,运用高效液相色谱、常规理化分析与感官审评等方法,以正常芽叶为对照对紫色芽叶绿茶适制性进行了研究.结果表明,由紫色芽叶加工而成的绿茶样的多酚类含量、水浸出物含量均高于对照,感官品质在外形及香气方面显著优于对照.综合结果显示紫色芽叶加工绿茶具有一定的适制性.     

Mineral composition of some traditional Mexican teas

Teas of plant origin traditionally consumed by the Mountain Pima of Chihuahua, Mexico, were analyzed for mineral nutritional content. Fe, Cu, Zn, Ca, and Mg composition was determined for native teas made from shoots ofTagetes lucida, T. filifolia, Elytraria imbricata, andHolodiscus dumosus, and from root xylem ofCeanothus depressus andPhaseolus ritensis. Native uses of these teas are also described.     

Studies on natural repellents against potato tuber moth (Phthorimaea operculella Zeller) in country stores

Summary The effects of the leaves of five plant species, one from each of the generaAmbrosia, Anemone, Eupatorium, Eucalyptus andLantana, on potato tuber moth were investigated under indigenous storage conditions at the Central Potato Research Station, Shillong (1800 m above sea level). Their action was compared with that of a biological insecticide (spores ofBacillus thuringiensis), a chemical insecticide (carbaryl), and an untreated control. The data collected after six months storage on tuber damage, sprout damage and the rotting indicated that the leaves ofLantana aculeata provided most protection to the tubers, reducing damage from over 70% in the check to below 5%, and sprout damage from over 45% to below 3%. Next best wasEucalyptus globulus followed byB. thuringiensis. They may be used on tubers stored for table use or for seed as they had no adverse effect on germination or on the yield of a subsequent crop.     

Comparative Assessment of the Efficacy of Various Nitrogen Fertilizers

Summary

The efficiency of N fertilizers is usually poor; often less than 50% of the applied N is taken up by the crop. This review focuses on various N fertilizers with respect to the significance of different N loss pathways, namely (i) ammonia volatilization, (ii) dinitrogen and nitrogen oxide emissions, and (iii) nitrate leaching. Further, the significance of biological N immobilization, ammonium fixation and, finally, the impact of nitrate vs. ammonium uptake on crop yield are also discussed. The reviewed literature shows that N fertilizers may differ markedly in their susceptibility to losses. There is, however, considerable scope to improve N efficiency of each N source by proper N management practices.     

Redox Status and Neuro Inflammation Indexes in Cerebellum and Motor Cortex of Wistar Rats Supplemented with Natural Sources of Omega-3 Fatty Acids and Astaxanthin: Fish Oil,Krill Oil,and Algal Biomass

Health authorities worldwide have consistently recommended the regular consumption of marine fishes and seafood to preserve memory, sustain cognitive functions, and prevent neurodegenerative processes in humans. Shrimp, crabs, lobster, and salmon are of particular interest in the human diet due to their substantial provision of omega-3 fatty acids (n-3/PUFAs) and the antioxidant carotenoid astaxanthin (ASTA). However, the optimal ratio between these nutraceuticals in natural sources is apparently the key factor for maximum protection against most neuro-motor disorders. Therefore, we aimed here to investigate the effects of a long-term supplementation with (n-3)/PUFAs-rich fish oil, ASTA-rich algal biomass, the combination of them, or krill oil (a natural combination of both nutrients) on baseline redox balance and neuro-inflammation indexes in cerebellum and motor cortex of Wistar rats. Significant changes in redox metabolism were only observed upon ASTA supplementation, which reinforce its antioxidant properties with a putative mitochondrial-centered action in rat brain. Krill oil imposed mild astrocyte activation in motor cortex of Wistar rats, although no redox or inflammatory index was concomitantly altered. In summary, there is no experimental evidence that krill oil, fish oil, oralgal biomass (minor variation), drastically change the baseline oxidative conditions or the neuro-inflammatory scenario in neuromotor-associated rat brain regions.     

Potential of dry fractionation of wheat bran for the development of food ingredients,part II: Electrostatic separation of particles

Wheat bran is a composite material made of several layers, such as pericarp, testa and aleurone. It could be fractionated into purified fractions, which might either be used as food ingredients, or serve as a starting material for extraction of bioactive compounds. The aim of this work was to evaluate the potential of using electrostatic separation as a way to obtain purified fractions from wheat bran. Ultrafine-ground bran obtained either by cryogenic grinding or by grinding at ambient temperature was used as starting material. The ultrafine bran was then charged by tribo-electrification and introduced in a chamber containing two high voltage electrodes, where bran particles were separated depending on their acquired charge, allowing positively and negatively charged fractions to be collected separately. The particle size distribution, microstructure and biochemical composition of the obtained fractions were studied. The charge of the particles was influenced by their biochemical composition: particles rich in highly branched and cross-linked arabinoxylans (pericarp) were separated from particles rich in β-glucan, ferulic acid and para-coumaric acid (aleurone cell walls). The testa and the intracellular compounds from aleurone were not highly charged, neither positively nor negatively. The most positively charged fraction represented 34% of the initial bran, and contained 62% of the ferulic acid present in the initial bran. The yield of the separation process was good (5.4% loss), and could be further increased.     

In vitro antimicrobial activity of different accessions ofSolanum commersonii Dun. from Uruguay

Summary The in vitro antimicrobial activity of extracts from accessions ofSolanum commersonii Dun. collected in the south of Uruguay was investigated against five microorganisms including the pathogenRalstonia solanacearum. A total of 30 extracts corresponding to organic and aqueous extracts were studied. Interestingly, most of the positive results for growth inhibition were againstR. solanacearum. The extracts were also analyzed for the presence of glycoalkaloids and lectins. Six of the ten aqueous extracts showed lectin presence and a wide variation in the type and amounts of glycoalkaloids, was found. Results indicate that there is no clear relationship between the antimicrobial activity against the five microorganisms screened and the presence or amounts of lectins and glycoalkaloids, traditionally regarded as possible antimicrobial metabolites in theSolanum genus, which indicates the presence of as yet unidentified antimicrobial compounds.     

Pharmacokinetics of Marine-Derived Drugs

Marine organisms represent an excellent source of innovative compounds that have the potential for the development of new drugs. The pharmacokinetics of marine drugs has attracted increasing interest in recent decades due to its effective and potential contribution to the selection of rational dosage recommendations and the optimal use of the therapeutic arsenal. In general, pharmacokinetics studies how drugs change after administration via the processes of absorption, distribution, metabolism, and excretion (ADME). This review provides a summary of the pharmacokinetics studies of marine-derived active compounds, with a particular focus on their ADME. The pharmacokinetics of compounds derived from algae, crustaceans, sea cucumber, fungus, sea urchins, sponges, mollusks, tunicate, and bryozoan is discussed, and the pharmacokinetics data in human experiments are analyzed. In-depth characterization using pharmacokinetics is useful for obtaining information for understanding the molecular basis of pharmacological activity, for correct doses and treatment schemes selection, and for more effective drug application. Thus, an increase in pharmacokinetic research on marine-derived compounds is expected in the near future.     

Novel food and non-food uses for sorghum and millets

Sorghum and millets have considerable potential in foods and beverages. As they are gluten-free they are suitable for coeliacs. Sorghum is also a potentially important source of nutraceuticals such antioxidant phenolics and cholesterol-lowering waxes. Cakes, cookies, pasta, a parboiled rice-like product and snack foods have been successfully produced from sorghum and, in some cases, millets. Wheat-free sorghum or millet bread remains the main challenge. Additives such as native and pre-gelatinised starches, hydrocolloids, fat, egg and rye pentosans improve bread quality. However, specific volumes are lower than those for wheat bread or gluten-free breads based on pure starches, and in many cases, breads tend to stale faster. Lager and stout beers with sorghum are brewed commercially. Sorghum's high-starch gelatinisation temperature and low beta-amylase activity remain problems with regard to complete substitution of barley malt with sorghum malt . The role of the sorghum endosperm matrix protein and cell wall components in limiting extract is a research focus. Brewing with millets is still at an experimental stage. Sorghum could be important for bioethanol and other bio-industrial products. Bioethanol research has focused on improving the economics of the process through cultivar selection, method development for low-quality grain and pre-processing to recover valuable by-products. Potential by-products such as the kafirin prolamin proteins and the pericarp wax have potential as bioplastic films and coatings for foods, primarily due to their hydrophobicity.