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1.
对长沙市场10种热销茶叶及其泡饮后的茶渣进行有机氯(BHC和DDT)农药残留测定分析，检测结果表明只有2种抽查样品有机氯残留略微超标。DDT含量均高于BHC。从泡饮后茶渣的检测结果可知，茶叶中的有机氯残留几乎不溶于茶汤中。 相似文献
2.
山羊草属不同细胞质对小麦籽粒戊聚糖含量的影响 总被引：2，自引：0，他引：2
为了利用小麦近缘野生种属的细胞质资源改良小麦品质,以山羊草属(Aegilops)不同种异源细胞质的5种异质小麦品种Chris为材料,与生产上广泛推广种植的4个常规小麦品种进行正反杂交,研究了异源细胞质对其F1籽粒戊聚糖含量的影响.结果表明:(1)在以5种异源细胞质材料为母本的杂交组合中, 仅有50%的组合其总戊聚糖含量高于反交对照,粗山羊草和偏凸山羊草细胞质对总戊聚糖含量具有普遍的正效应;粘果山羊草细胞质对总戊聚糖含量表现出轻微的正效应;柱穗山羊草和二角山羊草细胞质则表现出明显的负效应;(2)在以5种异源细胞质材料为母本的杂交组合中, 80%的组合其水溶性戊聚糖含量高于反交对照, 除二角山羊草细胞质对水溶性戊聚糖含量表现出负效应外,其他4种细胞质对水溶性戊聚糖含量都有一定的正效应,但5种细胞质之间差异均不显著;(3)尽管5种异源细胞质对水溶性戊聚糖含量效应差异不显著,但是柱穗山羊草、偏凸山羊草、粘果山羊草和粗山羊草细胞质对水溶性戊聚糖含量有一定的正效应.因此,如果选择合适的核质组合同样可以达到改良戊聚糖含量的目的. 相似文献
3.
利用火焰原子吸收光谱法对不同季节采摘的蒙山茶鲜叶及其浸出液中矿质元素Ca、Mg、Fe、Mn、Cu、Zn的含量进行测定,计算出茶叶浸出液中各元素溶出率。应用SPSS-18.0分析软件对鲜叶中各元素含量进行相关性分析,并讨论了各元素在茶叶中季节性变化规率。结果表明：茶叶中含有丰富的矿质元素,各元素含量从高到低依次是Ca>Mg>Mn>Fe>Zn>Cu;各矿质元素含量的季节动态具有明显的规律性;茶叶中Ca和Mg元素,Fe和Mn元素含量呈显著正相关趋势,Ca和Zn元素间存在显著负相关。相同条件下,不同元素的溶出率与该元素在茶叶中存在形态相关,而与其在茶叶中含量及采摘季节无显著关系。 相似文献
4.
为了解黑小麦中硒含量及其赋存形态,对运黑14207的硒含量及其在蛋白质、多糖和核糖中的含量及各组分抗氧化性进行了测定。结果表明,运黑14207硒含量为0.185 mg·kg-1,有机硒含量占总硒含量58.56%;有机硒主要以蛋白结合态形式存在,蛋白结合态硒含量占总有机硒含量的78.84%。八种提取组分中,水溶性多糖得率最高,为11.08%;水溶性蛋白硒含量最高,为1.53 mg·kg-1。运黑14207粉中,碱溶性蛋白结合硒含量占比最高,为23.38%。在抗氧化特性方面,水溶性多糖及水溶性蛋白较其他组分对ABTS、DPPH、Fe3+均具有较高的清除力,但均低于对照Vc。研究表明,运黑14207属于富硒谷物,为后续富硒产品开发提供了理论依据。 相似文献
5.
茶叶中稀土元素的组成及存在状态 总被引：13，自引：0，他引：13
用ＩＣＰ ＭＳ分析了安徽省郎溪茶场的茶叶及茶园土壤中的稀土元素含量、组成及存在状态。结果表明：茶叶中含有其栽培土壤中所有的１５种稀土元素，其中以Ｌａ、Ｃｅ、Ｎｄ、Ｐｒ和Ｙ为主，这５种元素含量之和占稀土总量的９２％。茶叶中和土壤中的稀土元素在组成和分布模式上基本相同，只是茶叶对Ｌａ吸收相对较多，而对Ｃｅ、Ｙｂ吸收相对较少而已。茶叶中的稀土元素四分之三以上是不溶于热水而残存在茶渣中，其中又有１６％是与α 纤维素结合在一起的，因此，人们喝茶时摄入的稀土元素不足茶叶中稀土含量的四分之一（约０４８ｍｇ／ｋｇ，远低于≤２０ｍｇ／ｋｇ的国家允许标准）。茶叶中存在有稀土多糖复合物，茶汤中约有８％的稀土是以这种状态存在的。在稀土多糖中以Ｌａ、Ｃｅ、Ｎｄ为主，其含量约占８０％以上。 相似文献
6.
近年来,茶叶中的有效成分的研究与开发利用越来越受到人们的关注,尤其是茶多酚、咖啡碱和茶叶多糖,这不仅与它们的药用价值有关,还和粗老茶叶存在的广泛性及其销售的劣势密切相关。众所周知,不论是何茶类,夏茶、暑茶或中低档茶的品质都较差。因此,对于这部分茶的消费必须另辟新径。在我国和日本民间,有用粗老茶治疗糖尿病的经验,并且茶叶愈粗老糖尿病治疗的效果愈好。日本的清水岑夫[1]研究发现,茶叶中具有降血糖效果的成分是茶多糖。茶叶中的多糖含量是随茶叶原料的粗老度而增加的[2],也就是说,茶叶越粗老,多糖的含量越高;茶叶多糖不仅具有… 相似文献
7.
茶叶多糖铁的合成及其铁含量的测定 总被引：8，自引：0，他引：8
用热水浸泡法从粗老茶叶中提取茶叶多糖,在碱性条件下,茶叶多糖水溶液与三氯化铁反应合成茶叶多糖铁配合物(TPC),并用邻菲罗啉分光光度法和原子吸收光谱法测定TPC中铁(Ⅲ)的含量。实验结果表明:TPC是深棕红色无定型粉末,易溶于水,在pH值3~12范围内不沉淀,不水解。TPC中铁(Ⅲ)的含量:邻菲罗啉分光光度法测定结果为20.71%,原子吸收光谱法测定结果为20.13%。 相似文献
8.
通过测定活性成分、矿质元素、微量元素、氨基酸等营养成分含量,研究了制作工艺处理对金花茶老叶营养成分的影响。结果表明:制作工艺处理金花茶叶活性成分茶多糖含量升高60.00%,皂苷、咖啡碱含量分别下降27.05%和71.83%,黄酮、茶多酚和维生素E(Ve)含量分别下降39.40%、19.64%和20.57%;矿质元素中镁(Mg)、磷(P)、钾(K)含量分别升高5.56%、8.85%和9.19%,钙(Ca)、钠(Na)含量下降103.46%和4.10%;微量元素中铜(Cu)、锰(Mn)、锌(Zn)、硒(Se)含量分别升高7.75%、4.33%、3.14%和28.05%,铁(Fe)含量下降9.85%;氨基酸总量增加10.00%。 相似文献
9.
豆渣中水溶性大豆多糖的提取工艺研究 总被引：1，自引：0，他引：1
大豆多糖是大豆中的有效活性成分之一,具有抗氧化性、食品稳定性等作用.以市售豆渣为材料,采用不同的提取温度、液固比和提取时间进行单因素试验,然后在此基础上采用三因素三水平的正交试验对水溶性大豆多糖的提取条件进行优化.结果表明:提取温度对水溶性大豆多糖提取率的影响最大,其次是液固比,再次是提取时间.水溶性大豆多糖提取的最优工艺参数是:提取温度为90℃、液固比为5:1、提取时间为3 h.经苯酚-硫酸法测定,水溶性大豆多糖含量为7.47%(以葡萄糖计). 相似文献
10.
无机元素与茶树的生长发育、物质代谢乃至茶叶的产量和品质关系密切,近年来,对茶叶中无机元素含量的研究报道日益增多。竹尾忠一(1980)测定了日本和国外一些茶叶中无机元素的含量,指出各元素之间及其与茶叶滋味、品质评分之间存在着明显的相关性,戴寰 相似文献
11.
12.
《Journal of Crop Improvement》2013,27(2):81-114
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. 相似文献
13.
Lakshman Lal 《Potato Research》1987,30(2):329-334
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. 相似文献
14.
15.
Joseph E. Laferriere Charles W. Weber Edwin A. Kohlhepp 《Plant foods for human nutrition (Dordrecht, Netherlands)》1991,41(3):277-282
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. 相似文献
16.
Novel food and non-food uses for sorghum and millets 总被引：4，自引：3，他引：4
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. 相似文献
17.
M. I. Siri P. Villanueva M. J. Pianzzola L. Franco Fraguas G. Galván M. Acosta F. Ferreira 《Potato Research》2004,47(3-4):127-138
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. 相似文献
18.
Alejandro Carlos Tozzini María Fernanda Ceriani María Verónica Saladrigas H. Esteban Hopp 《Potato Research》1991,34(3):317-324
Summary Clones derived from thirty-one different accessions (nineteen of Argentine origin) belonging to eightSolanum species were screened for resistance to infection by potato virus X strain cp (PVX cp) by mechanical inoculation of plantlets
that had been micropropagated in vitro. Estimates of PVX multiplication obtained by enzyme linked immunosorbent assay and
slot blot nucleic acid hybridization allowed the identification of resistant clones derived from five accessions belonging
toS. commersonii S. oplocense, S. sparsipilum andS. tuberosum andigena. Resistant genotypes supported PVX concentrations 5 to 15 times smaller than did the susceptible control cultivar Spunta.
Graft inoculation test confirmed the presence of extreme resistance similar to that conferred by the ‘immunity’ gene X1 (also called RXact). 相似文献
19.
Rita Favas Janaína Morone Rosrio Martins Vitor Vasconcelos Graciliana Lopes 《Marine drugs》2022,20(3)
The loss of density and elasticity, the appearance of wrinkles and hyperpigmentation are among the first noticeable signs of skin aging. Beyond UV radiation and oxidative stress, matrix metalloproteinases (MMPs) assume a preponderant role in the process, since their deregulation results in the degradation of most extracellular matrix components. In this survey, four cyanobacteria strains were explored for their capacity to produce secondary metabolites with biotechnological potential for use in anti-aging formulations. Leptolyngbya boryana LEGE 15486 and Cephalothrix lacustris LEGE 15493 from freshwater ecosystems, and Leptolyngbya cf. ectocarpi LEGE 11479 and Nodosilinea nodulosa LEGE 06104 from marine habitats were sequentially extracted with acetone and water, and extracts were analyzed for their toxicity in cell lines with key roles in the skin context (HaCAT, 3T3L1, and hCMEC). The non-toxic extracts were chemically characterized in terms of proteins, carotenoids, phenols, and chlorophyll a, and their anti-aging potential was explored through their ability to scavenge the physiological free radical superoxide anion radical (O2•−), to reduce the activity of the MMPs elastase and hyaluronidase, to inhibit tyrosinase and thus avoid melanin production, and to block UV-B radiation (sun protection factor, SPF). Leptolyngbya species stood out for anti-aging purposes: L. boryana LEGE 15486 presented a remarkable SPF of 19 (at 200 µg/mL), being among the best species regarding O2•− scavenging, (IC50 = 99.50 µg/mL) and also being able to inhibit tyrosinase (IC25 = 784 µg/mL), proving to be promising against UV-induced skin-aging; L. ectocarpi LEGE 11479 was more efficient in inhibiting MMPs (hyaluronidase, IC50 = 863 µg/mL; elastase, IC50 = 391 µg/mL), thus being the choice to retard dermal density loss. Principal component analysis (PCA) of the data allowed the grouping of extracts into three groups, according to their chemical composition; the correlation of carotenoids and chlorophyll a with MMPs activity (p < 0.01), O2•− scavenging with phenolic compounds (p < 0.01), and phycocyanin and allophycocyanin with SPF, pointing to these compounds in particular as responsible for UV-B blockage. This original survey explores, for the first time, the biotechnological potential of these cyanobacteria strains in the field of skin aging, demonstrating the promising, innovative, and multifactorial nature of these microorganisms. 相似文献
20.
Alejandro M. S. Mayer Abimael D. Rodríguez Orazio Taglialatela-Scafati Nobuhiro Fusetani 《Marine drugs》2013,11(7):2510-2573
The peer-reviewed marine pharmacology literature from 2009 to 2011 is presented in this review, following the format used in the 1998–2008 reviews of this series. The pharmacology of structurally-characterized compounds isolated from marine animals, algae, fungi and bacteria is discussed in a comprehensive manner. Antibacterial, antifungal, antiprotozoal, antituberculosis, and antiviral pharmacological activities were reported for 102 marine natural products. Additionally, 60 marine compounds were observed to affect the immune and nervous system as well as possess antidiabetic and anti-inflammatory effects. Finally, 68 marine metabolites were shown to interact with a variety of receptors and molecular targets, and thus will probably contribute to multiple pharmacological classes upon further mechanism of action studies. Marine pharmacology during 2009–2011 remained a global enterprise, with researchers from 35 countries, and the United States, contributing to the preclinical pharmacology of 262 marine compounds which are part of the preclinical pharmaceutical pipeline. Continued pharmacological research with marine natural products will contribute to enhance the marine pharmaceutical clinical pipeline, which in 2013 consisted of 17 marine natural products, analogs or derivatives targeting a limited number of disease categories. 相似文献