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绿茶饮料贮藏期间主要生化成分和典型香气成分的变化及相关性研究 总被引：2，自引：1，他引：1
对绿茶饮料在贮藏期间主要生化成分、芳香成分的变化及二者的相关性进行了研究。结果表明,绿茶饮料在贮藏期间总酚含量呈下降趋势,贮藏12月后总酚减少26.6%;主要儿茶素EGCG含量下降明显,贮藏6个月和12个月后,饮料中EGCG的损失率分别达57.2%和91.9%。茶饮料在储藏过程中有H2O2产生,且H2O2的含量呈动态变化;游离氨基酸在贮藏一个月后损失率约为68%,当贮藏4个月后,其总量又有所增加;绿茶饮料贮藏过程中香气成分的种类和含量均明显增加,饮料中典型的呈香物质,如芳樟醇、芳樟醇氧化物、香叶醇、β-紫罗兰酮、己醛、橙花醇、苯甲醛的含量均随贮藏时间的延长而增加;利用SAS软件进行相关性分析表明,生化成分的变化与典型香气成分变化呈正相关;其中,儿茶素氧化和H2O2含量变化导致芳樟醇、芳樟醇氧化物、香叶醇、β-紫罗兰酮、苯甲醛和橙花醇含量增加;氨基酸和H2O2的变化导致己醛含量增加。进一步采用多元逐步回归分析表明,儿茶素氧化是导致饮料香气成分发生变化的主导因素。 相似文献
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湖北红茶特征性香气成分分析 总被引：1，自引：0，他引：1
本研究采用感官审评法和顶空固相微萃取法,并结合关键香气成分的气味活度值(Odour activity value,OAV)和主成分分析法,对32个典型湖北红茶样品的挥发性成分进行分析鉴定。结果表明,湖北红茶的香气以甜香为主,部分样品有花果香、糖香、高火香;分析鉴定出93种香气成分,醇类和醛类是主要的化合物,相对含量较高的共性成分有芳樟醇、香叶醇、水杨酸甲酯和己醛等;10个OAV相对较高的组分,主要是芳樟醇、β-大马烯酮、β-紫罗酮、癸醛、香叶醇、顺-4-庚烯醛、反-2-壬烯醛、己醛、1-辛烯-3-醇和反,反-2,4-壬二烯醛,对湖北红茶香气特征贡献较大;从19个共性成分中提取了7个主成分,累积贡献率达到86.477%;芳樟醇、香叶醇、水杨酸甲酯、1-辛烯-3-醇、β-大马烯酮、β-紫罗酮、反-香叶基丙酮、苯乙醛、癸醛、己醛、反-橙花叔醇、2-乙基呋喃和柠檬烯等香气成分共同形成了湖北红茶甜香、糖香等风味特征。 相似文献
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采用顶空固相微萃取(HS-SPME)联合GC-MS法测定了水仙白、建阳贡眉的香气成分,并对其香气化学成分及含量进行比较。结果表明在不同白茶中共检测出香气成分40种进行分析,其中醇类11种、醛类8种、碳氢化合物7种、酯类6种、杂氧化合物1种、酮类4种、含氮化合物2种、酸类1种,水仙白与建阳贡眉共检测出的主要香气成分有24种。水仙白的主要香气成分有芳樟醇、甲基庚烯酮、叶醇、月桂烯、壬醛、苯乙醛、水杨酸甲酯等;建阳贡眉的主要香气成分有己醛、青叶醛、香叶醇、月桂烯、水杨酸甲酯、苯甲醛、苯乙醇等。 相似文献
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祁门红茶的香气特征 总被引：26，自引：7，他引：26
通过对祁红当家品种——槠叶群体种及其适制绿茶的亲缘种——安徽7号(对照)在加工红茶的过程中香气形成的动态分析和比较研究表明,在祁红检出的110多种香气成分中,己醛,1-戊烯-3-醇、反-2-己烯醛、顺-3-己烯醇、芳樟醇氧化物Ⅱ、芳樟醇、香叶醇、橙花叔醇等含量较高。在相同的祁红加工过程中,槠叶群体的香气物质形成总量高于对照,且形成高峰超前,其中香叶醇含量在揉捻阶段剧增;与安徽7号相比,香叶醇含量高出30倍以上,而其他香气成分含量则无明显差异。实验还发现,两品种茶叶在加工过程中,儿茶素的减少与茶叶香气总量及其中的萜烯醇类的增长均具有很好的对应关系,槠叶群体中有关香气配糖体的含量高于安徽7号,文中对此作了讨论。 相似文献
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英德红碎茶香气化学组成的研究 总被引：1，自引：0，他引：1
用GC／MS技术，分析了美德红碎茶(云南大叶为原料)香气的化学组成。结果表明，在所鉴定的37个组分中，醇类化合物合量约占香气发挥油总量的64％，其中萜烯醇类含量为50％。以芳樟醇及其氧化物、香叶醇、(反)-2-已烯醛、苯己醛、橙花叔醇、(顺)-3-已烯醇、β-紫萝酮 (顺)-茉莉酮、水杨酸甲脂等香气化合物组分为主体特征。 相似文献
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信阳毛尖茶芳香成分研究进展 总被引：1，自引：0，他引：1
本文叙述了茶叶香气成分分类、形成机理和绿茶香气成分提取、分析方法,引出信阳毛尖茶香气成分形成的诸多因素,分析出信阳毛尖特征香气成分主要有:苯乙烯、α-雪松醇、α-蒎烯、δ-杜松烯、甲苯、戊醇、苯甲醇、苯乙醇、2-乙基己醇、橙花叔醇、反香叶醇、芳樟醇、橙花醇、反式植醇、庚醛、壬醛、苯甲醛、β-环柠檬醛、6-甲基-5-庚烯-2-酮、紫罗酮、5,6-环氧基紫罗酮、Z-茉莉酮、2,2,6-三甲基环己酮、棕榈酸、2-乙基呋喃、己酸顺式-3-己烯酯、2-乙基吡咯等。 相似文献
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采用固相萃取法结合气相色谱-质谱（GC-MS）技术对茶树新品系‘椀香茗’工夫红茶香气成分进行检测分析，旨在探究该品系红茶的香气特征。结果表明：茶树新品系‘椀香茗’夏季一芽一叶工夫红茶共检测出39种主要香气成分，主要为醇类、醛类、酯类、酮类、杂氧化合物与烯烃等，其中醇类、醛类、酯类是该红茶香气的主要成分，占香气总量的84.28%。该品系红茶香气类型与中阿杂交的大吉岭及云南红茶属于同一类，香气成分相对含量较高的水杨酸甲酯、香叶醇、苯乙醇、β-芳樟醇、芳樟醇氧化物、2-正戊基呋喃、β-环柠檬醛、β-紫罗酮及苯甲醛等和相对含量较少的壬醛、柠檬烯、β-月桂烯、顺-茉莉酮、橙花醇、α-雪松醇、苯乙醛、α-萜品醇等都呈花果香，是花果香型红茶的主要成分，表明茶树新品系‘椀香茗’夏茶鲜叶制工夫红茶花果香浓郁、香气好，具有开发高香优质红茶的潜质。 相似文献
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遮荫和施肥对夏茶醇系香气物质的影响 总被引：6，自引：0，他引：6
茶叶香气与其品质有着十分密切的关系。而在茶叶香气成分中,醇系香气物质占据了重要地位。试验表明,岭头单丛茶鲜叶中含量较多的香气物质有芳樟醇及其氧化物,以及香叶醇和萜品醇;在肉桂茶香气中,橙花叔醇、芳樟醇及其氧化物、香叶醇这３种醇类香气物质的含量共占香气成分总量的５０％以上;香叶醇、萜烯醇类物质、芳环醇（如苯乙醇）、芳樟醇及其氧化物、ａ－萜品醇等都是组成和影响祁门红茶香气的主要芳香物质;香叶醇、苯甲醇、苯乙醇等是韩国传统绿苯Ｊａｃｋｓｏｌ茶的主要香气成分。由此可见,醇系香气物质对茶叶品质有着重要的影… 相似文献
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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
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《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
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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
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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
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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
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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
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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
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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