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近年来,以清饮为主的国内功夫红茶消费形成新的茶叶消费热点,形成了对“香高、味醇、色亮“清醇型高级工夫红茶消费热潮。本实验试着将乌龙茶的晒青工艺添加到红茶制作中,以求改善红茶的品质。研究用福云六号和金黄两个品种鲜叶进行日光萎凋(设不晒、轻晒、重晒处理)、室内萎凋、机械揉捻、发酵、烘干的工艺组合制得红茶样。通过感官审评和生化成分对茶样进行比较分析,探讨了“晒青“工序对红茶品质的影响。结果表明:(1)晒青处理的红茶与对照香型没有差异,但经过晒青处理的红茶甜香更浓郁,香气也更持久:(2)晒青处理的红茶水浸出含量增加,多酚类含量增加,茶黄素含量减少,茶红素含量增加,氨基酸的含量也增加了,滋味较醇和:(3)晒青处理可以显著提高红茶的香气,对红茶滋味的醇厚度也有所提高,因此在红茶加工中引入晒青工艺对开发清饮型高香红茶具有很好的现实意义。 相似文献
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不同产地红茶主要品质成分分析 总被引:3,自引:0,他引:3
通过收集国内外不同地区具有代表性的红茶茶样,对其进行感官审评与理化成分分析。结果表明,感官方面,国外红茶样整体水平优于国内红茶样品。内含品质成分方面,云南大叶种红茶水浸出物含量较高;氨基酸含量则均在3%~5%之间,差异并不明显;国外红茶样茶多酚平均含量高出国内红茶样2.66%;咖啡碱含量在2.35%~5.45%之间,其中产于斯里兰卡的两个红茶样高于其他地区红茶;国外红茶样茶黄素含量整体较高,茶红素以肯尼亚红碎茶含量最高,国内红茶样则是茶褐素含量普遍较高。 相似文献
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热风提香温度对工夫红茶品质的影响 总被引:1,自引:0,他引:1
《广东茶业》2015,(4)
利用6CZG-60型热风整形平台进行工夫红茶的提香试验,分析不同提香温度对工夫红茶感官品质及主要生化成分的影响。结果表明,随着提香温度的升高,各处理茶样的感官品质先增后降,130℃提香处理的红茶感官品质最好,115℃提香次之;氨基酸和可溶性糖含量呈现不同程度的减少趋势,而茶多酚含量变化不显著。适当的提香能一定程度的提高红茶滋味及香气品质,提香温度不应高于145℃,最适在115℃-130℃之间,所得红茶香气高甜,滋味鲜醇,综合品质突出。 相似文献
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茶叶实物标准样对于客观准确地鉴别茶叶品质是不可或缺的,简述湖南红茶实物标准样制备流程,并分析其感官品质特点及生化成分。结果表明,湖南红茶特级标准样氨基酸含量最高,滋味甜醇甘鲜,鉴定出的110种挥发性香气物质中萜类物质含量显著高于其他茶样,香气表现为嫩甜香浓郁持久;湖南红茶一级标准样水浸出物和儿茶素含量最高,滋味醇厚甘爽,鉴定出114种挥发性香气物质,各类挥发性成分含量居中,呈现出纯正甜香;湖南红茶二级标准样滋味成分含量相对较低,滋味甜醇尚浓,鉴定出109种挥发性香气物质,来源于脂肪酸和类胡萝卜素的挥发性物质含量显著高于其他茶样,表现为甜香带花香。本研究可为湖南红茶加工生产提供参考。 相似文献
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Sena L.P. VanderJagt D.J. Rivera C. Tsin A.T.C. Muhamadu I. Mahamadou O. Millson M. Pastuszyn A. Glew R.H. 《Plant foods for human nutrition (Dordrecht, Netherlands)》1998,52(1):17-30
In the western Sahel, indigenous plants become important staples when cereal harvests are inadequate to support populations inhabiting that region of Africa. The purpose of this study was to assess the nutrient content of several of these edible wild plants. The leaves of the following seven plant foods were analyzed: Ziziphus mauritiana, Cerathotheca sesamoides, Moringa oleifera, Leptadenia hastata, Hibiscus sabdarifa, Amaranthus viridi, and Adansonia digitata. The fatty acid, vitamin E, carotenoid, selected mineral and amino acid contents of these plant foods were determined. These same analyses were performed on the fruit of the Adansonia digitata. In quantitative and qualitative terms, Amaranthus viridis was found to be an excellent source of protein. Its amino acid composition compared favorably to that of a World Health Organization (WHO) protein standard. It also contained considerable amounts of the two fatty acids that are essential in humans (linoleic and -linolenic) and a number of minerals including iron, magnesium, calcium and zinc. The leaves of Hibiscus sabdarifa contained an appreciable quantity of protein the composition of which was comparable to the WHO standard. The mineral content of the leaves of this plant was also exceptionally high; noteworthy was its high zinc content. H. sabdarifa also contained significant quantities of the two essential fatty acids. Ziziphus mauritiana was an excellent source of the essential fatty acid linoleic acid and several of the metals including iron, calcium, magnesium and zinc. Its content of other essential nutrients, however, was rather low. In general, Adansonia digitata leaves were nutritionally superior to the fruit of the tree; however, the fruit did contain useful quantities of potassium, phosphorus, zinc and -linolenic acid. The Leptadenia hastata leaves were an especially good source of lutein and -carotene. These data should be useful to the people who inhabit the western Sahel in helping them devise healthy diets during times when cereal staples are in short supply. 相似文献
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通过电解质外渗法和匍匐茎恢复试验对‘阳江’狗牙根及其12个通过形态鉴定选出的坪用价值高且花序密度低的诱变后代进行抗寒性鉴定。电解质外渗法结果表明:诱变后代间的抗寒性具有较大差异,其叶片半致死温度(LT50)的变异范围为-7.6~-0.2℃(最低值与最大值相差7.4℃);参试材料抗寒性由强到弱依次为M18>M4>M26>M28> M22>阳江>M29>M31>M10>M37>M16>M1>M25,其中,有5个诱变后代抗寒性优于亲本,分别是M18、M4、M26、M28、M22。匍匐茎恢复实验结果表明:诱变后代M1、M22、M26、M31、M25在0℃和-5℃低温胁迫后的恢复生长率都高于亲本,恢复能力均优于亲本;M10、M37、M28在-5℃低温胁迫下,恢复生长能力低于亲本,抗寒性相对较弱,M16和M4在0℃和-5℃低温胁迫下,恢复生长率都低于亲本,抗寒性明显弱于亲本。综合2种方法鉴定结果显示:诱变后代M1、M25的恢复能力较强;M4、M28的叶片抗寒性较好,青绿期较长;M22、M18、M26的叶片抗寒性和匍匐茎恢复能力均较强;M29,M31的叶片抗寒性和匍匐茎恢复能力与亲本相似;M10、M16、M37的叶片抗寒性和匍匐茎恢复能力均较弱,整体抗寒性较弱。 相似文献
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橡胶树丛枝病病原的抗血清制备与应用 总被引:5,自引:1,他引:4
以感染橡胶树丛枝病病原的长春花为材料,制备得到橡胶丛枝病病原菌抽提液,以抽提液为抗原免疫家兔,制备抗血清,经微量沉淀测定,抗血清效价为1:2048。应用橡胶丛枝病抗血清检测橡胶褐皮病,无症苗木检出率达30%-37%,可疑的褐皮病树检出率达85.7%。 相似文献
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R. W. Summers 《Crop Protection》1989,8(6):451-454
One hundred and fifty-six pre-roost gatherings of starlings were observed at 28 sites around a roost in west Norfolk during winter. Pre-roost gatherings occurred more frequently at individual farmyards compared with individual fields, but 82% of the sites where gatherings occurred were on fields. The size of gatherings was greater, the closer to the roost. Birds in pre-roost gatherings on fields of autumn-sown winter wheat spent most of the time feeding and had a diet composed almost exclusively of wheat seeds. Birds in gatherings on grass fields also fed intensively whereas only 31% of birds at farmyards were feeding. The implications that these results have with regard to potential damage to fields of winter wheat and around farmyards are discussed. 相似文献
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Insect pest management is facing the economic and ecological challenge worldwide due to the human and environmental hazards caused by majority of the synthetic pesticide chemicals. Identification of novel effective insecticidal compounds is essential to combat increasing resistance rates. Botanicals containing active insecticidal phytochemicals appear to be promising to address some of these problems. Therefore, there is a continuous need to explore new active molecules with different mechanisms of action. Secondary metabolites present in plants apparently function as defense (toxic), which inhibits reproduction and other processes. The phytochemical biomolecules could be used for maximizing the effectiveness and specificity in future insecticide design with specific or multiple target sites, while ensuring the economic and ecological sustainability. In this article, the current state of knowledge on phytochemical sources and insecticidal activity, their mechanism of action in insects, resistance, and promising advances made in phytochemical research are reviewed. 相似文献
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为深入研究昆虫病原真菌蝉拟青霉疏水蛋白PChyd基因的功能,根据蝉拟青霉基因组信息克隆疏水蛋白PChyd基因,对该基因序列进行生物信息学分析,使用qRT-PCR技术对其在不同培养条件或阶段下的表达模式进行分析,并通过酶切酶连的方法构建了该基因的敲除载体。结果表明:PChyd基因的开放阅读框序列全长303 bp,编码100 aa,包含22 aa的信号肽序列和70 aa疏水蛋白功能区域。系统发育分析显示该基因与粗糙虫草菌亲缘关系最近。qRT-PCR结果显示PChyd基因在PDA培养的菌丝体、诱导的附着胞、诱导的芽生孢子中表达量显著高于另外2个样品,其中芽生孢子表达量最高,暗示该基因在蝉拟青霉侵染初期和在昆虫血腔中定殖阶段可能具有重要作用。凝胶电泳结果表明,成功构建了该基因的敲除载体,扩增出含有上臂、HPH、下臂的3356 bp左右的片段。本研究为进一步探究蝉拟青霉疏水蛋白PChyd基因的致病机理、生防工程菌的改造奠定了基础。 相似文献
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为了寻找一种高效的荔枝果实瞬时基因表达方法,本研究以荔枝品种‘新球蜜荔’(Litchi chinensis Sonn. var. ‘Xinqiumili’)为试材,利用农杆菌注射法对荔枝果实组织进行转化,研究了果实发育时期、菌株种类、注射部位、取样时间、菌液浓度等对转化效率的影响。结果表明:选择果肉已完全包裹种子的Ⅱb期果实进行连体注射,在果柄、果皮、种子、果肉分别注入OD600值为2.4的农杆菌菌株GV3101,4 d后取样进行检测,4个组织的GUS染色率较高。本研究成功建立了适用于荔枝果实的基因瞬时表达系统,为今后快速鉴定荔枝果实相关基因功能提供了基础。 相似文献
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2020年10月17日,《中华人民共和国生物安全法》(以下简称《生物安全法》)通过全国人大常委会的审
议,自2021年4月15日起施行。生物技术的研究与应用安全是《生物安全法》涉及的主要内容之一,基因编辑作为
近几年生物技术领域的研究热点,其安全性评价和监管备受关注。本文概述了基因编辑技术的应用现状,比较了
不同国家对基因编辑技术的监管制度,探讨了我国《生物安全法》的出台对基因编辑技术安全评价与监管的重要意
义,最后就如何在基因编辑生物安全领域更好地推进和落实《生物安全法》提出了建议。 相似文献