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茶树育种品质早期化学鉴定——Ⅱ.鲜叶的主要生化组分与绿茶品质的关系 总被引:3,自引:0,他引:3
用直线和曲线模型,模拟分析了60个品种(系)鲜叶中的主要生化组分与绿茶感官。品质的关系,结果表明,水浸出物(We)、儿茶素(TC)和咖啡碱(Cf)与绿茶品质(GQ)的关系可用二次曲线模型(GQ=32.48+3.043We-0.0429We~2,GQ=84.5329+0.0463TC-0.0003 TC~2,GQ=48.57+18.3629Cf-2.2402 Cf~2)来模拟,茶多酚与绿茶品质之间也呈二次曲线关系,但以其对水浸出物的相对含量(Ph/We)来分析比绝对含量更适宜[GQ=80.23+0.3058 Ph/We-0.0037(Ph/We)~2],氨基酸(A)、酚氨比(P/A)和还原糖(S)与绿茶品质的关系宜用直线模型(GQ=79.94+2.3652A,GQ=87.88-0.2107P/A,GQ=87.5816-3.142S)来描述。 相似文献
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香气粗老是影响夏秋绿茶品质的重要因素。为提高夏秋绿茶品质,以福鼎大白茶为研究对象,以自然摊青为对照,采用红光、黄光、蓝光和紫光对离体鲜叶进行辐照,通过顶空固相微萃取-气质联用技术(HS-SPME-GC-MS)检测摊青叶挥发性成分,使用层次聚类(HCA)、主成分分析(PCA)和偏最小二乘判别分析(PLS-DA)等分析方法,探究促进茶叶花果香形成的最适光质及关键物质。结果显示,不同光质对挥发性物质种类、含量具有显著影响;从5个样品中共鉴定出36种挥发性物质,其中醇类与萜烯类物质种类最多,酯类和醇类化合物平均含量较高;红光是促进茶叶花香物质形成的最佳光质,3-蒈烯、β-月桂烯、苯乙醇等物质是茶叶花香形成的关键物质;4种光质均能显著降低茶多酚含量,显著增加游离氨基酸和咖啡碱含量,降低酚氨比。感官审评结果显示,与对照组相比,4种光质辐照后的茶叶香气清爽、滋味鲜爽,其中红光辐照的茶叶感官评分最高。研究表明,红光辐照夏秋茶离体鲜叶能够增加茶叶香气物质的种类和含量,显著提高花果香形成的关键物质,增加茶汤鲜爽味。 相似文献
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绿茶一直是我国的主要茶类。传统大宗绿茶加工一般都包括杀青、揉捻、干燥等工序。为适应高档绿茶市场需求日益增加的现状,安徽省农业科学院茶叶研究所示范茶场近年来一直致力于改进绿茶加工工艺以提高其质量。经多次试验比对,确定以适度摊放和揉捻为主要工序制作的绿茶不但滋味醇爽,经久耐泡,且香气纯正浓郁又带有花香。产品自投放市场以来一直深受好评。该茶加工工序为鲜叶摊放-杀青-揉捻-理条-初烘-摊凉-复烘。 相似文献
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茶鲜叶匀浆悬浮发酵工艺监测参数 总被引:3,自引:0,他引:3
采用电极法对茶鲜叶匀浆悬浮发酵过程中的氧化还原电位(ORP)、溶解氧(DO)浓度工艺参数进行了在线检测。结果表明,发酵体系中多酚类物质消耗与ORP的变化呈显著负相关。随着多酚类物质氧化消耗及氧化产物的形成,ORP呈逐步增高,其变化曲线呈“S”型,符合Logistic方程,方程拐点可间接反映多酚类物质的保留量;DO浓度影响发酵速率和红茶品质,其变化趋势也符合Logistic方程描述的“S”型曲线,而方程拐点略早于茶黄素(TFs)峰值出现时间,故可用DO浓度变化指示TFs变化过程。发酵体系总色度(TC)变化与茶红素(TRs)形成趋势较吻合,凡影响TRs形成的因素均影响TC。 相似文献
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茶树花含有较多的营养成分和丰富的活性物质,对人体具有解毒、降脂、降糖、抗癌、滋补、养颜等功效。本研究以金萱品种为原料,采用不同杀青方式和干燥方式加工的成茶,对其进行感官审评。实验结果表明,蒸汽杀青和远红外干燥更适宜茶树花的加工。 相似文献
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制茶工艺与名优绿茶香气形成的相关性研究进展 总被引:4,自引:0,他引:4
香气是名优绿茶的重要品质因子之一,良好的香气品质主要在茶叶加工中形成。本文分别叙述了茶叶摊放、杀青(青锅)、揉捻做形、干燥(辉锅)及干燥后增香对香气物质转化和茶叶香气品质的影响;并对茶叶香气形成机理进行了阐述,重点介绍了糖苷酶的相关性研究。 相似文献
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The present paper reports the impact of thermal treatment on the characteristics of core-sheath type hybrid technical yarns.
The core-sheath type hybrid yarns are prepared using DREF-III technology. Polyester and glass multifilaments are used as core
components whereas the cotton and polyester staple fibers are the sheath components wrapped around the core filament with
different proportions to form a hybrid structure. The thermal treatment is carried out both in dry and in wet state under
relaxed condition and the thermal shrinkage, sheath-slipping resistance and tensile and bending properties of hybrid yarns
have been studied. Thermal treatment markedly increases the thermal shrinkage and sheath-slipping resistance of hybrid yarns
with polyester multifilament in core, but insignificant effect for yarns with glass multifilament in core. Breaking elongation
of hybrid yarns with polyester multifilament in core increases with treatment temperature. The hybrid yarns with glass multifilament
in core are least affected by thermal treatment. 相似文献
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1995年 ,宁夏引进小麦覆膜机 ,在它的启发下 ,开发了一种水稻种植方式——水稻机械覆膜穴播节水栽培技术 ,取得成功。这种栽培技术将成为高寒、缺水地区的一种新的种植方式。一、水稻覆膜栽培增产机理1.提高土壤温度 ,有利提早播种据试验观察 ,地膜覆盖地 0~ 5 cm土层在早春低温阶段平均比气温高 2 .1~ 3.5℃ ,其中 4月上中旬增温 3℃以上 ,为水稻提前播种创造了基本条件。 1997年 ,地膜水稻比常规旱直播提前 1个多月播种的 1.37叶龄的幼苗 ,虽遇到 - 1℃的低温 ,也未造成冻害。从另一方面也为选用优质、多抗、生育期较长的品种提供了可能… 相似文献
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This research studies the factors which influence the tensile strength of tire cords. Five yarn samples are made by changing
the spinning conditions and viscosity to get various physical properties. Different twisting methods are introduced and the
yarns are twisted under different processing conditions for each twisting process. With the experimental results, various
analyses are performed to find the important factors in retaining strength after the twisting process. SEM and optical microscopic
photographs are taken along with some measurements to assist the analysis. 相似文献
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1茶叶微波杀青、干燥机理微波杀青、干燥是微波发生器将微波辐射到杀青、干燥的物料并穿透到物料内部时,诱使物料的水等极性分子随之同步旋转,例如采用915MHz微波干燥蔬菜类物料制品,其体内极性分子每秒钟旋转9.15亿次,如此高速旋转的结果,使物料瞬时产生摩擦热,导致物料表面与内部同时升温,且内部温度高于物料表面温度,使大量的水分子从物料中逸出而被蒸发带走,这样达到杀青、干燥的目的。这种杀青、干燥方法的特点是加热时间短,内外温度一致,其热传递方向从内向外与湿传递方向也一致。茶叶杀青、干燥的要求是杀青后茶叶的含水率为58%-60%… 相似文献
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Zouhaier Romdhani Ayda Baffoun Mohamed Hamdaoui Sadok Roudesli 《Fibers and Polymers》2013,14(7):1157-1164
The main idea of this work is to study the different phenomena of spreading, evaporation, and diffusion that bound to the ink-jet printing. The coating film is studied as well as its drying morphologies and its wetting behavior. Then the drop water spreading on coated fabric is investigated. At that time spreading kinetic is characterized by the digidrop 3S which permits to measure precisely the various parameters such as contact angle, diameter, height, volume and drop profile in contact with the support during wetting phenomenon. This survey shows, on the one hand, that the coating film structure is deeply affected by drying morphologies. On the other hand, drying conditions influence different parameters of kinetic drop spreading on virgin glass and cotton material. Then the increasing of coating film thickness encourages the drop spreading. 相似文献
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K. Björling 《Potato Research》1958,1(2):1-4
Summary The numerical ratio of the deposits of sporangia of the blight fungus on the upper and lower leaf surfaces was found to vary
between 10 and 30 depending on the stage of the attack and the position of the leaves.
The ratio of infections on the upper and lower leaf surfaces had lower values than would be expected from the sporangia deposits.
At weak attack 7–8 and at heavy attack 3–4 as many infections occurred on the upper surfaces
In field trials the protection of spraying only from above was found to be on the average equally good as combined sparying
from above and from below. However, some potato varieties with an open type of growth (King Edward) were somewhat better protected
by spraying from above, while combined spraying gave somewhat better results in varieties with a closed type of growth (Bintje).
In laboratory trials with different droplet sizes on detached leaflets the smallest droplets of Bordeaux tested (M.M.D. 55μ)
gave considerably better protection against infection than larger droplets.
Articificial rain treatment of Bordeaux-sprayed leaves clearly improved an incomplete protection presumably through redistribution
of fungicidal particles to unprotected leaf areas. Similar trials with Zineb gave more irregular results; in most cases rain
deteriorated the protection.
Lecture held at the 4th International Informal Potato Conference at Lund (Sw.), August 1957. 相似文献
Zusammenfassung Das zahlenm?ssige Verh?ltnis der Depositionen von Sporangien desPhytophthorapilzes auf der Oberseite und Unterseite der Bl?tter erwies sich als schwankend zwischen 10 und 30, je nach Stadium des Befalls und Stellung der Bl?tter. Das Verh?ltnis der Infektionen auf der Oberseite und Unterseite der Bl?tter zeigte geringere Werte, als von den Sporangiendepositionen zu erwarten w?re. Bei schwachem Befall kamen 7–8 und bei starkem Befall nur 3–4 mehr Infektionen auf der Blattoberseite vor. Bei Feldversuchen ergab sich, dass der Schutz durch Spritzen „nur von oben” im allgemeinen ebenso gut war wie das kombinierte Spritzen „von oben und von unten”. Jedoch wurden einige Kartoffelsorte mit offenem Wuchs des Krautes (King Edward) etwas besser geschützt durch oberseitiges Spritzen, w?hrend das kombinierte Spritzen etwas bessere Ergebnisse zeigte bei Sorten mit geschlossenem Krautwuchs (Bintje). Bei Laboratoriumversuchen mit verschiedenen Tropfengr?ssen auf abgetrennten Bl?ttchen ergaben die kleinsten Tr?pfchen Bordeaux (Kupferkalkbrühe M.M.D. 55μ) einen bedeutend besseren Schutz gegen Infektion als die gr?sseren Tropfen. Künstlicher Regen auf den mit Bordeaux bespritzten Bl?ttchen verbesserte deutlich einen unvollst?ndigen Schutz, vermutlich durch die Neuverteilung der Partikelchen des Fungizids über die ungeschützten Blattstellen. Gleichartige Versuche mit Zineb ergaben mehr unregelm?ssige Resultate; in den meisten F?llen verschlechterte Regen den Schutz.
Resumé Il appert que la proportion numérique des dép?ts de sporanges du champignon du mildiou sur les surfaces supérieures et inférieures des feuilles varie entre 10 et 30, ceci en fonction des attaques plus ou moins sérieuses et de la position des feuilles. La proportion des infestations sur les surfaces supérieures et inférieures des feuilles a démontré des valeurs plus basses que les dép?ts de sporanges laissaient prévoir. Les surfaces supérieures des feuilles ont démontré, devant une attaque faible, 7 à 8 fois plus d'infestations, et, en présence d'une attaque sérieuse 3 à 4 fois plus d'infestations que les surfaces inférieures. Dans des essais entrepris en plein champ la protection par voie de pulvérisation des surfaces supérieures des feuilles était, en moyenne, aussi efficase que lorsque les feuilles furent pulvérisées des c?tés supérieur et inférieur. Toutefois, certaines variétés de pommes de terre d'une croissance étalée (King Edward par exemple) furent un peu mieux protégées par la pulvérisation de la surface supérieure des feuilles, alors qu'une pulvérisation combinée des c?tés supérieur et inférieur a donné des résultats légèrement meilleurs chez les variétés ayant un type de croissance fermée (Bintje). Dans des essais entrepris en laboratoire avec diverses grosseurs de gouttelettes sur des feuilles détachées de la plante, les gouttelettes les plus petites de bouillie bordelaise (M.M.D. 55μ) ont donné une protection nettement meilleure contre l'infestation que les gouttelettes plus grosses. Le traitement par pluie artificielle de feuilles pulvérisées par bouillie bordelaise a sensiblement amélioré la protection incomplète du fait probablement d'un redistribution des particules du fongicide appliqué sur les parties de la feuille restées non-protégées jusque-là. Desessaissimilaires avec Zineb ont donné des résultats plus irréguliers; dans la majorité des cas la pluie a corrompu l'efficacité de la protection.
Lecture held at the 4th International Informal Potato Conference at Lund (Sw.), August 1957. 相似文献
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多年来陷入低迷状态的我国甘蔗糖业,现在因大部分糖厂已转入民营,糖业架构重新组合。小规模糖厂合并,民营企业成立公司统辖多间糖厂成为集团机构,有较强大的经济实力。这样的重新组合,无疑将为我国甘蔗糖业带来机遇。 相似文献
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Effect of spreading method, application rate and dilution on ammonia volatilization from cattle slurry 总被引:2,自引:0,他引:2
J. P. FROST 《Grass and Forage Science》1994,49(4):391-400
Results from a series of five small-scale plot experiments which simulated different strategies for lowering ammonia volatilization following slurry application to grassland are reported. Strategies studied were band spreading, shallow-channel application, spike injection, rate of surface application and dilution. Volatilization was measured over the first 4 h following application with ventilated enclosures. Band spread slurry resulted in 0·4 of the volatilization that occurred from surface application of the same rate of slurry. The benefit of band spreading was shown to arise from higher application rates in the bands when compared with the same quantity of slurry spread over the surface. When surface-spread slurry was applied to the same depth of slurry as in bands, the volatilization per unit volume of slurry was the same. Shallow-channel application was more effective than band spreading and lowered volatilization per unit volume of slurry to <0·1 of that from surface-spread slurry. Spike injection was equally effective as shallow-channel application but, owing to perceived difficulties in machine design, construction and operation, was deemed impractical. Shallow-channel application has potential, though further work is required to optimize centre-to-centre spacing of the channels. As the application rate of surface-applied raw slurry increased, ammonia volatilization per unit volume of slurry applied decreased. Application at 50 m3 ha−1 resulted in 0·4 of the specific volatilization per unit volume of slurry that occurred at 6·3 m3 ha−1 . Within the dilution treatments, the amount of water added to the slurry was linearly and inversely related to volatilization. At a dilution of 0·9-1·2:1 water: slurry the specific volatilization per unit volume of slurry was 0·5 of that from undiluted slurry. 相似文献