萎凋工艺对福鼎白茶品质影响研究

为探讨影响福鼎白茶品质的关键因素,明晰不同萎凋工艺对其品质形成的影响,该试验以新采摘的成熟度、叶片色泽、形状大小基本一致的新鲜嫩叶为试材,研究萎凋工艺对福鼎白茶关键化学成分和感官品质的影响。结果表明自然萎凋和加温萎凋过程中水分含量均显著降低,其中自然萎凋失水速率要低于加温萎凋;茶多酚占总干物质的含量明显下降,加温萎凋过程茶多酚含量损失相比于自然萎凋要高;氨基酸占总干物质的含量随着萎凋时间延长有不同程度的升高。对萎凋叶和成品白茶进行感官评价,发现自然萎凋时间60 h、加温萎凋时间36 h时,萎凋叶具有最佳的外形,成品白茶也具有最佳的感官品质,且自然萎凋的品质要高于加温萎凋。     

Studies on freeze-withering in black tea manufacturing

In order to reduce the withering time during black tea manufacture, freeze-withering was attempted, which resulted in flaccid leaves with increased cell membrane permeability in a shorter period of time. The freeze-withered leaves had similar amounts of quality precursors as that of the conventionally withered leaves. The resultant black tea was better in quality than those manufactured without withering and after normal withering. Manufacturing of fresh leaves resulted in comparable levels of theaflavins, but the tea was not acceptable due to its harshness. Increased cell membrane permeability during freeze-withering showed that the leaf attained a sufficient degree of physical wither. The decreases in the levels of chlorophyll showed that chemical withering had also been achieved during freeze-withering, which is supported by the increased levels of caffeine.     

萎凋叶含水量对四川中小叶群体种工夫红茶品质形成的影响

目的探索萎凋程度对重庆工夫红茶品质形成的影响。方法以四川中小叶群体种为研究对象,分析比较了3个萎凋含水量:处理A(69.59%)、处理B(65.17%)、处理C(59.20%)萎凋叶红茶加工过程中色泽、多酚氧化酶(polyphenylene oxide, PPO)活性变化及对后续揉捻效果、生化成分、工夫红茶成茶品质形成的影响。结果随着萎凋水分的降低,萎凋叶L*, b*值呈下降的趋势, a*值呈上升的趋势, 4～6 h时均出现了与总体趋势相反的波动;加工过程中,各处理L*,b*值均呈下降的趋势,a*值在发酵前呈增高的趋势,干燥后值减小。成茶色泽L*a*b*值则均表现为处理A处理C处理B。加工过程中PPO活性呈先升后降的趋势,随萎凋程度的加重,高峰往后延迟且活性越强,处理C在发酵环节中活性最高。揉捻环节随着萎凋叶含水量的降低成条率越高,扁条率越低,细胞破碎率越高,处理C效果最好。内含物质随着萎凋叶含水量的减少,茶多酚先增后减,氨基酸先减后增,咖啡碱呈先减后增再减式起伏变化;水浸出物、可溶性糖差异不明显;成茶中处理C综合感官品质表现最好。结论萎凋叶含水量在60%左右时,有利于发挥四川中小叶群体种品种优势,加工出的工夫红茶品质良好。     

烘焙提香时间对工夫红茶品质的影响

为提高工夫红茶的甜香度,本文以山东夏季鲜叶加工的工夫红茶初制品为原料,在70℃的烘温下进行不同时间的烘焙提香处理,并通过感官审评、生化成分和香气分析方法研究其对工夫红茶品质的影响,结果表明:烘焙时间的长短不仅影响工夫红茶的香型和高低,而且也影响汤色和滋味,在本试验条件下,烘焙时间以1.0~1.5h的感官品质较好;此外,烘焙时间对工夫红茶各生化成分的影响不同,但对品质有利的生化成分以烘焙1.0h的茶样含量最高;随着烘焙时间的延长,工夫红茶香气的种类、含量以及组分比值发生显著变化,从而可以解释不同烘焙时间工夫红茶香型存在差异的原因。     

花香型工夫红茶的开发研究

为开发花香型工夫红茶,对品种选择和加工工艺进行初步研究。试验从9个湖南地方资源及部分外省品种中筛选出4个适制花香型工夫红茶的茶树品种和单株。在加工过程中,萎凋时用红外灯光照射,制得的工夫红茶带有花香,但花香持久性欠佳;原料选用具有一定成熟度的1芽2叶,有利于产品品质和香气的形成。     

云茶香1号不同萎凋工艺白茶的化学品质研究

为探明云茶香1号茶树品种不同萎凋处理白茶的香气特征物质。采用一芽二叶鲜叶（YC-R）为原料,室内萎凋（YC-T）和复式萎凋(YC-L)工艺加工白茶,利用感官审评、理化分析、GC-MS技术进行挥发性及非挥发性成分检测。（1）通过生化成分和感官审评分析表明表明云茶香1号加工白茶品质优质,儿茶素与可溶性糖存在差异,室内萎凋儿茶素、可溶性糖含量高,复式萎凋茶多酚、咖啡碱、氨基酸、黄酮含量高,外形得分低,香气得分高。（2）挥发性成分共鉴定出12大类,226种已知挥发性成分,144种显著差异。室内萎凋以果香的物质（E）-2-己酸丁酯、癸醛为主,复复式萎凋含有花香、果香、甜香、嫩香、香料香、蜜香、坚果香的物质较室内萎凋高。本研究不仅为云茶香1号茶树品种开发云南白茶新产品与香气特征成分之间的关系提供一定理论依据,更为云南白茶工艺的创新提供参考价值,促进云南茶产业多样化发展。     

Relationship between process of withering and aroma characteristics of black tea

Volatile flavour components (VFC), caffeine, crude fibre, ash and total water soluble solids (TSS) were analysed in orthodox and CTC black teas manufactured from normal and hard withered leaves. With the increase of wither, VFC, TSS and caffeine were found to increase but not crude fibre. The withering process in black tea manufacture appears to control the development of terpenoids, improving flavour quality in brewed tea.     

光质萎凋对不同茶树品种红茶品质的影响

本文以室内自然萎凋为对照,比较红光、黄光、蓝光的不同光强（1000、1500、2000 lx）对不同品种红茶感官品质和主要成分的影响。结果表明,与对照相比,光质萎凋能保持或提升福鼎大白茶、蜀永1号萎凋叶游离氨基酸含量,保持或提高了四川中小叶种红茶茶黄素含量;蓝光可提升蜀永1号、四川中小叶种红茶可溶性糖含量,还可降低福鼎大白茶、蜀永1号红茶茶褐素含量。黄光光强与福鼎大白茶红茶可溶性糖含量呈显著正相关,与四川中小叶种茶褐素含量存在极显著正相关,与蜀永1号萎凋叶和红茶茶多酚含量呈较大负相关,但不显著,而蓝光光强与四川中小叶种红茶可溶性糖含量呈较大正相关,但不显著。综合感官品质,福鼎大白茶红茶最佳的萎凋光质为1500 lx黄光、2000 lx黄光,茶红素含量较高,分别为2.211%、2.049%,而茶褐素含量较低,分别为3.081%、3.025%;蜀永1号红茶最佳的萎凋光质为1500 lx黄光,游离氨基酸含量最高,为2.8%;四川中小叶种红茶最佳的萎凋光质为1500 lx黄光、1500 lx蓝光,前者游离氨基酸含量较高,为3.4%,后者茶黄素含量较高,为0.280%,茶褐素含量较低,为2.937%。所以1500 lx黄光有利于提升所选品种红茶品质。     

不同干燥成形方式的白叶红茶品质分析

目的 研究不同干燥成形方式对白叶红茶品质的影响。方法 以白叶1号鲜叶为原料, 采用相同的萎凋、揉捻、初烘程序, 用不同的干燥做形方式制成不同形态的红茶,以感官审评结合理化分析的方法对不同形态的红茶进行了品质分析。结果 通过不同干燥成形方式获得了卷曲形、毛峰型、针形、扁形4种形态的红茶。4种红茶茶黄素、茶红素及氨基酸含量稍有差别,针形红茶茶黄素、类黄酮与氨基酸总量略高, 有利于提高其饮用价值,但4种红茶色、香、味感官品质总体接近。二次干燥(足火)-成形过程促使不同形态白叶红茶香气组成发生一定变化, 进而对红茶香型产生了细微影响,4种红茶以甜香为基本香型,卷曲型红茶香气特征偏于花香,扁形红茶略带果香。结论 毛火过程对白叶红茶品质的形成和固定具有关键意义, 干燥成形方式不改变总的香气特征, 但可使白叶红茶的具体香型发生细微分化。     

Effect of the withering process on volatile compound formation during black tea manufacture

The amount and composition of volatile compounds in the volatile oils were compared between non-withered tea and withered tea. Important differences in the aroma constituents were found in the amounts of E-2-hexenal, Z-3-hexanol ester, linalool and its oxides, and methylsalcylate. In withered teas, the amounts of Z-3-hexenol ester, linalool and its oxides, and methylsalcylate were much greater than in non-withered tea, but the E-2-hexenal content was higher in non-withered tea. From the results it was thought that the withering process has an important role in the formation of volatile compounds in tea shoots during black tea fermentation.     

一种崂山红茶冻凝胶食品的研究与开发

以崂山红茶和褐藻膳食纤维粉为主要原料,采用单因素试验和正交试验,结合质构仪测定指标和感官评价研制一种新型崂山红茶冻凝胶食品。以产品硬度、弹性和感官得分为指标,通过单因素和正交试验优化出崂山红茶冻的最佳配方是褐藻膳食纤维粉1.5%,成型剂添加量0.8%,红茶汤添加量60%(浸提比为1∶60),葡萄糖添加量10%。该条件下制作的产品具有很好的红茶风味,色泽均匀,口感细腻,弹韧性较好,感官评分最高,具有一定的营养价值和保健功能。     

萎凋时间对丹霞8号主要生化成分和挥发性成分的影响

以丹霞8号为试验材料,比较不同萎凋时间茶叶中生化成分和挥发性成分,探明其变化规律。结果表明:茶多酚含量在0～23h显著增加,23～32h显著降低。0～16h游离氨基酸含量显著增加,茶氨酸则显著降低;16～50h游离氨基酸和茶氨酸均显著降低。0～50h咖啡碱含量显著增加;可可碱显著降低;叶绿素a差异不显著。叶绿素b和类胡萝卜素含量在5～28h显著降低;28～50h显著增加。萜烯是5～32h萎凋叶主体挥发性成分,萜醇是0h和50h萎凋叶主体挥发性成分。主成分分析表明,0～50h萎凋叶的生化成分特征和香气轮廓呈规律变化,生化特征可分为0～16,23～28,32～50h3个阶段;香气轮廓分为0～9,16～23,26～32,50h4个阶段。16h和23h是茶叶萎凋过程中生化成分特征和香气轮廓变化的共有时间点。     

萎凋对茶鲜叶不同叶位叶绿素荧光特征参数的影响

目的研究萎凋对茶叶水分和叶绿素荧光参数的影响。方法采用叶绿素荧光仪Imaging PAM对福云6号7个萎凋时间点进行水分含量测定及叶绿素荧光测定。结果不同叶位叶片萎凋过程的水分含量与叶绿素荧光参数之间具有一定的内在联系。不同叶位之间的叶绿素荧光参数在萎凋后期呈显著差异;叶片水分含量与叶绿素荧光参数的初始荧光F_0、非光化学淬灭系数(non-photochemical quenching, NPQ)之间呈极显著负相关,与叶绿素荧光参数的最大光化学效率F_v/F_m、光合潜在活性F_v/F_0、电子传递效率(electrontransferrate,ETR)、实际光合量子产量Y(Ⅱ)之间呈极显著正相关。结论鉴于上述叶绿素荧光参数与叶片水分含量之间的相关性,初步认为F_0、NPQ、F_v/F_m、F_v/F_0、ETR和Y(Ⅱ)作为茶树鲜叶萎凋过程中水分胁迫程度的指标是可行的,对鲜叶萎凋过程的在线判断具有一定的意义。     

工夫红茶特征香气研究进展

红茶属全发酵茶,分为工夫红茶、红碎茶、小种红茶三大类,其中工夫红茶是中国特有和产量最大的红茶种类。香气是一影响茶叶感官品质组成的重要因子之一,不同产地的工夫红茶香气品质各异,表现出甜香、果香和花香等香型。茶叶香气一直是研究领域的重点。红茶中已鉴定的香气组分物质众多,且含量差异明显。,各组分之间的不同含量和比例形成了红茶各自独特的香气特征。工夫红茶是中国特有的红茶种类,不同产地的工夫红茶香气品质各异,表现出甜香、果香和花香等香型。本文简要综述了不同产地、不同茶树品种的工夫红茶香气中关键呈香物质及不同茶树品种和加工工艺对工夫红茶特征香气的影响,旨在为工夫红茶的加工技术提升和香气品质调控提供基础依据。     

An investigation into low‐temperature nitrogen plasma environment effect on the content of polyphenols during withering in made Kenyan tea

Low‐temperature nitrogen plasma (LTNP) was used to wither green tea leaf to study its effect on the polyphenol content. Using a dielectric barrier discharge chamber to provide the LTNP environment, green tea leaf was withered at various withering times. Made tea samples indicated that LTNP had an effect on polyphenol content. The highest polyphenol content of 78.56 mg g^?1 in made tea was attained in 1 h after which it showed a decreasing trend with increasing retention time. For comparison purposes, green tea leaf was also withered in nonplasma environments. Highest polyphenol content of 133.4 mg g^?1 in made tea was attained in a sample withered anaerobically in nitrogen gas at room temperature and atmospheric pressure for 18 h. In another sample, green tea leaf was directly macerated and dried without withering and fermenting and had polyphenol content of 101.91 mg g^?1 in made tea. These contents were compared with green tea 4, purple tea and oolong tea that are currently manufactured in Kenya.     

不同光波晒青对单枞茶品质的影响

晒青是乌龙茶制造的关键工序，但晒青易受天气条件的限制，导致了春季多雨与单枞茶鲜叶高产、质优，却难以发挥其优良品质的矛盾；用几种滤光材料，从日光中获得连续的光波段对单枞茶进行晒青，以期找出较佳的光波段，为人工模拟日光萎凋、实现全天候人工控制晒青提供理论基础。研究结果显示：与茶鲜叶相比，5种光处理晒青叶中品质成分含量变化趋势一致，但变化幅度不一致。去紫外光膜（透过的波长大于400nm）的处理晒青叶的多酚类物质保留量最多，而醚浸出物的减少量最大；黄色滤光膜（透过的波长大于520nm）的处理晒青叶中氨基酸的增加量最多；毛茶品质成分，以黄色滤光膜处理多酚类含量、氨基酸含量、水溶性糖含量、醚浸出物含量均为最高，其品质得分最高；去紫外光膜处理氨基酸含量、水溶性糖含量、醚浸出物含量均较其它处理低，而酯型儿茶素／简单儿茶素的值较其它处理高。全光谱和透红外膜（透过的波长大于720nm）处理毛茶中品质成分含量均居中，与毛茶感官审评结果中两处理品质相当一致。     

不同工艺不同品种坦洋工夫红茶品质的比较

选用坦洋菜茶、福安大白、金牡丹、金观音、梅占、白芽奇兰6种茶树鲜叶,以传统型工艺和花香型工艺分别制成不同风格的坦洋工夫红茶,以此为实验材料,通过生化成分分析、茶汤色差值及感官审评,探讨不同工艺不同品种坦洋工夫红茶品质的差异。结果表明:在工艺方面,传统型坦洋工夫滋味浓醇,茶汤橙红明亮,对应的理化特征表现为水浸出物、氨基酸、茶多酚、咖啡碱、茶红素含量均高于花香型,且差异显著,其中水浸出物相差0.84%,茶多酚相差0.71%,茶红素差值达1.24%;花香型坦洋工夫滋味醇爽,汤色橙黄明亮,香气馥郁持久,茶黄素和茶褐素含量均高于传统型,差值分别为0.03%与0.29%。在品种方面,福安大白茶与坦洋菜茶为坦洋地区传统品种,两种工艺制成的坦洋工夫均表现出茶汤滋味较醇厚,甜香持久的品质特征,而高香品种(金牡丹、金观音等)加工成的坦洋工夫花果香馥郁悠长,滋味甜醇但茶汤浓度略低。实验结果证明工艺与品种对坦洋工夫品质具有显著影响。     

基于变温发酵技术的黄金茶工夫红茶品质分析

该研究以保靖黄金茶1号1芽2叶鲜叶为原料试制工夫红茶,考察变温发酵(第一阶段40℃&第二阶段30℃)对黄金茶工夫红茶品质的影响.结果表明:变温发酵加工的工夫红茶色泽黑褐尚润,滋味甜醇、鲜爽,甜香尚高长,汤色红亮,叶底尚红匀;与恒温发酵相比,随着发酵程度的加深,茶汤颜色由红亮向红暗转变更明显,滋味由甜醇向纯和尚甜方向发展...     

响应面优化低糖滇红奶茶的配方

目的 通过响应面法优化低糖滇红奶茶的配方。方法 以滇红茶、全脂奶粉、零卡糖为主要原料,通过单因素分析结合响应面实验设计优化滇红奶茶配方,并分析产品的理化及卫生指标。结果 优化配方为：滇红茶汁50%、全脂奶粉15%、零卡糖10%、乳化剂0.22%、稳定剂0.2%,此时感官评分为87.83。滇红奶茶浅棕色稳定性好、质地均匀、浓稠恰当、细腻滑润无杂质,甜味适中茶香味与奶香香味协调无异味,经测定蛋白质含量(5.99±0.06)%、脂肪含量(3.38±0.02)%、茶多酚含量(320.6±2.25) mg/kg,微生物指标符合国家标准。结论 本研究开发了一种低糖健康的滇红奶茶,为滇红茶的深加工提供一定的实验依据。     

Variations of the chemical composition of clonal black tea (Camellia sinensis) due to delayed withering

The chemical composition of black teas (Camellia sinensis L) varies when the green leaf from which they are manufactured is withered physically to the same degree but for different periods. Caffeine contents progressively increase with prolonged withering time whereas theaflavins decrease due to prolonged withering. Although the sums of group I and group II volatile flavour compounds (VFC) decrease with prolonged withering time, the flavour index (expressed as group II VFC/group I VFC) increases due to prolonged withering. No significant changes were noted in the thearubigin levels with variation in withering time, but the tasters' evaluations were at a maximum for teas withered for 14 h. Subsequently the evaluation decreased with longer withering times.