四川引进茶树品种的红茶适制性及制茶品质初探

以四川茶区主栽并主产红茶的品种福鼎大白茶为对照,研究从浙江引进四川茶区的国家级茶树良种中茶302、浙农117的红茶适制性和制茶品质。结果表明：中茶302、浙农117的春、夏梢鲜叶的水浸出物含量范围为37.19%～42.19%、茶多酚含量为20.27%～29.50%、儿茶素总量为132.95～157.76 mg/g,均显著高于对照福鼎大白茶;酚氨比（茶多酚与氨基酸的比值）为4.25～9.81,也高于对照福鼎大白茶,具有红茶适制性;所制红茶内含物丰富,其特征成分茶多酚含量为11.81%～19.61%、儿茶素总量为18.69～39.13 mg/g;茶汤的茶黄素、茶红素含量均较高,分别为0.63%～0.74%、8.66%～9.90%,且茶红素/茶黄素范围为12.97～14.03,因此其具有滋味浓强、汤色红亮的物质基础。2 个引进品种红茶均检出醇、醛、酮、酯、烯、烷烃类及未知化合物等7 类50 种香气成分,其中醇类香气物质含量最高,相对含量分别为64.06%、67.23%,芳樟醇及其氧化产物、香叶醇等香气主体成分含量也显著高于对照。感官评价结果显示,2 个引进品种所制红茶品质较优异且相当,均优于对照福鼎大白茶所制红茶的品质。     

高氨基酸保靖黄金茶1号的生化特性及绿茶适制性研究

以福鼎大白茶为对照,对湖南引入川西茶区的保靖黄金茶1号品种的鲜叶以及春梢所制绿茶的主要生化成分含量、香气组分进行了分析测试,并进行感官审评。结果表明:春夏秋季新梢鲜叶水浸出物、氨基酸、咖啡碱、茶多酚和儿茶素含量范围分别为39.33%~46.34%、2.86%~6.35%、3.61%~4.09%、18.12%~24.74%、13.91%~20.29%,均显著高于对照福鼎大白茶;酚氨比值范围为2.80~8.65,低于对照;儿茶素品质指数均高于对照。黄金茶1号春梢独芽、一芽一叶与一芽二叶新梢所制的绿茶样主要生化成分含量与对照相比也有相同的趋势。黄金茶绿样检测出45种香气组分,以醇类为主,其次是烯烃类和酯类,其中,黄金茶独芽和一芽二叶所制绿茶中,具玫瑰香气的香叶醇含量分别比对照高115.01%、164.71%。这些结果显示,黄金茶1号引种四川后,保持了高氨基酸含量的特性,具有滋味鲜爽浓厚、栗香高长的生化物质基础。感官审评结果也显示,黄金茶1号品质优于对照福鼎大白茶。     

不同采摘季节工夫红茶品质的研究

以不同季节(春、夏、秋)采摘的茶树鲜叶为实验材料,按照工夫红茶常规制造工艺(萎凋、揉捻、发酵和干燥)制成红茶,分析了茶多酚、游离氨基酸、茶红素(TR)、茶黄素(TF)、茶褐素(TB)含量,采用顶空固相微萃取方法结合气质联用技术鉴定了不同采摘季节工夫红茶中香气物质种类,并进行了感官审评。结果表明,不同季节的工夫红茶中,春季红茶茶多酚含量最高(19.19%~22.49%),游离氨基酸含量最高(2.73%~2.91%),茶褐素含量最低(6.73%);夏季和秋季红茶各项指标接近,茶多酚含量低于春季,为16.77%~18.67%,游离氨基酸也低于春季,含量为2.28%~2.46%;而夏季的茶黄素和茶红素都高于秋季和春季,含量为7.97%。不同季节工夫红茶香气物质都主要包含醇类、醛类、酯类、酮类、烯类和烷烃类等。其中,醇类物质是工夫红茶的主要香气物质,占香气总量的44.86%~60.79%。香叶醇、水杨酸甲酯、β-芳樟醇、苯乙醇、苯甲醛和苯乙醛是不同季节工夫红茶的主要呈香物质组分。香叶醇含量在春季占绝对优势,其中春季香叶醇含量最高,能达到40%以上,而夏季、秋季呈明显降低趋势;水杨酸甲酯和芳樟醇类春季含量较低,从夏季开始则有增加趋势。感官审评结果表明,春季工夫红茶评分最高(92.0分),秋茶居中(89.4分),夏茶次之(86.3分)。     

梅占红茶、白茶品质差异分析

为探究梅占红茶、梅占白茶的品质差异,以梅占鲜叶为原料分别加工成红茶和白茶,并进行感官品质审评与理化分析.结果表明:梅占红茶香气呈甜花香,滋味甜醇;梅占白茶香气呈清花香,滋味醇爽.梅占红茶茶黄素、茶红素、茶褐素含量显著高于梅占白茶;梅占白茶茶多酚、游离氨基酸含量显著高于梅占红茶(P<0.05).共鉴定出的56种香气成分,...     

长江中下游产区红茶品质分析

针对长江中下游不同产茶区的红茶进行感官品质评价,结合理化成分和香气成分分析,提取滋味和香气品质相关特征信息。结果表明:长江中下游区域红茶在感官品质上呈现甜香、薯甜香、甜醇等香气、滋味等特征。品质成分中水浸出物、咖啡碱、萜烯醇含量均较高,大部分产区茶红素与茶黄素的比例为1:10~1:13之间,是长江中下游区域红茶汤色红亮、滋味醇厚、甜香持久的物质基础。其中湖北茶区红茶的可溶性糖、茶红素等含量较高,是茶汤红亮、滋味甜醇的物质基础,湖南茶区红茶的水浸出物、茶多酚、咖啡碱、黄酮、儿茶素总量、茶黄素及茶红素含量较高,是其茶汤深红、滋味浓厚的物质基础;浙江、安徽茶区红茶的氨基酸和可溶性糖含量较高,是其茶汤甜醇的物质基础。醇类和醛类是主要的香气化合物,芳樟醇、氧化芳樟醇、香叶醇、苯甲醛、苯乙醛、2-甲基丁醛、2-己烯醛、β-环柠檬醛、水杨酸甲酯和β-紫罗酮等共同构成了红茶甜香、糖香及花香的物质基础,另外2-正戊基呋喃、2-乙基呋喃和1-乙基-2-甲酰吡咯呈现坚果、焦香等风味,对红茶的焦糖香形成有着直接影响。     

婺源茶树群体种的适制性研究及品质评价

以婺源茶树群体种为研究对象,参照当地茶叶制作工艺制得婺源名优绿茶（婺源仙枝、婺源茗眉、婺源特供）、婺源红茶和婺源白茶5种成品茶,并对其进行主要生化品质分析、挥发物检测和感官审评。结果表明,5种茶的水浸出物、茶多酚、可溶性糖、游离氨基酸、没食子酸和咖啡碱的含量均符合该类茶的品质特点,同时表没食子儿茶素没食子酸酯（epigallocatechin gallate,EGCG）和儿茶素（catechin,C）的含量较高。感官审评和挥发性组分分析发现,婺源仙枝含有较高比例的顺-己酸-3-己烯酯和β-芳樟醇并表现出“栗香”的香气特点,婺源茗眉及婺源特供则含有较高含量的香叶醇、β-芳樟醇、吲哚、水杨酸甲酯并呈现出“清香”的香气特点。     

3个茶树品种“湖红”工夫红茶适制性比较研究

目的筛选"湖红"工夫红茶适制性较好的茶树品种。方法选取碧香早、黄金茶2号、槠叶齐3个茶树品种为材料,采用传统的红茶加工工艺制成红条茶;通过感官审评和品质成分动态分析,测得3个茶树品种制作的红茶各个工序阶段茶叶中水浸出物、氨基酸、咖啡碱、茶多酚、茶红素、茶黄素、茶褐素的含量,对其主要理化成分动态变化进行分析。结果研究结果表明,感官审评中碧香早和槠叶齐品种做出的茶样香气、汤色与滋味都较好,理化分析中碧香早做出的茶样中茶多酚含量和茶红素含量最高,分别为14.0%和2.19%。结论综合比较,碧香早的"湖红"工夫红茶适制性较好。     

贵州珠形绿茶‘金牡丹’和‘铁观音’品质研究

为了解乌龙茶品种的贵州珠形绿茶适制性,以贵州主栽品种福鼎大白茶为对照,对国家级茶树良种‘金牡丹’和‘铁观音’春、夏梢所制珠形绿茶进行主要生化成分测定及感官审评。结果表明:‘金牡丹’和‘铁观音’的春、夏茶（珠形绿茶）的水浸出物、茶多酚、氨基酸和咖啡碱含量为43.54%±0.78%～46.14%±0.42%、21.27%±0.60%～27.65%±0.11%、3.37%±0.18%～4.83%±0.09%和3.11%±0.07%～4.35%±0.06%,其中春茶的水浸出物、咖啡碱、茶多酚均显著高于对照,而氨基酸总量均显著低于对照（P<0.05）。其夏茶除茶多酚显著高于对照外,均与对照无显著差异（P>0.05）。感官审评发现,‘金牡丹’春茶品质优于对照,‘铁观音’低于对照。‘金牡丹’和‘铁观音’夏茶品质得分与对照相当。‘金牡丹’和‘铁观音’均为清香带花香,滋味则更浓醇。综合主要生化成分及感官审评,珠形绿茶‘金牡丹’和‘铁观音’香高馥郁带花果香,滋味浓醇。其鲜爽味物质不及‘福鼎大白茶’,但浓厚（强）度的物质含量高于对照。     

茶树新品系苦茶21-1主要品质成分分析

以新品系苦茶21-1为供试材料,以国家级良种福鼎大白茶、槠叶齐和省级良种潇湘1号为对照,测定4个品种红、绿茶的主要品质成分,并结合感官审评进行分析。实验结果表明,新品系苦茶21-1所制绿茶,外形条索弯曲紧细、色泽绿润,汤色黄绿明亮,果香浓郁,滋味鲜爽,香气和滋味尤其突出;所制红条茶外形乌黑油润,汤色红艳明亮,香气甜香醇正,滋味甜醇,"冷后浑"明显,乳状络合物呈橙黄色。红、绿茶主要品质成分含量分别为水浸出物38.26%、44.22%,茶多酚19.40%、30.38%,游离氨基酸5.01%、5.04%,咖啡碱5.11%、5.09%;红、绿茶中咖啡碱含量均高达5%以上,可能属于茶树高咖啡碱优异资源;绿茶儿茶素品质指数高于福鼎大白茶,红茶TR/TF值为11.2,茶黄素和茶红素比例优。茶树新品系苦茶21-1具有加工优质绿茶和优质红茶的品种特征,尤以红茶品质突出,有较高的红茶育种价值。     

夏季鲜叶工夫红茶适制性研究

为探究茶树品种对夏茶制作红茶品质的影响,从汤色、香气、滋味3个方面着手,借助色差计、分光光度计、氨基酸分析仪、气相色谱-质谱联用仪和超高效液相色谱串联高分辨质谱仪,分析15个茶树品种的夏茶制得工夫红茶的感官品质和生化成分。结果表明:所制工夫红茶的汤色以橙红为主,滋味以醇为主,香气品质差异较大,其中乌龙茶具有甜香与花香。茶黄素、茶红素和茶褐素对汤色与滋味影响均较大,其含量越高,汤色得分越高。金牡丹和金萱红茶中香叶醇含量较高,它和橙花醇与香气得分呈显著正相关。红茶制作过程中,金萱、金牡丹、铁观音和菊花春中儿茶素变化较大,而茶黄素生成较多,这与生物酶活性和儿茶素含量有关。萎凋阶段,中茶108、金萱和金牡丹氨基酸含量大幅增加,在红茶中大量保留。结合感官与成分分析可确定:由金萱和金牡丹夏茶制得工夫红茶的汤色、滋味和香气均较好。多数品种的夏茶可加工工夫红茶,其中尤以乌龙茶更佳,可优先作为夏茶工夫红茶的开发品种。     

夏秋红茶的再加工与冷泡茶制备研究

目的 探索利用夏秋红茶再加工制作冷泡茶的可行性和最佳工艺条件。方法 利用纤维素酶处理夏秋红茶,通过单因素实验和正交实验筛选最佳酶解条件,测定处理前后红茶中主要化学成分和挥发性风味物质变化,并对其冷泡性能进行评价。结果 优化获得了夏秋红茶再加工的工艺条件为:纤维素酶添加量为1.2 kU/g,料液比为5:8(g:mL),处理时间为24h,处理温度为25℃。纤维素酶加工后茶叶中的主要滋味物质和风味物质含量以及冷泡性能等品质指标均有所提高。冷泡茶汤中的可溶性总糖含量由4.33%升高至9.35%,水浸出物含量由26.64%升高至35.73%。在挥发性风味物质方面,加工后茶叶中苯甲醇(芳香、果香)、苯乙醇(玫瑰花香、蜜香)和水杨酸甲酯(清香、花香)等特征香气物质的相对含量升高。冷泡性能方面,加工后的红茶水浸出物冷泡溶出大幅增加和可溶性总糖则可完全冷泡溶出,产品适于冷泡饮用。结论 本研究通过纤维素酶再加工提升夏秋红茶品质,制备冷泡茶,不仅能实现夏秋茶资源的充分利用,也为冷泡茶的生产提供了稳定的原料供应。     

Ultrafiltration isolation,physicochemical characterization,and antidiabetic activities analysis of polysaccharides from green tea,oolong tea,and black tea

Both fermentation degree and preparation method of polysaccharides could influence the bioactivity of tea polysaccharides. The aim of this study was to compare the physicochemical characterization and biological activities of the polysaccharides isolated by ultrafiltration method from three kinds of tea (green tea, oolong tea, and black tea). The bioactivities of tea polysaccharide fractions were compared from four aspects, including antioxidant activities, antiglycation activities, α-glucosidase inhibitory capability, and hypoglycemic effects on L6 myotubes. Results showed that six polysaccharides (GTPS1, GTPS2, OTPS1, OTPS2, BTPS1, and BTPS2) had different contents of neutral sugar and uronic acid, and they showed different morphologies. Six polysaccharides were composed of the seven monosaccharides with different molar ratios. BTPS1 exhibited the highest DPPH scavenging activity and hydroxyl radical scavenging activity (P < 0.05), and BTPS1 also showed the strongest antiglycation inhibitory effects (P < 0.05). BTPS1 and BTPS2 showed strong inhibitory capacity on α-glucosidase and hypoglycemic effects in L6 skeletal muscle cells. The result suggested that the degree of fermentation of tea could improve their bioactivities (BTPS > OTPS >GTPS), and TPS1 with smaller molecular weight distribution showed higher bioactivities than TPS2. This study can provide a scientific foundation for the application of tea polysaccharides and related functional products.     

K and Ca content of fresh green tea, black tea, and tea residue determined by X-ray fluorescence analysis

Summary X-Ray fluoresence (XRF) can be successfully used for the qualitative and quantitative elemental analysis of various agricultural products. Its simplicity, high throughput and the possibility of automation make it useful for screening large numbers of samples. The K and Ca content of 138 samples of fresh green tea, black tea and black tea residues were determined by applying the XRF system. Such a method of mineral analysis of food products is not very common. Tea from different teagrowing areas of Turkey, green tea of different shooting periods, black tea processed at different tea plants and tea residues from these black tea were analysed. The K content of green tea, processed black tea and tea residues after brewing were found to have ranges of 19,049–26,254 mg/kg, 21,904–26,883 mg/kg and 9,468–13,778 mg/kg, respectively. In the same samples the Ca content was determined as 3,580–4,799 mg/kg, 3,370–4,823 mg/kg, and 3,743–5,733 mg/kg, respectively. These findings were compared with the results of atomic emission techniques and it was concluded that the XRF system could be effectively used for quantitative analysis of the K and Ca content of tea samples.

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Die Bestimmung des K- und Ca-Gehaltes von frischem Tee, schwarzem Tee und Teerückstand durch die X-Ray-Fluoreszenz-Technik

Zusammenfassung Mit der X-Ray Fluoreszenztechnik können die qualitativen und quantitativen Bestimmungen der Mineralstoffe in verschiedenen Produkten erfolgreich durchgeführt werden. Mit dieser Methode wurde der Ca- und K-Gehalt von 138 Proben untersucht, und zwar frischer Tee, schwarzer Tee und Teerückstand. Diese Methode ist in der Lebensmitteltechnologie, insbesondere bei der Mineralstoffbestimmung nicht üblich. Die Teeproben stammten aus verschiedenen Teeanbaugebieten der Türkei. In dieser Arbeit wurden die Wirkung der Sproßperiode, der Verarbeitungstechnik und des Anbaugebietes auf den Ca- und K-Gehalt der Teeproben untersucht. Der durchschnittliche K-Gehalt betrug: in frischem Tee 19049–26254 mg/kg, in schwarzem Tee 21904–26883 mg/kg, in Teerückstand 9468–13778 mg/kg; der Ca-Gehalt 3580–4799 mg/kg, 3370–4823 mg/kg und 3473–5733 mg/kg.

     

黑茶中茶多酚的醇水超临界CO_2流体联合提取

以自制黑茶为研究对象,分别采用超临界CO2萃取法、醇水浸提法及醇水浸提-超临界CO2联合萃取法对茶样中的茶多酚进行提取,用正交实验法优化了提取条件,以没食子酸为标准品,在765nm处用紫外可见分光光度法检测产品中茶多酚的含量,计算了茶多酚的得率及萃取样中产品的纯度,并对三种产品的DPPH·清除率进行了比较。结果表明:3种方法中醇水-超临界CO2联合萃取法的得率和纯度最高。联合浸提最优条件为:先用乙醇浓度80%,料液比1∶10g/m L,60℃下浸提2.0h,然后25MPa,50℃下超临界CO2萃取时间2h。茶多酚的得率为6.36%±0.81%,产品纯度为:41.22%±3.19%。产品对DPPH·的清除率为90.64%±0.0187%。该方法绿色环保,未添加任何有害溶剂,为黑茶饮品的进一步研究开发提供参考。     

绿茶、乌龙茶、红茶贮藏过程中品质劣变机理及保鲜技术研究进展

茶叶的生产具有较强的时效性和季节性,且茶叶疏松多孔,长期贮藏过程中极易受环境影响而变质。作为广受消费者青睐的世界三大饮料之一,保持其贮藏品质对提高茶叶商品价值,推进我国茶产业的发展具有重要意义。近年来针对茶叶贮藏过程中的品质变化原因兴起了各种保鲜技术。该文通过讨论茶多酚、氨基酸、维生素C、叶绿素、脂质等物质的氧化降解,总结了绿茶、乌龙茶、红茶等的陈化劣变机理,同时概述了水分、温度、氧气、光照等影响茶叶贮藏品质的4大因素,并详细阐述了运用干燥、冷藏、脱氧、生物保鲜剂等方法进行茶叶贮藏的相关技术,最后展望了茶叶保鲜的深入研究方向,以期为相关茶叶保鲜新技术的研究提供科学理论指导。     

Effects of tea leaf waste of green tea,oolong tea,and black tea addition on sudangrass silage quality and in vitro gas production

This study evaluated the fermentation characteristics and in vitro gas production of sudangrass (Sorghum sudanese) silage with tea leaf waste of green tea, oolong tea and black tea added. All types of tea leaf waste contain large amounts of nitrogen (N) and tannins, and a small amount of low‐water‐soluble carbohydrates. Sudangrass was preserved without (control) and with green tea waste (GTW), oolong tea waste (OTW) or black tea waste (BTW) at rates of 50, 100 and 200 g kg^?1 fresh matter in laboratory silos. The pH and butyric acid levels were significantly lower in GTW at all rates and in OTW at the 200 g kg^?1 rate, whereas those levels were high in the control and BTW‐treated silage. Lactic acid level was appreciably higher in GTW‐ and OTW‐treated silage than the control and BTW‐treated silage. The addition of all types of tea waste increased the total N and tannins of the silage, whereas the acid detergent insoluble N was increased in the OTW‐ and BTW‐treated silage. GTW treatment increased gas production within a 96‐h period compared with the control, whereas OTW and BTW additions at 200 g kg^?1 rates caused lower gas production. It is concluded that the fermentation characteristics and feed value of the silage incorporating with tea leaf wastes are different for these types of tea leaf. Among the three kinds of tea waste, GTW is the most valuable material as a silage additive. Copyright © 2004 Society of Chemical Industry     

高效液相色谱-二极管阵列法检测四川绿茶、黄茶、黑茶、红茶和青茶中甲基化儿茶素含量

采用高效液相色谱-二极管阵列检测法(HPLC-DAD)对四川省雅安、成都、乐山、宜宾、绵阳23家企业生产的绿茶、黄茶、黑茶、红茶和青茶中48个茶样的(-)-表没食子儿茶素-3-O(3-O-甲基)没食子酸酯(EGCG3″Me)含量进行了比较研究。结果表明:青茶EGCG3″Me含量最高,在3.14~6.08 mg/g之间,平均值为4.40 mg/g;黑茶EGCG3″Me含量在0~1.72 mg/g,平均值为0.35 mg/g;绿茶和黄茶中EGCG3″Me含量较低;绿茶中含量在0~0.39 mg/g之间,平均值为0.10 mg/g;黄茶中含量在0~0.09 mg/g之间,平均值为0.05 mg/g;红茶中未检出。各茶类间EGCG3″Me含量差异显著,主要原因在于加工所用鲜叶原料(品种、采摘标准等)及加工工艺等不同。建议易过敏人群应适当饮用青茶。     

黑大豆茶的研制

以黑大豆为原料,经浸泡、分选、发芽、烘烤等工艺生产了一种具有独特风味和较高营养的豆茶,为黑大豆资源的开发利用开辟了一条新途径。     

Comparison of black tea aromas of orthodox and CTC tea and of black teas made from different varieties

Volatile compounds obtained from orthodox black tea and CTC tea were analysed by a g.c.-m.s. method. A difference in the contents of cis-3-hexenol, linalool, linalool oxides, methylsalcylate and geraniol was found between the two types of tea. It was thought that the difference in the contents of volatile compounds might be produced by the individual manufacturing processes. A typical difference in the contents of linalool and geraniol was observed in volatile oils of black teas made from cultivars of v. assamica and hybrids of assamica and sinensis. The difference in the volatile compounds in black teas may be related to the genetic variation.     

Characterisation of white tea – Comparison to green and black tea

An overview is given on the manufacture of the different types of tea along with the most important phenolics present in tea and methods of analysis. Compositional data are presented for green, white and black teas. A differentiation of green and black tea by using the ratio between total phenolics and sum of the major catechins seems to be feasible. For white tea there is no general accepted definition. Possible approaches are geographic origin, the botanical variety and the manufacture or the appearance. The differentiation between green and white teas by the ratio mentioned above is not possible.