茶叶色香味品质评价方法研究进展

随着时代的进步,传统茶叶品质评价方法的局限性日渐凸显,运用感官审评能快速鉴定茶叶品质特征,但容易受到主客观因素的影响,传统理化检测法虽然较为准确客观,但操作繁琐,且无法较好地反映茶叶整体品质。若在感官审评和理化分析基础上结合现代仪器和技术进行检测,能优势互补,取长补短,实现更为全面的茶叶品质评判。为此,本文从色泽、香气和滋味三个方面归纳了近年来在茶叶品质评价研究中所用的新方法,包括计算机视觉图像处理技术、可视化传感阵列技术、电子鼻技术、全二维气相色谱-飞行时间质谱技术、气相色谱-嗅觉测定技术、电子舌技术及近红外光谱测定技术,并对新技术在茶叶品质评价应用的发展趋势进行了展望。     

提高五峰毛尖茶品质的研究

五峰县毛尖茶有多种品牌，其制作工艺大同小异，成茶风格也少有差异，但各都有些欠缺。为了统一制作工艺，使成茶品质得到进一步提高，以原有工艺为基础，开展了以提高品质为中心内容的工艺试验研究，试验研究工作达到了预期的目的。     

中国茶叶外传及“茶之路”

<正> 1 中国茶叶向外的早期传播 中国茶叶的外传、有记载的最早是从我国的西北。据考证,在公元473—477年,土耳其商人以蒙古边界为中界地,通过以物易物方式,与我国进行茶的贸易。隋唐以后又与西边互市不绝。在唐代开始大量以马易茶,称为“茶马互市”,中国茶继续向西方传播,输往西亚和阿拉伯国家,其数量不比输往东方邻国少。唐时,中国商船独占广州至波斯湾的运输业。李隆基开元2年(公元714年)在广州特设市舶司管理商务,当时茶是商买商卖、“豪商”经营者甚多,阿拉伯,波斯等国外商人常把茶运回各地。但因东方的日本、朝鲜等国有学僧人来华,在保留佛教文化交流材料时,也保留了有关饮茶和种茶技术传播     

茶豆腐的制备

本研究利用茶叶、茶汁和黄豆制成具有茶香味的咖啡色的茶豆腐,丰富了豆腐品种,增加了豆腐的营养价值。     

中茶108、中茶302和中茶102的绿茶适制性及制茶品质

为了解从浙江省引进四川茶区的茶树良种中茶108、中茶302和中茶102的绿茶适制性和制茶品质,以四川茶区主栽品种福选9号为对照,研究3 个引进品种春梢（1 芽1 叶） 所制绿茶的主要成分含量、香气组分和感官品质。结果表明： 3 个引进品种所制绿茶内含物质较丰富, 水浸出物含量范围为（41.96±1.65）%～（43.94±0.93）%;咖啡碱含量范围在（3.92±0.06）%～（4.47±0.12）%。氨基酸含量为（4.78±0.16）%～（5.71±0.30）%,均显著高于福选9号;茶多酚含量为（19.89±0.68）%～（23.95±1.73）%,儿茶素含量为（8.38±0.08）%～（13.25±0.18）%,均显著低于福选9号;酚氨比值范围在3.48～5.01,也低于福选9号,因此,3 个供试品种具有适制绿茶,且茶汤滋味鲜爽、苦涩味低的物质基础。在中茶108、中茶302茶样中,检出香气成分37 种,中茶102中检出香气成分38 种。感官审评结果显示中茶108、中茶302所制的绿茶品质明显优于福选9号,中茶102则与福选9号品质相近。     

茶叶审评在眉茶出口贸易中的应用

绿茶是我国产量最多、消费量最大、出口量最多的茶类,其中眉茶更是出口拳头产品,销往100多个国家和地区.文章通过具体实例,结合实际工作经历简要介绍茶叶审评技能在眉荼出口贸易环节(成交、履约交货、售后结汇)、稳定市场等方面所起的作用,强调茶叶审评方式与消费国品饮习俗相融合,以期更好地开展茶叶出口贸易.     

食品感官评价技术在茶叶品质评价中的 应用研究进展

食品感官评价是用于唤起、测量、分析和解释通过视觉、嗅觉、味觉、触觉以及听觉而感知到的食品及其他物质的特征或者性质的一种科学方法,已经建立了科学的评价程序与方法,已广泛应用于产品的感官特征评价及产品鉴别、产品开发、市场调查等方面的研究。我国茶叶品类多样,产品风味独具特色。我国茶叶感官质量评价方法仍然是定级评价,采用食品感官评价技术建立更客观、更有效的产品感官质量评价体系十分必要。本文介绍了食品感官评价定义、方法及其在茶叶风味化合物研究,对典型茶叶(绿茶、红茶和乌龙茶)感官描述分析、典型茶叶感官术语及参考物、茶叶及茶产品消费者测试中的研究进展进行了综述,并提出了食品感官评价技术在茶叶感官品质评价研究发展方向。     

Effects of withering on the main physical properties of withered tea leaves and the sensory quality of congou black tea

To explore the relationship between the moisture content of withered tea leaves and their physical properties (i.e., elasticity, plasticity, flexibility, and texture) during withering, texture analyzer was employed to test the elasticity and flexibility of withered tea leaves with different moisture contents. The texture was evaluated by computer vision technology. The withered tea leaves with different moisture contents were used to process congou black tea, which was then subjected to sensory evaluation. Results showed that good elasticity, optimal flexibility, and plasticity were achieved when the moisture content of the withered tea leaves of Fudingdabai comprising two leaves and one bud varied arranging from 65.51 to 61.48%. The sensory evaluation of congou black tea revealed that moderate withering was better than long-term withering and that both moderate and long-term withering were better than no withering during processing. The moisture content was significantly correlated with the flexibility and plasticity of the withered tea leaves. Fresh tea leaves undergoing moderate withering with moisture content of 65.51–61.48% to process congou black tea, good tea shape and liquor color were achieved. This study provided new evidence that the moisture content of withered tea leaves significantly affected the quality of black tea.     

间歇真空发酵对辣木茶感官品质的影响

采用3因子2水平的正交试验设计,研究了发酵温度、发酵时间、间歇真空处理对辣木茶感官品质的影响。试验结果表明：影响辣木茶感官评分的因子重要性为发酵时间＞间歇真空条件＞发酵温度。发酵时间和间歇真空处理对辣木茶的感官评分分别有极显著（P＜0.01）和显著（P＜0.05）的影响。最佳的工艺组合为发酵温度35℃、发酵时间6 h、(-0.10 Mpa + 2 min)/2 h间歇真空处理,制得的辣木发酵茶感官评分达8.1分。     

烘焙提香条件对红茶感官品质及主要 生化成分的影响

目的 研究烘焙提香条件对红茶感官品质及主要生化成分的影响。方法 系统比较了不同烘焙温度及时间、不同提香温度及烘焙提香组合处理对红茶感官品质及主要生化成分的影响。结果 在3个烘焙温度下, 75 ℃烘焙3 h效果最好, 其次是70 ℃烘培5 h, 较低温度烘焙有助于主要生化成分的保留, 较高温度烘焙易产生热化学反应而导致内含物质部分减少, 但综合品质有所提升。在3个提香温度下, 110 ℃提香处理的红茶品质最好, 100 ℃提香次之, 120 ℃提香时温度过高有高火味, 主要生化成分会随提香温度的升高先增后降; 在3个烘焙及提香组合处理下, 组合75 ℃ 3 h+110 ℃处理效果最好, 该处理对茶叶品质提升有利。结论 掌握适当的烘焙或提香技术均能一定程度提高茶叶滋味及香气品质, 烘焙75 ℃ 3 h后经110 ℃提香2 min茶叶品质最好。     

不同水分工夫红茶贮藏过程中主要内含成分及感官品质变化研究

目的研究不同水分工夫红茶贮藏品质变化规律,为工夫红茶贮藏的适宜水分条件提供理论参考。方法系统比较不同水分工夫红茶(国家标准范围内)在自然贮藏条件下其主要内含成分及感官品质的变化。结果 1年贮藏期内,初始水分含量越低,含水率增长速度越快,总体上,茶叶初始水分含量高低决定贮藏过程中水分的高低。在短期贮藏(≤6月)时含水量越高的红茶中茶多酚、水浸出物保留量越多;长期贮藏(6月)时水分较低的红茶中茶多酚、水浸出物保留量越多。咖啡碱、可溶性糖在短期贮藏(≤6月)中水分含量适中的红茶中下降速度越慢;长期贮藏(6月)含水量较高的保留量越高。氨基酸含量在含水量越低的红茶中越高。初始水分含量高的红茶L*、a*、b*值均稍高于水分低的红茶。结论从综合品质的变化来看,本实验中以处理3含水率为5.93%的处理最好,处理2含水率为4.1%次之,处理1含水率为2.33%最差。     

Green tea from purple leaf coloured tea clones in Kenya- their quality characteristics

The Kenyan tea industry wishes to diversify its tea products, and in line with this, anthocyanin – rich teas were developed at the Tea Research Foundation of Kenya. These teas have purple-coloured leaves and the green colour is masked. In total, 12 accessions of the purple leaf coloured teas and 2 standard tea varieties were studied. Clones Hanlu and Yabukita are Chinese and Japanese tea varieties, respectively, known for good green tea, and they were used as reference standards. Little if any research had been done to characterize the quality of these purple leaf coloured teas and this study investigated their total polyphenols (TPP), catechins, caffeine, gallic acid and theanine. These are the major green tea quality parameters. Results showed that the new Kenyan tea clones had higher total polyphenols than had the reference standard tea varieties, which had 17.2% and 19.7% while the lowest among the Kenyan clones was 20.8%. On catechin quality index, K-purple and TRFK 91/1 showed high index values of 15.9 and 13.3, respectively, while clones TRFK 83/1 and 73/5 showed low index values of 0.74 and 1.0, respectively. Hanlu had the highest caffeine level with 2.42% while clones TRFK KS 3, TRFK KS 2 and TRFK 83/1 had relatively high caffeine levels among the purple leaf coloured teas, with 2.33%, 2.22% and 2.21%, respectively. Clone TRFK 73/5 had the lowest caffeine content, with 1.16%. Theanine analysis showed that most purple leaf coloured teas had more theanine than had the reference standard clones, except TRFK 83/1 and K-purple, which were lower than the reference standard clones. The implication of the green tea chemical quality parameters is also discussed. It is concluded that all the studied clones/varieties have above the minimum 14% of total polyphenols. Clones K-purple and TRFK 91/1 showed high green tea quality indices with the latter doubling with high levels of theanine; hence its highly recommended for green tea manufacture.     

茶叶感官检验工作中遇到的问题与建议

本文主要围绕茶叶感官检验工作中遇到的问题进行阐述和探讨, 主要包括: 标准中茶叶分类不明确; 评审术语含糊, 茶叶标准样品缺乏; 评语转化成评分时联系不强, 缺乏可操作性; 个别茶叶标准中的感官指标制定不科学等问题。针对以上情况, 建议进一步深化茶叶品质研究, 细化评价体系, 确保茶叶标准品的供应, 加强对茶叶感官审评人员的培训和考核, 并建议成立一个专门的机构对茶叶感官审评工作进行指导、监督和管理, 确保茶叶感官审评工作的顺利开展。     

滚筒式干燥机转速对茶叶感官品质影响的研究

通过对茶叶在干燥机滚筒内的运动轨迹的分析,研究干燥机滚筒的转速对茶叶感官品质的影响.结果表明,在滚筒转速为35～40 r/min时,绿茶感官品质明显提高.