安溪铁观音成分 酚氨比 茶多酚 氨基酸

“酚氨比”，通俗说就是茶多酚与氨基酸的比值,鲜叶或成品茶中茶多酚总量与氨基酸总量之比。茶多酚和氨基酸是茶叶品质成分中含碳化合物和含氮化合物的突出代表。其比值反映了铁观音茶叶两大主要品质成分的配比情况，可在相当程度上判定鲜叶的品质属性及成茶品质的优劣。适制绿茶的品种，要求酚氨比较低；适制红茶的品种则要求酚氨比较高；适制乌龙茶茶的品种则要求酚氨比较适中。其值又是成品茶茶汤滋味醇度的重要指标。

茶

多

酚

茶汤中的酚类物质以儿茶素含量最高。酯型儿茶素呈苦涩味，收敛性强。一些茶汤入口引起的涩味主要是由于酯型儿茶素与口腔黏膜蛋白质反应形成不透水物质，引起收敛。从感官的角度讲，涩味也是刺激触觉神经末梢产生的。而简单儿茶素主要是产生茶汤中令人爽口的感觉。有研究认为，茶多酚含量在20%以内时，滋味得分与茶多酚含量呈显著正相关；茶多酚含量在20%-24%范围内，仍能保持茶汤浓度、醇度、鲜爽度的和谐统一。茶多酚含量进一步增加时，尽管茶汤浓度增大，但鲜醇度降低，苦涩味也加重。有研究认为，儿茶素总量与茶汤滋味评分的相关系数是0.929,EC（表儿茶素）的相关系数是0.729,EGC（表没食子儿茶素）的相关系数是0.704,EGCG（表没食子儿茶素没食子酸酯）的相关系数为0.850,ECG（表儿茶素没食子酸酯）则为0.876。茶多酚对茶品质的影响是复杂的，由于其含量较高，是决定茶汤浓度的主要物质。不能用简单的正相关或负相关来断言茶多酚对茶汤滋味的影响，应该从茶多酚的可溶性程度，茶多酚绝对含量，茶多酚与其它呈味物质特别是氨基酸比例的大小等多个角度综合分析。

氨

基

酸

铁观音滋味要求醇和鲜爽，其中甘和鲜爽的口感都与茶叶中的氨基酸有关。茶叶中的氨基酸种类很多，呈现的特点也不尽相同。其中含量最高的是茶氨酸，这也是茶叶中独有的一种氨基酸。茶叶中含量较高的氨基酸主要有谷氨酸、天冬氨酸、精氨酸、谷酰胺、天冬酰胺等。就每一种氨基酸的味质特点来说，并非所有氨基酸都呈鲜味，大多数氨基酸是呈甜味。据有关资料报道，L型氨基酸大多数呈苦味，少数呈甜味或鲜味；D型氨基酸均呈甜味。自然界中构成蛋白质的氨基酸都是L型的，因此，茶叶中蛋白质水解得到的氨基酸给予茶汤的味质多为苦味。茶叶中游离氨基酸的构型虽难断定，可以肯定它给予茶汤的味质决非仅为鲜味，也有苦味和甜味。这些不同味质经过不同的配比和综合作用，便构成了茶汤的各种不同味感特点，这也是为什么我们喝到的铁观音有的会苦后回甘。

酚氨比关于铁观音茶汤滋味的协调性

上文有介绍到，茶多酚是铁观音茶叶中的主要物质之一，它呈苦涩味。而氨基酸也是茶叶品质成分中含氮化合物的突出代表，是形成铁观音茶汤鲜爽度和香味的主要物质。

理论上氨基酸和茶多酚这两种成分含量高且比例协调是最好的。一般来说，二者比例关系如下：

1、茶多酚高，氨基酸含量高，铁观音茶叶味浓，鲜爽，不涩。

2、茶多酚含量低，氨基酸含量高时，味淡，鲜爽，不涩。

3、茶多酚含量高，氨基酸含量低时，味浓，不鲜爽，苦涩。

"Phenol-ammonia ratio", in layman's terms, is the ratio of tea polyphenols to amino acids, the ratio of the total amount of tea polyphenols to the total amount of amino acids in fresh leaves or finished tea. Tea polyphenols and amino acids are prominent representatives of carbon- and nitrogen-containing compounds in tea quality components. Its ratio reflects the ratio of the two main quality components of tea, and can determine the quality attributes of fresh leaves and the quality of finished tea to a considerable extent. Varieties suitable for making green tea require relatively low phenolic ammonia; varieties suitable for making black tea require relatively high phenolic ammonia; varieties suitable for making oolong tea require moderate phenolic ammonia. Its value is also an important indicator of the taste and mellowness of the finished tea tea soup.

Tea

many

phenol

The content of phenolic substances in tea soup is highest in catechins. Ester catechins are bitter and astringent and have strong astringency. The astringency caused by the entrance of some tea soups is mainly due to the reaction of ester catechins with oral mucosal proteins to form impermeable substances, causing convergence. From a sensory point of view, astringency is also produced by stimulating tactile nerve endings. The simple catechins are mainly responsible for the refreshing feeling in the tea soup. Some studies believe that when the content of tea polyphenols is within 20%, the taste score is significantly positively correlated with the content of tea polyphenols; when the content of tea polyphenols is within the range of 20%-24%, the concentration, mellowness and freshness of tea soup can still be maintained. degree of harmony. When the content of tea polyphenols increased further, although the concentration of tea soup increased, the freshness and mellowness decreased, and the bitterness and astringency also increased. Some studies believe that the correlation coefficient between the total amount of catechins and the taste score of tea soup is 0.929, the correlation coefficient of EC (epicatechin) is 0.729, the correlation coefficient of EGC (epigallocatechin) is 0.704, and the correlation coefficient of EGCG (epigallocatechin) is 0.704. The correlation coefficient was 0.850 for catechin gallate) and 0.876 for ECG (epicatechin gallate). The influence of tea polyphenols on the quality of tea is complex, because of its high content, it is the main substance that determines the concentration of tea soup. The influence of tea polyphenols on the taste of tea soup cannot be judged by simple positive or negative correlation. The degree of solubility of tea polyphenols, the absolute content of tea polyphenols, the ratio of tea polyphenols to other taste substances, especially amino acids, etc. Comprehensive analysis from multiple angles.

ammonia

base

acid

The taste of Tieguanyin requires mellowness and freshness, and the sweetness and freshness of the taste are related to the amino acids in tea. There are many types of amino acids in tea, and the characteristics are not the same. The highest content is theanine, an amino acid unique to tea. The amino acids with high content in tea mainly include glutamic acid, aspartic acid, arginine, glutamine, asparagine and so on. As far as the taste characteristics of each amino acid are concerned, not all amino acids are umami, and most amino acids are sweet. According to relevant data reports, most L-type amino acids are bitter, and a few are sweet or umami; D-type amino acids are all sweet. The amino acids that make up protein in nature are all L-shaped, therefore, the amino acids obtained by hydrolysis of protein in tea give the tea soup a bitter taste. Although it is difficult to determine the configuration of free amino acids in tea, it is certain that the taste it imparts to the tea soup is not only umami, but also bitter and sweet. These different flavors, through different ratios and comprehensive effects, constitute various taste characteristics of tea soup, which is why some of the Tieguanyin we drink will be bitter and sweet.

The coordination of phenol to ammonia ratio on the taste of Tieguanyin tea soup

As mentioned above, tea polyphenols are one of the main substances in tea, and they have a bitter taste. Amino acids are also prominent representatives of nitrogen-containing compounds in tea quality components, and are the main substances that form the freshness and aroma of Tieguanyin tea soup.

In theory, amino acids and tea polyphenols are the best with high content and coordinated proportions. Generally speaking, the proportional relationship between the two is as follows:

1. Tea polyphenols are high, amino acid content is high, tea leaves are strong, fresh and not astringent.

2. When the content of tea polyphenols is low and the content of amino acids is high, the taste is light, fresh and not astringent.

3. When the content of tea polyphenols is high and the content of amino acids is low, the taste is strong, not fresh, and bitter.