铁观音茶叶中的内含物质 茶多酚、氨基酸、咖啡碱、糖类、蛋白质、果胶、芳香物质、叶绿素

铁观音茶叶中的内含物质多种多样，目前已经统计出的就有140多种。总的来说，茶叶的主要内含物有茶多酚、氨基酸、咖啡碱、糖类、蛋白质、果胶、芳香物质、叶绿素等。安溪铁观音茶叶的品质特征即是这些内含物质的在外表现。

其中叶绿素、叶黄素、叶红素等物质决定了茶叶的颜色，绿茶中铁观音茶叶的原有物质保留的最为全面，含有大量的叶绿素，因此绿茶呈现出清汤绿叶的品质特征。红茶中的茶多酚类物质发生了酶促氧化反应，生成了叶黄素和叶红素，叶红素堆积在一起呈现出红茶干茶乌黑油润的品质特征。叶黄素被较多的溶解在茶汤中，所以红茶的茶汤呈金黄色。黑茶中普遍含有较多的叶红素，因此黑茶的茶汤多是红艳透亮的颜色。

氨基酸溶解在铁观音茶汤中，带给我们的感官体验是鲜爽度和甘甜。茶叶中含有多种不同的氨基酸，其中主要成分有茶氨酸，茶氨酸只存在于茶叶里，其他花草树木果蔬等都不含有茶氨酸。茶氨酸主要决定了茶叶的鲜爽度，另外也略带甜叶和苦味。大体上讲，氨基酸的含量越高，安溪铁观音茶汤的鲜爽度就越高。

茶多酚是铁观音茶叶当中的主要内含物，它是无色透明的，表现在茶汤的滋味上就是大家常说的“收敛性”。所谓收敛性指的是茶多酚于口腔粘膜蛋白质发生反应，会在口腔中生成一种不透水的新产物，新产物使口腔感到收敛感。茶多酚主要影响茶汤的浓度和收敛性，茶多酚含量越多，茶汤浓度越高，收敛性越强。

铁观音茶叶中也含有大量的咖啡碱。俗话说“不苦不涩不成茶”，茶汤中的苦涩物质就是咖啡碱。咖啡碱具有遇热则挥发的特性，因此随着茶叶冲泡次数的增多，茶汤中的咖啡碱会越来越少，苦涩味也会越来越不明显。

铁观音茶叶中的糖类物质体现在滋味上当然是对应着甜。糖类是我们熟悉的物质，甜味也是我们天生就喜欢的味道，人生下来品到的第一口味道就是甜。甜味是人类最好的安慰剂。

铁观音茶汤中的果胶可以给人带来饱满、醇厚和顺滑的口感。

铁观音茶叶中含有多种的芳香物质，芳香物质多具有挥发性，多不溶于水。体现在嗅觉上有玫瑰香、微苹果香、微乳香等等。

There are various substances in tea, and more than 140 kinds of substances have been counted. In general, the main contents of tea are tea polyphenols, amino acids, caffeine, carbohydrates, proteins, pectin, aromatic substances, chlorophyll, etc. The quality characteristics of tea are the external manifestation of these contained substances.

Among them, chlorophyll, lutein, lutein and other substances determine the color of tea leaves. The original substances of tea leaves in green tea are the most comprehensive and contain a large amount of chlorophyll. Therefore, green tea presents the quality characteristics of clear soup and green leaves. The tea polyphenols in black tea undergo an enzymatic oxidation reaction to generate lutein and lutein. Lutein is more dissolved in the tea soup, so the tea soup of black tea is golden yellow. Dark tea generally contains more lutein, so the tea soup of dark tea is mostly red and bright in color.

Amino acids are dissolved in the tea soup, giving us a sensory experience of freshness and sweetness. Tea contains a variety of different amino acids, the main component of which is theanine, which only exists in tea leaves, and other flowers, trees, fruits and vegetables do not contain theanine. Theanine mainly determines the freshness of tea leaves, and also has a slightly sweet and bitter taste. Generally speaking, the higher the amino acid content, the higher the freshness of the tea soup.

Tea polyphenols are the main contents in tea leaves, which are colorless and transparent, and are often referred to as "astringency" in the taste of tea soup. The so-called astringency refers to the reaction of tea polyphenols with oral mucosal proteins, which will generate a new impermeable product in the oral cavity, and the new product will make the oral cavity feel astringent. Tea polyphenols mainly affect the concentration and astringency of tea soup. The more tea polyphenols content, the higher the concentration of tea soup and the stronger the astringency.

Tea leaves also contain a lot of caffeine. As the saying goes, "no bitterness or astringency makes tea", and the bitter substance in tea soup is caffeine. Caffeine has the property of volatilizing when heated, so as the number of times of tea brewing increases, the amount of caffeine in the tea soup will become less and less, and the bitterness will become less and less obvious.

The sugars in tea are of course corresponding to sweetness in terms of taste. Sugar is a substance we are familiar with, and sweetness is also a taste that we are born with. The first taste of life is sweet. Sweetness is the best placebo for humans.

The pectin in the tea soup can give people a full, mellow and smooth taste.

Tea contains a variety of aromatic substances, most of which are volatile and insoluble in water. Reflected in the sense of smell, there are rose fragrance, micro apple fragrance, micro frankincense and so on.