普洱茶中氨基酸与贮期、级别及品质关系的研究

以不同储藏时期、不同级别的普洱茶为材料,对氨基酸总量及组分含量进行理化分析.结果表明,普洱茶贮藏过程中随着贮藏时间的加长,普洱茶中游离氨基酸总量明显降低,其中丝氨酸、甘氨酸、丙氨酸、异亮氨酸、亮氨酸、组氨酸已基本消减,仅检出精氨酸、脯氨酸、赖氨酸、苯丙氨酸、酪氨酸、缬氨酸、胱氨酸,其含量变化无明显规律性；从7个级别标准样中检出15种氨基酸,未检出苏氨酸、组氨酸、色氨酸,其中氨基酸含量最高的组分是精氨酸,其次是天冬氨酸、赖氨酸、苯丙氨酸、酪氨酸、谷氨酸.茶氨酸在普洱茶中的含量与其它茶类不同,其含量仅占普洱茶中游离氨基酸总量的30％左右.与其它茶类中氨基酸含量相比,普洱茶具有氨基酸种类齐全,营养配比全面、均衡的特点,在保健方面有特殊的意义.

Study on Relationship between Amino Acid and Storage Period,Grade,Quality of Pu-erh Tea

The content of amino acid and its’ components of Pu-erh tea from different areas,different processing stages and storage period was analyzed with Hydrated Ninhydrin-colorimetry.The results showed that(i) the total amount of free amino acids in Pu-erh tea was decreased significantly with the storage process.Serine,glycine,alanine,isoleucine,ammonia-acid and histidine were basically abated,only arginine,proline,lysine,phenylalanine,tyrosine,valine and cystine were detected,and there was no significant changes in its laws;(ii) Fifteen kinds of amino acids was tested from different levels Pu-erh,threonine,histidine and ryptophan were not found.Among them,the amount of arginine was the highest,and was followed by aspartic acid,lysine,phenylalanine,tyrosine,glutamate;(iii)Theanine in Pu-erh tea was different from that in other tea,and its’ content only was about 30 % of the free amino acids content in Pu-erh tea;(ⅳ)Compared with other tea,Pu-erh tea had all kinds of amino acid,balanced nutrition and played a significant role in healthy benefits.