Characteristic amino acids in tea leaves as quality indicator for evaluation of Wuyi Rock Tea in different cultured regions

Characteristic amino acids in Wuyi Rock Tea

  • Xiaoli Jia
  • Jianghua Ye
  • Haibin Wang
  • Li Li
  • Feiquan Wang
  • Qi Zhang
  • Jiebo Chen
  • Xinyu Zheng
  • Haibin He

Abstract

Free amino acid compositions in Wuyi Rock Tea leaves from Yu (authentic rock region), Guiyan (semi-authentic rock region) and Qishan (ordinary region) tea plantations were analyzed. Results showed that contents of 18 free amino acids were 1.6-2.0 times higher in Yu and Guiyan than that in Qishan. The theanine contents reached to 17-20 mg g-1 in Yu and Guiyan, while it was less than 10 mg g-1 in Qishan. Hierarchical cluster analysis and principal component analysis were effective in distinguishing Rock Tea from different regions. The ratios of theanine, sweet and umami amino acids were 8%, 5% and 6% higher, respectively in Yu than that in Qishan. Sensory evaluation score were positively correlated with the ratios of theanine, sweet and umami amino acids (P < 0.05 or P < 0.01). Our results highlight that the favourite characteristic amino acids are dominant contributors to sweet aftertaste of Rock Tea.

Published
2018-07-26