Classification and Comparative Analysis of 22 Xinyang Maojian Teas with Various Origins

To find out the impacts of picked-processing duration, production place and grade on quality components in Xinyang Maojian tea, contents of catechins, flavonoids, phenolic acids and purine alkaloids in 22 Xinyang Maojian teas with various origins were determined by HPLC. PCA, HCA and PLS-DA confirmed that picked-processing duration was the main influence factor of quality components in teas, and various Xinyang Maojian teas were divided into Mingqian, Yuqian and Chunwei basically based on the picked-processing duration. One-way analysis of variance showed the highly significant differences (P<0.01) of 8 catechins, 5 flavonoids, 2 purine alkaloids, gallic acid and free amino acids among three picked-processing duration. Mingqian tea had highest contents of total free amino acids and (+)-catechin (C), but the lowest contents of GC, EGC, ECG, EGCG, gallic acid, rutin, myricetin, quercetin and theobromine, which showed the significant (P<0.05) or highly significant differences (P<0.01) compared with Yuqian and Chunwei. The significant (P<0.05) or highly significant differences (P<0.01) of catechins (i.e. C, ECG, EGC), flavonoids (i.e. rutin, taxifolin and myricetin), and theobromine and theophylline were found in Xinyang Maojian tea between different production place and grades. Relatively speaking, Maojian tea produced in Siwang hill had relatively higher content of non-ester catechins and lower total content of flavonoids, while Maojian tea of bud head grade had the highest contents of free amino acids and C, and lowest contents of EGC and myricetin, which had certain impact on the identification of picked-processing duration. This study was the first time to classify and compare Xinyang Maojian teas from various origins based on the quality components in tea, which provided the scientific evidences for the identification of Mingqian tea.