Comparative Analysis of Purine Alkaloids and Main Quality Components of the Three Species in China.

Tea () is a widely consumed caffeine-containing beverage, however the genus also includes other species, which are consumed as tea in their local growing regions. Presently, HPLC analysis assessed 126 unique germplasms belonging to three species, (), () and (). Theobromine was the predominant purine alkaloid in all species, representing over 90% of purine alkaloids in and , and 50% in . Significant variability existed in purine alkaloid patterns both between and within species, and some germplasms possessed highly unique alkaloid profiles. Sensory evaluation and quality composition analysis of green tea products produced from the three species suggested their unsuitability for use in tea production due to their unpalatable flavor. The results of this study revealed the differences in purine alkaloids and main quality components between species and tea, which contributed to understand why tea, rather than other species, has become a popular beverage in the world after long-term artificial selection. In addition, unique alkaloid profiles suggest usefulness of these germplasm resources in future breeding of decaffeinated tea plant varieties and alkaloid metabolism research.