Celebration of Scholars
Analysis of catechin and methylxanthine composition in tea (Camellia sinensis) by High-Performance Liquid Chromatography
Name:
Sean Hughes
Major: Biology
Hometown: Burbank, Illinois
Faculty Sponsor:
Other Sponsors:
Type of research: Independent research
Funding: Carthage Research Grant
Name:
Gunnar Goetz
Major: Biology
Hometown: Stoughton, Wisconsin
Faculty Sponsor:
Other Sponsors:
Type of research: Independent research
Funding: Carthage Research Grant
Name:
Renee' Jalbert
Major: Biology
Hometown: Belvidere, Illinois
Faculty Sponsor:
Other Sponsors:
Type of research: Independent research
Funding: Carthage Research Grant
Name:
Sarah Schmidt
Major: Biology
Hometown: Darwin, Minnesota
Faculty Sponsor:
Other Sponsors:
Type of research: Independent research
Funding: Carthage Research Grant
Abstract
Tea, a drink prepared from the leaves of Camellia sinensis, is considered to have both health benefits and risks relating to the presence of compounds such as catechins and methylxanthines, constituents that can vary according to processing technique. White tea, green tea, oolong tea, black tea, and puer tea are all made from the same leaf type, but are manufactured with varying degrees of fermentation (oxidation). In this study, we sought to characterize the phenolic content across tea processing methods. We also examined the levels of methylxanthine alkaloids, a class of psychoactive compounds.
We measured concentrations of the polyphenolic compounds catechin, epicatechin, epigallocatechin, epicatechin gallate, and theaflavin, by High-Performance Liquid Chromatography (HPLC). These compounds are antioxidants which could aid in neutralizing free radicals formed by cell processes. The less-fermented teas, such as green tea, were expected to have a greater proportion of catechins relative to the more complex, oxidized polyphenols including theaflavins and thearubigins that would be more abundant in oolong and black teas. We also quantified the methylxanthines theobromine, theophylline, and caffeine. While catechins vary depending on processing method, methylxanthines are expected to be consistent across tea types.
Preliminary data showed highly variable levels of catechins across processing methods, but the total phenolic content was found to be highest in green tea. In ongoing work, we are measuring levels of the individual catechins, theaflavins, and methylxanthines across several samples from each of the five tea types prepared using a standardized brewing protocol.