MUTAGENICITY OF GREEN, OOLONG, AND BLACK TEAS (FLAVONOID, QUERCETIN, KAEMPFEROL, MYRICETIN)
Abstract
Preliminary studies indicated that green, oolong, and black tea contained components that were shown to be mutagens by the Ames mutagenesis assay method. Salmonella typhimurium TA98 was used throughout as the test strain. Several techniques were used to extract and fractionate polyphenolic compounds for tea infusions. The most convenient procedure was to extract polyphenols with acidified 1-butanol and to precipitate them into an aqueous phase with petroleum ether. The resulting aqueous suspension was freeze dried and the polyphenols separated and identified. Identification of the isolated flavonoids causing mutagenic response in tea was done by HPTLC and GLC, and further confirmed by GC-Mass spectrometry. The major mutagens of green, oolong, and black tea were flavonol aglycones, quercetin, kaempferol, and myricetin. The same compounds were responsible for mutagenicity in green, oolong, and black tea, however, there were significant differences in concentration of active compounds. Green tea had considerably greater concentration of quercetin. This apparently contributes to the higher mutagenicity of green tea reported in the latter stage of investigation. Quercetin was the most potent of the three mutagens.
Degree
Ph.D.
Subject Area
Food science
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