Caffeine in Tea

Caffeine, present among flavor compounds in tea, is antimycotic as well as antibacterial. Inhibition of growth of several mycotoxigenic Aspergillus and penicillium spp at concentrations as low as 1microgram ml has been documented. Production of aflatoxin A, sterigmatocystin, citrinin and patulin by moulds is adversely affected by caffeine. 

The mode of action of caffeine on metabolic functions of fungal cells has not been clearly defined. There was reported that caffeine, but not theophylline or papaverine, uncoupled the regulation of glycolysis and glucogenesis. 

Inhibition of growth of A.parasiticus by caffeine is due in part to an alteration in purine metabolism, but inhibition of aflatoxin synthesis does not apparently involve an inhibition of cyclic adenosine monophosphate (AMP) phosphodiesterase or a chelation of key metal ion. 

Evidence does suggest that caffeine may restrict glucose uptake by A.parasiticus, resulting in decreased aflatoxin production. A preliminary examination of the affect of caffeine on patulin production by penicillium suggests that activity does not involve a generalized inhibition of lipid synthesis.

Caffeine in Tea