Purine Alkaloid Production And Accumulation In Cocoa Callus And Suspension-Cultures

Cocoa callus and suspension cultures were found to produce caffeine, theobromine, and theophylline which are typical of the purine alkaloids found in cocoa beans. Production of these purine alkaloids was monitored in callus cultures for over 2 years and shown to stabilize at concentrations of about 10% those found in vivo. Caffeine and theobromine were produced concomitant with log phase growth of the cultures whilst theophylline production reached a maximum during stationary phase, reflecting the possible role of the latter as a catabolite of caffeine. The effects of choice of cytokinin, explant tissue, cocoa type, light conditions and time in culture on purine alkaloid production by callus have been examined. Purine alkaloid production by cocoa suspension cultures has also been examined and these cultures were shown to be less productive and more variable than callus cultures. The results demonstrate that cocoa tissue cultures can be useful for studying secondary metabolism in vitro.