ON MANGANESE-INDUCED REDDENING OF FLORETS FROM DYERS SAFFRON CAPITULA

The effect of external conditions on permanganate-mediated carthamin formation was studied in floret suspensions under various experimental conditions. The reaction proceeded readily in acidic media (pH 3.4), where carthamin exhibits a stable red coloration. Temperature affected the reaction greatly: the red coloration in florets developed effectively at a lower temperature range (0 +/- 1-degree-C) rather than at a higher one (80 +/- 1-degree-C), showing that it follows first-order reaction kinetics. Antioxidants and metal chelators variously affected the permanganate catalysis. Attempts to promote the metal-induced floret reddening were found to be of little use.