Publications by authors named "Miho Hiwatashi-Kanno"
Theaflavin, a polyphenol responsible for the bright orange color and various bioactivities of black tea exudates, is susceptible to autoxidation at neutral and mild alkaline pH, changing its color to brown. In the presence of cysteine (Cys), glutathione (GSH), or N-acetyl cysteine (NAC), the browning of theaflavin solution was inhibited concomitantly with time-dependent decreases in the concentrations of both theaflavin and thiol group. The rank order of the decrease was Cys ≅ GSH > NAC, suggesting the relevance of the nucleophilic property of the thiol group to its reaction with theaflavin.
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