Effect of pH, Temperature, and Time on Inactivation of Tannins and Possible Implications in Detannification Studies

The tannins from quebracho and leaves of Acioa barteri after purification, and commercially available tannic acid, were stored in buffers of different pH values (6−11) at 0, 20, and 37 °C. The recovery of tannins was monitored at different time intervals (up to 18 h) using Folin−Ciocalteu and butanol−HCl−Fe3+ reagents. The recovery of tannins decreased with increase in time of storage, increase in pH, and increase in temperature. The decrease in...