Ultrasonic technology and response surface methodology (RSM) wereused for optimization of extraction of condensed tannins from the leaf, acron, gland and gall of oak. Three independent variables such as solvent percentage (%), temperature (°C) and time (min) were studied. Effect of methanol concentration was found to be significant on all responses. Optimal ultrasonicassisted extraction (UAE) conditions were identified as 74–82% methanol, 60°C and45 min.The experimental values agreed with those predicted by RSM models, thus indicating suitability of the models employed and the success of RSM in optimizing the extraction conditions. Condensed tannins can be used as wood adhesives.
