Studies on the extraction of Pinus brutia bark using the Gulbaran extractor-diffuser

Abstract

In this study, extraction of Pinus brutia bark is performed using a new extractor-diffuser system. This new extraction system uses a moving bed of bark which is continuously washed with fresh solvent sprayed from mobile spray nozzles. To confirm the performance of the Guelbaran extractor for extraction of P. brutia bark, the effects of extraction temperature, residence time, solvent/raw material ratio and particle size on the tannin yield were investigated. The bark used in this study was obtained from Kuetahya/Aegean region of Turkey. The average tannin content of the bark was determined to be 19.64% on a dry basis. The experiments performed showed that the optimum extraction conditions are 180 min. extraction time, 0,65-0,75 mm particle size, 6 kg solvent/kg raw material ratio and 95°C solvent temperature. In the batch experiments the bark of P. brutia leached in hot water yielded 94.56% of the tannin. The resultant extract in this system was more dilute than that produced by some multicell extractors, thus requiring more evaporator costs.