Extraction behaviors of caffeine and chlorophylls in supercritical decaffeination of green tea leaves精品.pdfVIP

LWT - Food Science and Technology 45 (2012) 73e78 Contents lists available at ScienceDirect LWT - Food Science and Technology journal homepage: www.els /locate/lwt Extraction behaviors of caffeine and chlorophylls in supercritical decaffeination of green tea leaves Hyong Seok Park, Nam Gyu Im, Kyoung Heon Kim* School of Life Sciences and Biotechnology, Korea University, Seoul 136-71, Republic of Korea a r t i c l e i n f o a b s t r a c t Article history: The decaffeination of green tea using supercritical carbon dioxide (SC-CO2) was optimized by response Received 8 December 2010 surface methodology (RSM) for the maximal removal of caffeine, and the coextration of chlorophylls was Received in revised form also monitored during decaffeination. The experimental conditions for the SC-CO2 extraction of caffeine 6 July 2011 were set up according to the Box-Behnken design of RSM. The relationships between the extraction yield Accepted 15 July 2011 of caffeine and various parameters used for the SC-CO2 extraction such as pressure, temperature and concentration of ethanol were studied at a fixed CO2 flow rate. The extraction yields of caffeine and total Keywords: chlorophyll were significantly influenced by extraction pressure, temperature and concentration of Supercritical carbon dioxide Green tea cosolvent, and their e