Extraction of coriander oil by twin-screw extruder: Screw configuration and operating conditions effect

A new process, in which coriander fruits are pressed in a co-rotating twin-screw extruder, is examined here. Six tests were examined to define the best performance (oil extraction yield, and oil quality) by studying the influence of operating conditions, screw speed and flow rate. The screw speed and flow rate affected oil extraction yield. An increase of oil extraction yield was observed as the screw speed was increased (100 rpm) with a decreased flow rate of fruit (2.27 kg/g). Highest oil extraction yield was obtained under operating conditions of 50 rpm and 2.27 kg/h. Effect of the operating parameters on fatty acid composition was less important. Ten fatty acids were identified, with petroselinic acid accounting for 66-75%, followed by linoleic, oleic and palmitic acids, accounting for 13-19%, 5-7% and 4-5%, respectively, of the total fatty acids. beta-Sitosterol was the major sterol in all oils with 31% of total sterols. (C) 2012 Published by Elsevier B.V.