Submitted to: Pittsburgh Conference
Publication Type: Abstract Only
Publication Acceptance Date: March 17, 2006
Publication Date: March 17, 2006
Citation: Taylor, S.L., Eller, F.J., Jackson, M.A., Stevenson, D.G. 2006. Pressurized fluid extraction of pumpkin seed and pumpkin seed pressed cake [abstract]. Pittsburgh Conference. p. 1220-5 Technical Abstract: Pumpkin seed oil is one of the top three nutritional oils (hemp seed oil, flax seed oil, pumpkin seed oil) that provide the highest essential fatty acids (Omega 3 and Omega 6) required for healthy mind/body functioning. It is known to prevent and alleviate bladder and prostate problems. The oil that is pressed from pumpkin seeds is of a deep reddish-green color and has a unique flavor. Twelve varieties of pumpkin seeds were extracted using supercritical fluid extraction (SFE) and accelerated solvent extraction (ASEtm). The extracts were gravimetrically analyzed for oil content. SFE was performed with neat carbon dioxide (CO2) at 100 degree C and 8500 psi, and ASEtm was conducted with hexane at 100 degree C and 1500 psi. Analyzing the data by a paired t-test, the ASEtm results were consistently lower than the SFE results. The overall mean for the accelerated solvent extractions was 19.91% compared to 20.62% for the SFE results. Four additional varieties were extracted by SFE and all four yielded higher oil recoveries, ranging from 34.1-44.5 wt%. One of these varieties, Retzer Gold, was chosen for process-scale extraction. The first quantity of pumpkin seed oil was produced by mechanically expelling the seeds. The oil remaining in the pressed cake was then extracted by SFE in a home built pilot-scale extractor. The pressed cake was ground in a Romer mill and then 2000 g were put in each of three 4-liter extraction cells. SFE was performed at 10,000 psi and 80 degree C with neat CO2. Once the cells were at pressure and temperature, CO2 (50 lbs) was recycled through the extractors in a parallel mode with a top to bottom flow pattern at a flow rate of ~0.6 lbs/min. An average of 13.1 wt% oil was recovered from the pressed cake.