Journal of Food Engineering, Vol.78, No.2, 488-493, 2007
Improving the extraction of alpha-tocopherol-enriched oil from grape seeds by supercritical CO2. Optimisation of the extraction conditions
In this work milled grape seeds from Vitis Vinifera were leached with supercritical carbon dioxide (SC-CO2) to assess the opportunity to obtain and a-tocopherol-enriched oil, having many potential uses in both the pharmaceutical and food industry. The extractions were carried out at the pressure of 25 MPa without pre-soaking to better reflect the prospective operation mode in a forthcoming industrial use.The obtained results were evaluated in terms of total amount of oil and total amount of alpha-tocopherol extracted from milled grape seeds as a function of particle size, extraction temperature and CO2 to seed mass ratio. The optimal extraction conditions were found to be 80 degrees C and ground seed fragment size in the range 300-425 mu m; under these conditions the extracted oil contains as much as 265 ppm alpha-tocopherol. All the obtained results were compared to those of n-hexane extraction: the alpha-tocopherol concentration in the oil extracted with SC-CO2 is higher than that obtained by n-hexane, while the overall oil yield is lower. (c) 2005 Elsevier Ltd. All rights reserved.