EXTRACTION OF OIL FROM GRAPE SEEDS WITH SUPERCRITICAL CARBON DIOXIDE
INTRODUCTION Grape seeds are known as a waste byproduct of juice and wine production. They contain oil between 10 and 20%, depending on grape variety, which has high amounts of unsaturated fatty acids, usually linoleic and oleic acids ranged from 53 to 78% and 16 to 31% (Bail et al., 2008; Sabir et al., 2012). Oil from grape seeds is also constituted with natural antioxidants, among others, tocopherols in the 50 to 520 mg/kg range that are responsible for health-benefits such as lowering cholesterol levels and alleviating cardiovascular diseases (Bail et al., 2008; Sabir et al., 2012). Grape seed oil is a promising lipid for human consumption due to its nutritional constituents. The use of supercritical carbon dioxide (SC-CO2) is an effective method for oil extraction. It produces purer oil and preserves bioactive components of the oil when compared with the typical hexane extraction and refining. This is because the low critical point (Pc = 7.3 MPa, Tc = 31°C) and characteristics of CO2 that allows for organic solvent free extraction, making it safe and efficient for separation and fractionation of thermally sensitive oils (Agostini et al., 2012). In the present study the effects of pressure (20, 30 MPa) and temperature (30 °C, 40 °C, 50 °C) were investigated on the oil yield. The quality of SC-CO2 extracted oil in term of fatty acid content was compared to that of hexane-extracted oil.
Supercritical Extraction from Vinification Residues: Fatty Acids, α-Tocopherol, and Phenolic Compounds in the Oil Seeds from Different Varieties of Grape
Supercritical fluid extraction has been widely employed in the extraction of high purity substances. In this study, we used the technology to obtain oil from seeds from a variety of grapes, from vinification residues generated in the Southern region of the state of Rio Grande do Sul, Brazil. This work encompasses three varieties of Vitis vinifera (Moscato Giallo, Merlot, and Cabernet Sauvignon) and two of Vitis labrusca (Bordô e Isabel), harvested in 2005 and 2006. We obtained the highest oil content from Bordô (15.40%) in 2005 and from Merlot (14.66%), 2006. The biggest concentration of palmitic, stearic, and linoleic acids was observed in Bordô, 2005, and in Bordô, Merlot, and Moscato Giallo, 2006. Bordô showed the highest concentration of oleic acid and α-tocopherol in both seasons too. For the equivalent of procyanidins, we did not notice significant difference among the varieties from the 2005 harvest. In 2006, both varieties Isabel and Cabernet Sauvignon showed a value slightly lower than the other varieties. The concentration of total phenolics was higher in Bordô and Cabernet Sauvignon. The presence of these substances is related to several important pharmacological properties and might be an alternative to conventional processes to obtain these bioactives.
Industrial inorganic pigments
General Chemical and Physical Properties Behavior of Pigments in Binders White Pigments Titanium Dioxide Zinc Sulfide Colored Pigments Oxides and Hydroxides Cadmium Pigments Bismuth Pigments Ultramarine Pigments Iron Blue Pigments Carbon Black Properties Production Processes Specialty Pigments Magnetic Pigments Anticorrosive Pigments Luster Pigments Transparent Pigments.