44E-12

B. BOZAN, Medicinal & Aromatic Plant & Drug Research Centre (TBAM), Anadolu Univ., Eskisehir, 26470, Turkey and F. Temelli, Dept. of Agricultural, Food & Nutritional Science, Univ. of Alberta, Edmonton, AB T6G 2P5.

Flaxseed is one of the economically important oil seed crops in the world market. Since flaxseed is rich in a-linolenic acid (C18:3), fiber components and phytochemicals such as lignans, it has received great interest from the food and nutraceutical industries in recent years. The physiological benefits of flax oil are attributed primarily to the high a-linolenic acid (ALA) content. Solvent extraction is commonly used to extract lipids from oil seed. However, polyunsaturated fatty acids may be subjected to thermal degradation under the conditions of conventional solvent extraction. Recently, the extraction of specialty oils from various plant materials with supercritical fluids received increasing attention to eliminate the use of organic solvents.

The objectives of this study were: a) to extract flaxseed oil using supercritical carbon dioxide (SC-CO₂) at different conditions and compare to solvent extraction, and b) to perform chemical analysis of extracted oils to determine fatty acid composition and tocol (tocopherols and tocotrienols) content.

Extraction of oils with SC-CO₂ was conducted at temperatures of 50^oC and 70^oC pressures of 35.96 MPa and 57.53 MPa and CO₂ flow rates of 1L/min and 3L/min for 3h. Solvent extraction was performed with petroleum ether using soxhlet apparatus. Fatty acid composition and tocol content of the extracted oils were determined by GC and HPLC, respectively.

Higher solubility of oil was observed at 70^oC/57.53 MPa/1L/min as 20.49 mg/L CO₂. After 3h extraction, oil yield obtained at 70^oC/35.96 MPa/1L/min CO₂ reached 87.6% of yield obtained with soxhlet extraction. While a-linolenic acid content of SC-CO₂ extracted oils was 60.0-60.5%, it was only 56.7% in oil obtained by Soxhlet extraction. Highest total tocol content was 0.88 mg/mg in the oil obtained at 50^oC/34.96 MPa/1L/min CO₂.

Flax oil can be extracted with SC-CO₂ with no concern of organic solvent residue and minimal degradation of sensitive components for nutraceutical purposes.

Session 44E, Nutraceuticals & Functional Foods
8:30 AM - 12:00 PM, 2001-06-25 Room Hall D

2001 IFT Annual Meeting - New Orleans, Louisiana