The supercritical carbon dioxide (SC-CO2) extraction technique has emerged as one of the best possible alternatives to organic solvent (hexane) extraction. However, very limited information is available on process optimization for this extraction technique and the lack of available engineering data is causing the slow growth of this technique. In the present investigation, SC-CO2 extraction was carried out to extract the oil from wheat germ under various operating conditions and the oil samples were characterized for properties such as phosphorous and tocol contents (vitamin E). A three-level Box Behnken design from response surface methodology was applied to optimize the SC-CO2 extraction parameters such as pressure, temperature and CO2 flow rate with an objective to obtain high oil yield, rich tocol contents and low phosphorous content. The process parameters were maintained between 30 to 50 MPa, 40 to 60 °C and a flow rate of 10 to 30 g·min-1 in a Box Behnken design matrix. Three different second order polynomial models were obtained for oil yield, phosphorous content and tocol contents with high R2 values. The optimum conditions were found to be 50 M Pa, 60 °C and 30 g·min-1 where the predicted oil yield, phosphorous content and tocol contents were found to be 8.87%, 31.86 mg·Kg-1 and 2059.92 mg·Kg-1 respectively. Under the optimum conditions, the experimental oil yield, phosphorous content and tocol contents obtained were found to be very close to the values predicted by the model.

SUMMARY:In the present study, the supercritical carbon dioxide (CO 2 ) extraction of oil from Simarouba gluaca seeds was carried out at varying conditions of pressure (300-500 bar), temperature (50-70 °C) and CO 2 flow rate (10-30 g·min -1 ). The extraction condition for maximum oil yield was obtained at 500 bar pressure, 70 °C and at 30 g·min -1 flow rate of CO 2 . The extracted oil was analyzed thoroughly for physico-chemical properties and compared with those of conventional solvent extracted oil. An interesting observation is a significant reduction in the phosphorus content of the oil (8.4 mg·kg -1 ) extracted using supercritical CO 2 compared to the phosphorous content of the solvent extracted oil (97 mg·kg -1 ). Moreover, the content of total tocopherols in supercritically extracted oil (135.6 mg·kg RESUMEN: Estudio comparativo de la extracción con solvente y CO 2 supercrítico de aceites de semillas de Simarouba glauca. En el presente estudio se llevó a cabo la extracción con dióxido de carbono supercrítico (CO 2 ) de aceites de semillas de Simarouba gluaca en diversas condiciones de presión (300-500 bar), temperatura (50-70 °C) y el caudal de CO 2 (10-30 g·min -1 ). La condición de extracción para obtener el máximo rendimiento de aceite se obtuvo a una presión de 500 bares, una temperatura de 70 °C y un caudal de CO 2 de 30 g·min -1 . Al aceite extraido se determinó sus propiedades fisicoquímicas y se comparó con las del aceite extraído con disolvente convencional. Una observación interesante es la reducción significativa del contenido de fósforo (8,4 mg·kg -1 ) del aceite extraído utilizando CO 2 supercrítico en comparación con el del aceite extraído con disolvente (97 mg·kg -1 ). Además, el contenido de tocoferol total en el aceite extraído supercríticamente (135,6 mg·kg -1 ) fué más elevado que el extracto con disolvente (111 mg·kg -1 ). El resto de las propiedades físico-químicas de dos aceites extraídos de forma diferente se equipararon entre sí. Los resultados indicaron los posibles beneficios de la extracción con CO 2 supercrítico sobre la extracción con disolvente del aceite de semilla Simarouba gluaca.