Designing supercritical carbon dioxide extraction of rice bran oil that contain oryzanols using response surface methodology

Abstract

This study examines the supercritical carbon dioxide (SC-CO(2)) extraction of oryzanols contained rice bran oil from powdered rice bran. The extraction efficiencies and concentration factors of oryzanols, free fatty acids and triglycerides in the SC-CO(2) extracts were determined. With top-flow type SC-CO(2) extraction the total oil yield was 18.1% and the extraction efficiencies of oryzanols and triglycerides were 88.5 and 91.3% respectively, when 2750 g CO(2 )was consumed during the extraction of 35 g rice bran powder. The concentration factors of oryzanols and triglycerides in SC-CO(2)-extracted oil were higher than in the Soxhlet n-hexane extracted oil. SC-CO(2) extractions indicated that pressure can be used more effectively than temperature to enhance the extraction efficiency and concentration factor of oryzanols. A two-factor central composite scheme of response surface methodology was employed to determine the optimal pressure (300 bar) and temperature (313 K) for increasing the concentration of oryzanols in the SC-CO(2) extracted oil.

Supercritical CO₂ Extraction of Rice Bran Oil –the Technology, Manufacture, and Applications

“…At lower pressure, the density of SC-CO 2 is considerably decreased, which causes lower diffusion of SC-CO 2 into RBO 36 . Considering as an alternative to the conventional solvent extraction method of RBO, RBO derived from SC-CO 2 extraction testing range of 40-80 and 15-25 MPa contained fatty acid profile consisting of oleic acid 39-51 , linoleic acid 28-38 , and palmitic acid [20][21][22] , which was comparable to RBO derived from compressed liquefied petroleum gas extraction having oleic acid [35][36][37][38][39][40][41][42][43][44][45][46][47][48] , linoleic acid 30-44 , and palmitic acid 19-22 37 . The study by Kuk and Dowd 32 used SC-CO 2 at 62 MPa and 100 to obtain a maximal oil yield of 20.4 .…”

“…This difference suggests that SC-CO 2 as a technology for production of a phytosterol-enriched vegetable-oil extract 40 . A study by Wang et al 41 employing SC-CO 2 extraction as a technology for preparing γ-oryzanols from powdered rice bran reported that total RBO yield was 18.1 and the extraction efficiencies of γ-oryzanols and triglycerides were 88.5 and 91.3 respectively. The concentration of γ-oryzanols and triglycerides in SC-CO 2 -extracted RBO was higher than that in Soxhlet-hexane extracted oil 41 .…”

“…For applications, a number of researchers have employed RSM and CCD methodology on SC-CO 2 extraction of RBO. It has been used for supercritical extraction of RBO with high γ-oryzanol content 14,41 . Operation parameters were optimized for the highest oil recovery 47 , for oil with highest antioxidants 44 , and for the best operation processes of RBO deacidfication 39 .…”

Extração Supercrítica Do Óleo De Farelo De Arroz

“…O RBO contém 95,6% de lipídios saponificáveis, incluindo glicolipídios e fosfolipídios, e 4,2% de lipídios insaponificáveis, incluindo tocoferóis, tocotrienóis, oryzanóis, esteróis e carotenóides (Chen et al, 2008). Os compostos bioativos encontrados no RBO (γ-orizanol, tocotrienóis e tocoferóis) têm alto poder de ação antioxidadante e têm demonstrado várias atividades benéficas à saúde, como a redução dos níveis de colesterol (Ismail et al, 2010).…”

“…A SFE é considerada ideal para extração e fracionamento de óleos e uma alternativa ambientalmente segura quando comparada à extração convencional, além de apresentar vantagens como o aumento da seletividade e da automaticidade, e resultar em extratos livres de resíduos de solventes, tornando a qualidade do óleo superior ao extraído pelo método convencional (Wang et al, 2008;Ismail et al, 2010;Roseiro et al, 2013). O CO 2 é o solvente mais utilizado na SFE do óleo de farelo de arroz, visto que é não tóxico, não inflamável, não corrosivo e está disponível a baixo custo com alto grau de pureza (Ismail et al, 2010;Roseiro et al, 2013).…”