Nanofiltration process for the nutritional enrichment and refining of rice bran oil

Crude rice bran is a natural source of gamma-oryzanol, a nutritionally valuable phytochemical with antioxidant properties In the present paper the refining and gamma-oryzanol enrichment of rice bran oil was investigated through solvent extraction optimization and nanofiltration processing Several solvent resistant nanofiltration membranes were screened and successfully applied in a two step membrane cascade with fluxes between 39 and 53 L m(-2) h(-1). A first membrane stage operation provided the separation between glycerides and gamma-oryzanol, promoting the oil enrichment in this phytochemical In the second membrane stage the oil could be refined to acceptable consumption levels (FFA < 020 wt %) and its gamma-oryzanol content was further enhanced. Overall, the integrated process provided a RBO gamma-oryzanol enrichment from 095 to 4 1 wt % in oil, which corresponded to more than a two fold increase in the oil's antioxidant capacity. These results demonstrate the potential of organic solvent nanofiltration as a technology to enrich and refine oil based products (C) 2010 Elsevier Ltd All rights reserved