Three-phase partitioning (TPP) is a novel separation process used for the extraction and purification of biomolecules. The biomolecules are recovered in a purified form at the interface (precipitate), while the contaminants partition in t-butanol and aqueous phases. Peroxidase from the leaves of Ipomoea palmata was purified by using TPP. The ratio of the crude extract to t-butanol of 1:1 and 30% ammonium sulfate at 37 degrees C resulted in about 160% activity recovery and twofold purification in the aqueous phase of the first cycle of TPP. On subjecting the aqueous phase to the second cycle of TPP, a purification of 18-fold was achieved with about 81% activity recovery. The sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis showed substantial purification, and the molecular weight of peroxidase was found to be 20.1 KDa. The present study shows a higher degree of purification and activity yield as a primary purification process in comparison with existing literature values, thus demonstrating TPP as an attractive downstream process for the purification of peroxidase.

Oryzanol is an important value-added co-product of the rice and rice bran-refining processes. The beneficial effects of oryzanol on human health have generated global interest in developing facile methods for its separation from rice bran oil soapstock, a by-product of the chemical refining of rice bran oil. In this article we discuss the isolation of oryzanol and the effect that impurities have on its extraction and purification. Presented are the principles behind the extraction (solid-liquid or liquid-liquid extraction, and other methods) of these unit operations covered in selected patents. Methods other than extraction such as crystallization or precipitation-based or a combination of these unit operations also are reviewed. The problems encountered and the ways to solve them during oryzanol extraction, such as prior processing and compositional variation in soapstock, resistance to mass transfer, moisture content and the presence of surface active components, which cause emulsion formation, are examined. Engineering inputs required for solving problems such as saponification, increasing mass transfer area, and drying methods are emphasized. Based on an analysis of existing processes, those having potential to work in large-scale extraction processes are presented.Rice is the second-largest cultivated crop produced worldwide with current annual world production being approximately 583 million metric tons (1). Rice bran is one of the valuable byproducts of the rice processing industry (2). In many instances, it is economically feasible to extract oil from rice bran and purify it by physical and chemical refining for either food or industrial use. Owing to several technical and nontechnical problems in oil refining, the actual annual production of rice bran oil (RBO) does not meet demand (3). The major difficulties in processing crude RBO for edible purposes are its high levels of FFA, waxes, gums, and pigments. Accordingly, most RBO is used in nonfood applications. Chemical refining of RBO produces soapstock by-product (RBOS). The typical soapstock from RBO contains ~65-70 wt% water, 20-22 wt% soap, 2-2.5 wt% glycerides (mainly TG), and 7-7.5 wt% unsaponified matter. The unsaponified fraction contains ~42% sterols, 24% higher fatty alcohols, 20% oryzanol (as ferulic acid esters), 10% hydrocarbons, and 2% unidentified compounds (4). Oryzanol represents ~15% (2% of 7.5 wt%) of the unsaponified matter. At present, the major use of the soapstock is the generation of soap for the toiletry and detergent industries. It could also be used for production of therapeutically active components such as oryzanol and tocopherols (5). In view of the amount of oryzanol present in RBOS, which is generated in large amounts, there is an opportunity for commercial production of oryzanol from this by-product.Chemically, oryzanol is a mixture of ferulic acid esters of triterpene alcohols (phytosterols), i.e., ferulate (4-hydroxy-3-methoxy cinnamic acid) (6). The components of oryzanol were identified as ∆ 7 -stigmastenyl ferulate, ...

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