Title of Invention

"AN IMPROVED PROCESS FOR RECOVERY OF ORYZANOL"

Abstract

The present invention relates to an improved process for preparation of oryzanol. In particular the invention describes a process for preparation of pure oryzanol from wet soapstock of rice bran oil". The oryzanol concentrate produced is of food grade and can be used in any industry for application as a micronutrient in healtlh foods, pharmaceuticals and cosmetics forgetting lowering of cholesterol in the blood and for improvement of skin aging. In the present invention, the glycerides present in the oryzanol concentrate are removed by partitioning with hexane, the gums and wax are removed by precipitation with ketonic solvents and the free fatty acids are removed by treatment with alcohol thereby the purity and recovery of the final product has been improved to get 100% pure product.

Full Text

The present invention relates to an improved process for the recovery of oryzanol. In particular the invention describes a process for preparation of pure oryzanol from wet soapstock of rice bran oil" The oryzanol concentrate produced is of food grade and can be used in any industry. The oryzanol produced is of food grade and can be used in any industry for application as a micronutrient in healtlh foods, pharmaceuticals and cosmetics for getting lowering of cholesterol in the blood and for improvement of skin aging. The other beneficial effects of oryzanol are muscular toning for sports personnel, treatment of menopausal disorders in women and development of skin capillaries. Reference may be made to the work of Rao.B.V.S., Rao, K.V.S.A., and T.N.B.Kaimal (USpatent No.US6410762, (2002)] , wherein, the patent refers to the isolation of oryzanol from the soapstock of rice bran oil after saponification of glycerides present in the soapstock for periods varying from 0.5 to 4hours The soapstock so produced may also generate ferulic acid and sterols as the hydrolysis products and in addition, the oryzanols being alkali soluble also may get destroyed during saponification step producing low yields of the oryzanol concentrate with added impurities such as sterols, unsaponified phospholipids and waxes, and high molecular weight alcohols arising out of saponfication of wax which is present as an impurity in the soapstock requiring additional purification steps. Reference may also be made to another US patent by Kumar, DP., Kaimal, T.N.B., Bhalerao, U.T., and Chaudhuri, A.,[(USpatent No.US5869708, (1999)] wherein oryzanol is isolated from the residue obtained after distillation of the fatty acids of the acid oil of rice bran soapstock. The distillation of fatty acids are generally carried out at very high temperatures and low pressures and still the high temperatures may not be conducive for the stability of oryzanol and the destruction of oryzanol might take place. Also purification of oryzanol concentrate by column chromatography has been achieved which involves use of large amounts of solvents for complete elution of oryzanol from the column. There is a crystallization step using toxic solvents. Residue in the product may be harmful when used in foods. Reference may also be made to Indian Patent NO. 189742, wherein the extraction of oryzanol from wet soapstock has been done using solvent partition technique, the amount of purity obtained may range from 25-62% with 20-75% recovery and further purification has not been attempted. Also as the purity increases, the recovery of 75% at 25% purity goes down to 20% at 62% purity indicating that the recovery or the yield goes down with improvement of purity in the earlier process has also been addressed in the present invention. The main object of the present invention is to provide "A process for preparation of pure food grade oryzanol from wet soapstock of rice bran oil" which obviates the drawbacks as detailed above. Another object of the present invention is to provide other lower purity oryzanol concentrates in addition to pure oryzanol for application in food and pharmaceutical or cosmetic industries. Accordingly, the present invention provides "A process for preparation of pure food grade oryzanol from wet soapstock of rice bran oil" which comprises a)extracting the oryzanol containing soap-stock with a mixture of a non-polar hydrocarbon solvent and an water miscible polar solvent, b)separating the oryzanol into an alkali phase c)neutralizing and back extracting with a nonpolar organic solvent to get the oryzanol concentrate; which is then purified by d)solvent degumming using a ketonic solvent e)solvent deacidification using an aqueous aliphatic alcohol and then f)crystallizing from a non-polar aliphatic hydrocarbon solvent to get oryzanol of >95% purity. In an embodiment of the present invention, the back extracting alkali solution for oryzanol can be selected from inorganic bases of sodium or potassium elements. In another embodiment of the present invention, the acid solution for neutralization may be selected from hydrochloric, sulphuric or acetic acids of 0.1N to 10N solutions. In yet another embodiment of the present invention, the polar solvent can be selected from ethyl alcohol, methyl alcohol, propyl alcohol or a combination there of in the ratio of 1:1 to 1:20. In still yet another embodiment of the present invention, the degumming solvent for the separation of phospholipids and waxes from oryzanol may be selected from C3-C4 aliphatic ketonic solvents. In still yet another further embodiment of the present invention, the deacidification solvent used for removal of fatty acids from oryzanol can be selected from C1-C3 aliphatic alcohols. In still yet another still further embodiment of the present invention, the solvent used for crystallization of oryzanol may be selected from C5-C8 aliphatic hydrocarbon solvents. The present process consists of extracting oryzanol from wet soapstock by using hexane and ethyl alcohol the extracting solvent mixture by mixing mechanically at 225rpm for 5 minutes at room temperature(27°C) using ethanol as the deemulsifier followed by settling for 15 minutes to separate the supernatant hexane layer (which contains the extracted oryzanol), which is treated with aqueous potassium hydroxide solution to preferentially separate the oryzanol fraction and then acidified, extracted with hexane, washed with aqueous alcohol to free it from acid and then the hexane layer desolventized, and dried to get oryzanol concentrate. The oryzanol concentrate so obtained is purified by using solvent degumming, deacidification and crystallization procedures avoiding column chromatography which requires large volumes of solvent for elution. The solvent degumming, deacidification and crystallization procedures are carried out on the oryzanol concentrate by using ketonic solvent, alcohol and hydrocarbon solvents in succession to purify the oryzanol concentrate to 100% purity. The details of recovery and purity and characteristics of the product are given in Tables 1-3. The novelty in the present process is the improvement in the purity of oryzanol compared to the previously developed patented process on oryzanol extraction from wet soap stock of rice bran oil using solvent partition technique of Gopala Krishna & Sakina Khatoon, (Gopala Krishna, A.G., and Sakina Khatoon, Indian Patent No.4150/DEL/1998) wherein the extraction of oryzanol has been done using hexane and ethanol as solvents, the purity obtained may range from 25- 62% but the recovery of purified material in good yield is a problem due to the solubility of oryzanol in the glycerides and free fatty acids which are present as an impurity. In the present invention, the glycerides present in the oryzanol concentrate are removed by partitioning with hexane, the gums and wax are removed by precipitation with ketonic solvents and the free fatty acids are removed by treatment with alcohol thereby the purity and recovery of the final product has been improved to get 100% pure product but the recovery has also been slightly improved and there is scope for further improvement and production of food grade oryzanol on a large scale in India. A flow sheet is given which represents the steps involved in the process of oryzanol concentrate preparation and its purification. Soap-stock(wet) Hexane extract + soapstock solution (spent) I Oryzanol separation I Washing with water I Mixing with 70%alcohol and heating Hexane extract layer + Aqueous phase Desolventization Oryzanol concentrate + Recovered Hexane. Soapstock phase + Aqueous phase Acidification Distillation Fatty acids (By-product I) + Recovered ethyl alcohol and hexane Aqueous phase Dry in pond Potassium chloride recovery, (By-product II) Oryzanol concentrate Acetone extraction Desolventization Alcohol extraction(70%) Alcohol soluble fraction desolventization(alcohol and fatty acids recovery) Alcohol insoluble fraction Desolventization and drying Hexane addition and boil, cool and allow to crystallize 4 Filter I Oryzanol crystals(95%pure) + Filtrate Desolventize filtrate Oryzanol concentrate(50% purity) + Recovered Hexane Solvents are receovered in separate steps. The following examples are given by way of illustration of the present invention and therefore should not be constructed to limit the scope of the present invention. Example-1 a) Extraction of oryzanol from soapstock and preparation of oryzanol concentrate: To Skilograms of soap-stock(70%moisture) was added 7.5litres of ethyl alcohol(rectified spirit) and 75litres of hexane(food grade)mixed mechanically at 225rpm for 15 minutes at room temperature(27°C), allowed to settle for 15 minutes. Afterwards, the supernatant hexane layer(H1) was retained in the vessel by carefully draining off the bottom alcoholic phase(mother liquor- Mi) and collecting separately. To the hexane phase(H1) is now added 2.5litres of potassium hydroxide(IN) and mixed mechanically at 175rpm for 15 minutes and then allowed to settle for 15 minutes. The bottom aqueous potassium hydroxide layer(K1) was collected separately in another container. The supernatant hexane layer (H2) is treated with 50millilitres of hydrochloric acid(1N) and then the hexane layer is reused for repeatedly extracting the mother liquor (M1) layer three more times as indicated above. The potassium hydroxide layers(K1-K4) pooled and neutralized with hydrochloric acid(1N) to a pH of 4.0 and then the layer extracted with 2.5litres of hexane thrice and the hexane phase pooled, treated with 2.5litres of rectified spirit(ethyl alcohol) and 1.25litres of tap water and mixed mechanically at 80°C, for 15 minutes, and the hot alcoholic phase drained off and desolventized to recover alcohol. The hexane phase is now desolventized and dried to get oryzanol concentrate and hexane is recovered. The oryzanol content and recovery values are given in Table 1. b) Extraction of fatty acids from spent soapstock solution: The spent soapstock is acidified and desolventized to get residual amounts of hexane and ethyl alcohol is also recovered and fatty acids are obtained as the residue. The recovery of the solvent was 75% and the oryzanol was 29.4% with a purity of 50%. The fatty acid fraction formed 30% of the raw material. The bulk of the hexane phase can be reused for extraction purposes and therefore distillation of solvent in terms of quantity will be only 15-20% of the starting solvent volume and hence saving in solvent evaporation and solvent loss costs. c) Purification of oryzanol concentrate to get pure food grade orvzanol: To 10grams of oryzanol concentrate was added lOOmillilitres of acetone, heated gently to dissolve all the oryzanol into the solvent by keeping on the hot water bath at 75°C for 15 minutes, cooled under tap water and allowed to settle for 15 minutes at room temperature, supernatant acetone extract carefully decanted and kept aside. To the-residue in the flask, additional 50 millilitres of acetone are added and the process of hot extraction, cooling and decantation filtration continued. The acetone extracts pooled and desolventized to get improved purity oryzanol concentrate. The improved purity oryzanol concentrate is now treated with 70%alcohol, boiled for 15 minutes, cooled and then the supernatant alcohol layer drained off and solvent and fatty acids are recovered. The alcohol insoluble matter is now dried and then treated with hexane(IOOmillilitres) and boiled and kept aside at room temperature for crystallization. The next day the crystallized material was separated by filtration under 10inch vacuum on a Buchner funnel. The recovered product had an oryzanol content of >95% and was pale red in colour having a melting point of 142-146°C and with a recovery of 18.3%. Remaining material was found in the mother liquor which gave a concentrate of 50%oryzanol content. The oryzanol content at different stages of purification along with recovery and composition are given in Tables 2 & 3. Table 1. (Table Removed) Table 2 (Table Removed) Table 3. (Table Removed) Solubility : Completely soluble in acetone and chloroform yielding a solution, soluble in oil upto addition of 5%, beyond which, there is appearance of gel like precipitation in the solution. The main advantages of the process are: The concentrate and pure oryzanol may be used directly in capsules, foods, Pharmaceuticals and cosmetics,. The concentrate in addition contains polyunsaturated fatty acids present in rice bran oil in the form of glycerides and free fatty acids which are advantageous to disperse the concentrate effectively and quickly in the system. The oryzanol of 100% purity may directly be used for instant foods, Pharmaceuticals, cosmetics or wherever it is required to be added in pure form. We claim: 1. An improved process for recovery of oryzanol which comprises: a) extracting the oryzanol containing soap-stock with a mixture of a non-polar hydrocarbon solvent and an water miscible polar solvent in a ratio of 1:1 to 1:20 to obtain two phase aqueous and non¬aqueous, b) adding alkali solution to the non-aqueous phase, c) neutalising the said alkaline phase and extracting with a nonpolar organic solvent to get the oryzanol concentrate; which is then purified by, d) solvent degumming using a ketonic solvent followed by, e) solvent deacidification using an aqueous aliphatic alcohol and then f) crystallizing from a non-polar aliphatic hydrocarbon solvent to obtain oryzanol. 2. The process as claimed in claim (1), the polar solvent used is ethyl alcohol, methyl alcohol, propyl alcohol. 3.The process as claimed in claims (1) to (2), the non polar organic solvent for the separation of oil from oryzanol used is C5-C8 aliphatic hydrocarbon solvents. 4.The process as claimed in claims (1) to (3), wherein the alkali solution is selected from inorganic bases of sodium or potassium or calcium elements of 0.1N to 10N strengths. 5.The process as claimed in claims (1) to (4), the acid solution for neutralization is selected from hydrochloric, sulphuric or acetic acids of 0.1 N to 10N strengths. 6.The process as claimed in claims (1) to (5), the degumming solvent for separation of phospholipids and waxes from oryzanol used is from C3-C5 aliphatic ketonic solvents. 7.The process as claimed in claims (1) to (6), the deacidification solvent for separation of free fatty acids from oryzanol used aliphatic alcohols. 8.The process as claimed in claims (1) to (7), the solvent used for crystallization of oryzanol is selected from C5-C8 aliphatic hydrocarbon solvents. 9. An improved process for the recovery of oryzanol substantially as herein described with reference to the example.

Documents:

398-DEL-2003-Abstract-(03-11-2008).pdf

398-del-2003-abstract.pdf

398-DEL-2003-Claims-(03-11-2008).pdf

398-del-2003-claims.pdf

398-DEL-2003-Correspondence-Others-(03-11-2008).pdf

398-del-2003-correspondence-others.pdf

398-del-2003-correspondence-po.pdf

398-DEL-2003-Description (Complete)-(03-11-2008).pdf

398-del-2003-description (complete).pdf

398-DEL-2003-Form-1-(03-11-2008).pdf

398-del-2003-form-1.pdf

398-del-2003-form-18.pdf

398-DEL-2003-Form-2-(03-11-2008).pdf

398-del-2003-form-2.pdf

398-DEL-2003-Form-3-(03-11-2008).pdf

398-del-2003-form-3.pdf